Received: 16 June 2020
Accepted for publication: 18 February 2022
Slov Vet Res 2022; 59 (1): 31–45
DOI 10.26873/SVR-1150-2022
UDC 636.7.09:616-007.43-089:616-036
Original Research Article
Introduction
Rheumatoid arthritis (RA) is an autoimmune 
disorder. In individuals with autoimmune 
disorders, their immune system attack joints 
and some other tissues (1). Patients with these 
disorders have antibodies in their blood that target 
their own body tissues, resulting to inflammation 
(2). RA is a systemic (body-wide) disease, involving 
many organs of the body (3). Symptoms of RA 
include morning stiffness, joint pain, limited range 
ANTIOXIDANT EFFECT OF Buchholzia coriacea ETHANOL LEAF-
EXTRACT AND FRACTIONS ON FREUND’S ADJUVANT-INDUCED 
ARTHRITIS IN ALBINO RATS: A COMPARATIVE STUDY
Esther U. Alum1*, Udu A. Ibiam1, Emmanuel I. Ugwuja1, Patrick M. Aja1, Ikechuku O. Igwenyi1, Christian E. Offor1, Obasi U. Orji1, 
Chinyere Aloke2,3, Nkiru N. Ezeani1, Okechukwu P. C Ugwu1, Chinedu O. Egwu2
1Department of Biochemistry, Faculty of Science, Ebonyi State University, PMB 053, Abakaliki, Ebonyi State, 2Department of Medical 
Biochemistry, Faculty of Basic Medical Sciences, Alex Ekwueme Federal University, Ndufu Alike, Ikwo, Abakaliki, Ebonyi State, Nigeria, 
3Protein Structure-Function and Re-search Unit, School of Molecular and Cell Biology, Faculty of Science, University of the Witwatersrand, 
Braamfontein, Johannesburg, 2050, South Africa
*Corresponding author, Email: alumesther79@gmail.com
Abstract: Several studies have implicated reactive oxygen species in perpetuation of inflammation and subse-quent de-
struction of joints in patients with arthritis. Antioxidant effects of Buchholzia coriacea ethanol leaf-extract, aqueous and ethyl 
acetate fractions on oxidative stress indices in rheumatoid arthritic female Wistar albino rats were examined. 180 rats were 
randomly divided into 12 groups. Fifteen rats were placed in each group. Rats without arthritis were placed in Group 1. Rheuma-
toid arthritis was induced in groups 2 to 12 by intradermal injection of 0.1 ml complete Freund’s adjuvant into the left hind paws 
of rats. Group 2 (arthritic rats) did not receive any treatment but rather were given normal saline while group 3 (arthritic rats) 
received 5 mg/kg indomethacinTM (a standard drug). Rats in Groups 4 to 12 were administered the samples at doses of 200, 400 
and 800 mg/kg body weight. Freund’s ad-juvant administration led to inflammation and oxidative stress which were marked 
by significant (P<0.05) increase in paw sizes, oxidative stress markers and reduced body weight of the rats. Arthritic rats were 
treated with standard drug and samples (at varied doses) and this resulted to reversal of the trend of those parameters in a 
time and dose-dependent manner. Rats that received 800 mg/kg of the aqueous fraction displayed the best desirable result 
which was similar to the effect of indomethacin. Thus, Buchholzia coriacea ethanol extract and fractions may be useful in the 
management of oxidative stress which is very common among individuals with rheumatoid arthritis.
Key words: rheumatoid arthritis; Buchholzia coriacea; free radicals; oxidative stress; reactive oxygen species
of motion in the affected joints, fatigue, occasional 
redness, fever, firm bumps (nodules) under the skin 
and symptoms are always worse in the morning 
(4). RA is the most common rheumatic disease, 
affecting about 1 % of individuals world-wide (5). 
Male to female prevalence is 1:3 (6). Increased 
risk in family members of patients with RA may 
suggest that it can be hereditary (7). Increased 
risk among smokers and women may justify the 
role of environmental pollution and hormonal 
factors at perpetuating the inflammatory process 
and joint destruction (8).
The joint-damaging role of free radicals during 
inflammatory and other immunological response 
Zbornik_1_2022_22.4.22.indd   31 22/04/2022   09:53:33
 E.U. Alum, U.A. Ibiam, E.I. Ugwuja, P.M. Aja, I.O. Igwenyi, C.E. Offor, O.U. Orji, C. Aloke, N.N. Ezeani, O.P.C Ugwu, C.O. Egwu32
is paramount. This is because free radicals can 
be deposited into joint cartilage, attacking its 
proteoglycan and hence inhibits its synthesis (9).
RA is diagnosed by measurement of acute 
phase reactants, full blood count, and auto-
antibody such as rheumatoid factor and anti-
cyclic citrullinated peptide assay (14). 
The purpose of RA treatments is to inhibit 
disease severity, reduce symptoms and delay 
the onset of joint damage and other associated 
functional limitations (15).
Some RA medications include non-steroidal 
anti-inflammatory agents, steroids and anti-
tumor necrosis factor therapy (2, 3). Though 
these drugs reduce pain but they are unable to 
repair damaged tissues. They are mainly used for 
managing the pain and slowing the progression of 
RA. Therefore, there is no known drug for curing 
RA completely (16). 
About 80 % of world’s population depends 
on use of various plant parts in the prevention 
and treatment of diseases (17, 18). The adverse 
reaction and toxicity associated with the use of 
anti-inflammatory drugs, in addition to the high 
cost of the drugs have expeditiously promoted the 
use of natural plant products or procedures to 
manage RA locally (19). 
Buchholzia coriacea (B. coriacea) is in the 
family of Capparidaceae (20, 21). It is commonly 
called Wonderful kola, Musk tree, Cola pime, and 
Elephant cola. It has multiple medicinal values. 
It is useful in treatment of hypertension and also 
prevents premature aging. Its methanol seed 
extract has hypoglycemic, hypolipidemic, anti-lipid 
peroxidation and anti-ulcer effects (22, 23, 24, 25, 
26, 27). It has anti-microbial, antihelmintic and 
antifungal properties (28, 29, 30, 31). 
B. coriacea has been in use for quite some time 
by rural dwellers but there is scarce information 
on its antioxidant potentials. Therefore, this study 
was aimed at investigating the effect of B. coriacea 
ethanol leaf extract and fractions on oxidative 
stress markers in Freund’s adjuvant-induced 
arthritis in albino rats
Material and methods
Materials
Chemicals and reagents used were of analytical 
standard. Freund’s adjuvant was purchased from 
Sigma Aldrich Company, USA.
Biological materials: Biological materials used 
for this study were B. coriacea leaves and female 
Wistar albino rats.
Methods
Collection and Identification of Biological 
Materials: Leaves of B. coriacea were collected 
from Ngodo Village in Afikpo North Local 
Government Area of Ebonyi State, South-Eastern 
Nigeria. B. coriacea leaf was identified by a 
Taxonomist in Department of Applied Biology, 
Ebonyi State University, Abakaliki. Female 
albino rats (Wistar strain) weighing 121–146 g 
were obtained from the Department of Animal 
Science, University of Nigeria, Nsukka, Enugu. 
The rats were acclimatized for a period of two 
weeks in the Animal House of Divine Analytical 
Laboratory, Nsukka under standard laboratory 
conditions and fed with commercial rat feed and 
were allowed free access to clean water. The study 
was approved by the Departmental Institutional 
Ethical Committee of Biochemistry Department, 
Ebonyi State University Abakaliki, Nigeria with 
the Ethical approval number: EBSU/BCH/
ET/ 19/010. The guidelines agree with world 
standard for care and use of laboratory animals 
in research.
Preparation of extract and fractions: B. 
coriacea leaves were washed and shade dried and 
later pulverized in a grinder and sifted to obtain 
powdered sample. Eight hundred grammes of the 
sample were soaked in 2000 ml of ethanol for 48 
hours with intermittent rocking. Thereafter, it 
was filtered and filtrate was dried. The extracts 
were stored in airtight container. The dried crude 
ethanol leaf extract was fractionated in a glass 
column by eluting in succession with 500 ml water, 
500 ml ethyl acetate to obtain aqueous and ethyl 
acetate fractions, respectively. The crude ethanol 
leaf extract, aqueous and ethyl acetate fractions 
were subsequently used for other analyses.
Acute Toxicity Study: Modified Lorke (32) 
method was used in acute toxicity study. The 
modification was in the use of albino rats instead 
of mice. This is because the animal model of this 
work is albino rats. Thirty-six (36) rats were used 
for the acute toxicity test. The rats were weighed 
and fasted overnight before the acute toxicity 
testing. They were assigned to two experimental 
groups A and B. Group A which had four rats 
and served as the normal control group was 
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Antioxidant effect of Buchholzia coriacea ethanol leaf-extract and fractions on freund’s adjuvant-induced…       33
administered normal saline. The B group received 
crude ethanol leaf-extracts of B. coriacea. Group 
B animals were further sub-divided into eight 
groups with each group having four rats. The 
sub-groups (B1-B8) were administered orally with 
B. coriacea ethanol leaf-extracts at 200, 400, 800, 
1200, 1800, 2000, 3000 and 5000 mg/Kg body 
weight, respectively. All the experimental rats 
were allowed to have access to food and water and 
were observed for a 24 hours period for possible 
signs of toxicity and possible death.
Induction of arthritis in albino rats: Pearson 
method (33) was employed in induction of arthritis 
by intradermal injection of 0.1 ml Complete 
Freund’s adjuvant (CFA) into the left hind paws 
of rats in groups 2 to 12, according to their body 
weights. The paw sizes of all rats were checked 
with the aid of vernier caliper and this was done 
before and after administration of the adjuvant. 
It was observed that by day 10, arthritis had 
completely set in.
Rats and experimental groups: Female albino 
rats (Wistar) were used in this study and a total 
of 180 rats were utilized. Rats were distributed 
into 12 groups comprising fifteen rats in each 
group. The study lasted for 31 days and route of 
administration of extract and fractions was via 
oral intubation. The rats were grouped as follows: 
Group 1 comprises of non-arthritic rats that 
were given normal saline (1 ml/kg) while Group 
2 are arthritic rats that received normal saline 
(1 ml/kg). Arthritic rats treated with 5 mg/kg 
indomethacineTM (standard drug) were placed in 
Group 3 and this served as standard control. Rats 
in Groups 4-6 are arthritic rats treated with 200, 
400 and 800 mg/kg body weight of B. coriacea 
ethanol leaf-extract, respectively. Arthritic rats 
administered with 200, 400 and 800 mg/kg body 
weight of aqueous fraction of the crude ethanol 
leaf extract of B. coriacea were placed in Groups 
7-9, respectively. Groups 10-12 were arthritic rats 
treated with 200, 400 and 800 mg/kg body weight 
of ethyl acetate fraction of ethanol leaf extract of 
B. coriacea. Administration of drugs and samples 
was through oral intubation.
Determination of Body Weight and Paw Size: 
The changes in body weight and paw size were 
measured before and after adjuvant-induced 
arthritis with the aid of a weighing balance and 
vernier caliper, respectively. This was done daily. 
However, records of 10th, 17th, 24th and 31st day of 
study were used in data analysis.
Collection of Blood Samples for Biochemical 
Evaluation: Blood samples were humanely 
collected from three rats each from the groups 
by cardiac puncture via cervical dislocation on 
days 10, 17, 24, and 31 into plain sterile bottles. 
Thereafter, the blood samples were centrifuged 
at 3,000 rpm for 15 min and serum obtained for 
biochemical studies.
Determination of Oxidative stress indices: 
Malondialdehyde (MDA) was evaluated spec-
trophotometrically by measuring thiobarbituric 
acid reactive substance (TBARS) as outlined by 
Wallin et al. (34). Nitric oxide (NO) concentra-
tion was determined following the procedure 
described by Bories and Bories (35) based on 
the Griess reaction in which nitrite is reacted 
with sulfanilamide (diazotizing reagent) and 
N-(1-naphthyl) ethylendiamine (a coupling re-
agent) to produce an azo dye. NO being a la-
bile compound with a brief half-life is rapidly 
converted to nitrite and nitrate, in oxygenated 
aqueous solutions. Nitrite levels were measured 
after the enzymatic reduction of nitrate to ni-
trite with nitrate reductase. Reduced glutathi-
one (GSH) was assessed following the procedure 
outlined by Ellman (36). The mechanism was 
based on the fact that thiols react with Ellman’s 
reagent (5,5′-dithiobis-(2-nitrobenzoic acid) or 
DTNB), cleaving the disulfide bond to give 2-ni-
tro-5-thiobenzoate (TNB−), that in turn ionizes 
to the TNB2− dianion in water at neutral and al-
kaline pH. The concentration of Tocopherol was 
determined according to the method described 
by Desai (37). The activity of superoxide dismu-
tase (SOD) was determined as outlined by Mc-
Cord and Fridovich (38) based on the produc-
tion super-oxide radicals produced by xanthine 
and xanthine oxidase, which react with 2-(4-io-
dophenyl)-3-(4-nitrophenol)-5-phenyltetrazo-
lium chloride to form a red formazan dye. Cat-
alase was spectrophotometrically determined 
using the method explained by Sinha (39). 
The activity of glutathione peroxidase was 
assayed as outlined by Paglia and Valentine (40) 
based on the fact that GPX catalyzed the oxidation 
of glutathione by cumene hydroperoxide. In 
presence of the glutathione reductase and 
nicotinamide adenine dinucleotide phosphate 
(NADPH), the oxidized glutathione was 
immediately converted to the reduced form with 
concomitant oxidation of NADPH to NADP+. 
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Statistical analysis
All results were expressed as Mean ± Standard 
deviation (SD) and data were subjected to one-
way analyses of variance (ANOVA) with Duncan 
multiple range test for assessment of significant 
differences between means. A significance 
threshold of P<0.05 was taken for the analyses. 
Data were analyzed using IBM statistical package 
for social sciences (IBM-SPSS), version 20 (IBM, 
Corp., Atlanta, GA). Value of (P<0.05) was 
considered statistically significant.
Results
Acute toxicity study
The extracts were subjected to acute toxicity 
study in Wistar albino rats and the rats were 
monitored for 24 hours. No mortality was 
recorded and this revealed that the extracts were 
not toxic even at a high dose of 5,000 mg/kg. 
This formed the basis of our dose selection for 
the study.
Effect of Ethanol leaf-extract, Aqueous and 
Ethyl acetate Leaf Fractions of B. coriacea 
on Body weight and Paw Size of Adjuvant-
induced Arthritic Rats
A significant (P<0.05) increase in body weight 
of rats in the treated groups was observed 
relative to negative control as shown in Table 
1. There were significant (P<0.05) differences in 
body weight of rats treated with standard drug 
(indomethacin) relative to those treated with the 
extract, aqueous and ethyl acetate fractions. 
However, rats treated with ethyl acetate fraction 
had highest increase in body weight.
There was increase in paw size in the feet 
of rats injected with Freund’s adjuvant. A 
significant (P<0.05) reduction in paw size of rats 
treated with crude ethanol leaf-extract, aqueous 
and ethyl acetate leaf fractions of B. coriacea at 
200, 400 and 800 mg/kg body weight, relative to 
normal control was observed. The effect was both 
dose and time-dependent, as shown in Table 2. 
There were significant (P<0.05) differences in paw 
size of rats in all the treated groups. Maximum 
reduction of paw size with aqueous and ethyl 
acetate fractions at 200 mg/kg and 800mg/kg 
on day 31, respectively, occurred, relative to 
normal control. This effect was similar to that of 
the standard drug.
Effect of Ethanol leaf-extract, Aqueous and 
Ethyl acetate leaf fractions of B. coriacea on 
Oxidative Stress Indices in Adjuvant-induced 
Arthritic Rats
The results showed that the levels of MDA 
and NO increased in RA-induced rats relative 
to normal control as shown Tables 3 and 4, re-
spectively. Treatment with varied doses of the 
ethanol extract and fractions of the sample at 
200, 400 and 800 mg/kg body weight signifi-
cantly (P<0.05) reduced the levels of MDA and 
NO in a time-dependent manner. This reduc-
tion was comparable to that of indomethacinTM. 
Treatment with aqueous fraction at doses 200 
and 400 mg/kg on day 31 yielded the highest 
reduction in the level of NO, and this was bet-
ter than the effect of the indomethacinTM. Ac-
tivities of SOD, CAT and GPx were lowered in 
adjuvant-induced arthritic rats (Tables 5-7), re-
spectively. Treatment with standard drug and 
varied doses of the ethanol extract, aqueous and 
ethyl acetate fractions at 200, 400 and 800 mg/
kg body weight caused a significant (P<0.05) in-
crease in the activities of SOD, CAT and GPx, 
likewise an increase in the level of reduced GSH. 
The observed rise in the activity of SOD during 
treatment was time-dependent but there was no 
difference among the treated groups. Aqueous 
and ethyl acetate fractions at 800 mg/kg on day 
31 yielded a significantly (P<0.05) higher value 
in the activity of catalase and this effect was bet-
ter than that of standard drug. Treatment with 
ethanol extract and aqueous fraction on days 17 
and 24 yielded highest increase in the activity of 
GPx, when compared with indomethacinTM and 
ethyl acetate fraction. Treatment with aqueous 
fraction produced the highest increase in the 
level of GSH especially on day 31.
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Antioxidant effect of Buchholzia coriacea ethanol leaf-extract and fractions on freund’s adjuvant-induced…       35
Table 1: Effect of Ethanol Leaf-extracts, Aqueous and Ethyl acetate Fractions of B. coriacea on Body Weight (g) of 
Adjuvant-induced Arthritic Rats
Groups Day 10 Day 17 Day 24 Day 31
1 145.25 ± 9.53a 146.33 ± 7.57a 147.33 ± 0.58a 147.00 ± 5.29a
2 145.67 ± 8.72a 140.33 ± 4.04q 132.67 ± 5.13e 131.75 ± 3.79e
3 127.17 ± 3.86i 131.00 ± 7.00g 134.00 ± 3.46c 135.00 ± 2.00c
4 125.17 ± 3.33k 127.00 ± 2.65i 132.00 ± 2.65e 136.33 ± 2.08b
5 133.00 ± 3.46d 136.67 ± 4.04b 137.67 ± 1.53b 138.67 ± 2.52b
6 127.50 ± 2.28i 131.67 ± 3.06f 133.00 ± 3.00d 136.00 ± 3.00b
7 126.67 ± 2.57k 130.67 ± 3.06h 136.00 ± 2.65b 132.33 ± 1.53e
8 132.83 ± 4.09e 135.67 ± 1.53b 138.00 ± 2.65b 139.67 ± 3.51b
9 131.92 ± 2.39f 137.00 ± 1.00b 138.33 ± 1.53b 142.00 ± 1.00q
10 121.08 ± 2.94m 122.67 ± 2.52l 131.67 ± 2.08f 134.33 ± 1.53c
11 123.08 ± 2.75l 127.67 ± 1.15i 132.33 ± 4.93e 135.67 ± 5.03b
12 124.50 ± 2.47l 127.33 ± 3.06i 132.33 ± 3.21e 136.00 ± 2.65b
The degree of significance was set at P<0.05. Means (on the same column and row) with different superscripts are significantly 
different at P<0.05. This implies that comparison was done on both rows (point of sampling) and columns (among experimental 
groups). Values are mean ± standard deviation of 3 results obtained from 3 rats (n=3). BCE=B. coriacea Crude Ethanol extract, 
BCA=B. coriacea Aqueous fraction, BCZ=B. coriacea Ethyl acetate fraction. 1=normal control, 2= positive control, 3= standard 
control, 4=200mg/Kg BCE, 5=400mg/Kg BCE, 6=800mg/Kg BCE, 7=200mg/Kg BCA, 8=400mg/Kg BCA, 9=800mg/Kg BCA, 
10=200mg/Kg BCZ, 11=400mg/Kg BCZ, 12=800mg/kg BCZ
Table 2: Effect of Ethanol Leaf-extract, Aqueous and Ethyl acetate Fractions of B. coriacea on Paw size (mm) of 
Adjuvant-induced Arthritic Rats
Groups Beforeinduction Day 10 Day 17 Day 24 Day 31
1 2.14 ±0.02a 2.14 ± 0.01a 2.14 ± 0.02a 2.14 ±0.01a 2.14 ± 0.02a
2 2.20 ±0.03a 5.39 ±0.20d 6.59 ±0.22q 7.33 ±0.07x 7.78 ± 0.04z
3 2.14 ±0.07a 4.75 ±0.55e 3.89 ±0.59g 2.86 ±0.32gh 2.16 ± 0.22a
4 2.16 ±0.02a 5.60 ±0.20cd 4.53 ±0.42def 3.48 ±0.28efg 3.01 ± 0.14bc
5 2.14 ±0.03a 5.61 ±0.30cd 4.47 ±0.32def 4.00 ±0.22bcd 3.30 ± 0.35b
6 2.21 ±0.04a 5.57 ±0.33cd 4.44 ±0.27def 3.44 ±0.28fg 3.00 ± 0.45bc
7 2.16 ±0.02a 5.80 ±0.20bc 4.48 ±0.38def 3.36 ±0.30g 2.16 ± 0.34a
8 2.15 ±0.02a 5.73 ±0.24bc 4.64 ±0.23cdef 4.13 ± 0.10b 3.34 ± 0.28b
9 2.16 ±0.03a 5.97 ±0.40ab 5.03 ±0.67b 3.66 ±0.48efg 3.25 ± 0.27b
10 2.14 ±0.03a 5.68 ±0.32c 4.70 ±0.26bcde 3.73 ±0.34def 3.10 ±0.23bc
11 2.20 ±0.04a 5.68 ±0.16c 4.26 ±0.42f 3.80 ±0.43cde 3.08 ±0.41bc
12 2.16 ±0.03a 5.70 ±0.40ac 4.33 ±0.55ef 3.53 ±0.40efg 2.16 ± 0.44a
The degree of significance was set at P<0.05. Means (on the same column and row) with different superscripts are significantly 
different at P<0.05. This implies that comparison was done on both rows (point of sampling) and columns (among experimental 
groups). Values are the mean ± standard deviation of 3 results obtained from 3 rats (n=3). BCE=B. coriacea Crude Ethanol extract, 
BCA=B. coriacea Aqueous leaf fraction, BCZ=B. coriacea Ethyl acetate leaf fraction. 1=normal control, 2=positive control, 3=stan-
dard control, 4=200 mg/Kg BCE, 5=400 mg/Kg BCE, 6=800 mg/Kg BCE, 7=200 mg/Kg BCA, 8=400 mg/Kg BCA, 9=800 mg/Kg 
BCA, 10=200 mg/Kg BCZ, 11=400 mg/Kg BCZ, 12=800 mg/Kg BCZ
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Groups Day 10 Day 17 Day 24 Day 31
1 6.60 ± 0.27a 6.81 ± 0.19a 6.61 ± 0.58a 6.62 ± 0.42a
2 6.62 ± 0.40a 6.83 ± 0.55a 7.70 ± 0.54a 8.27 ± 0.52a
3 6.68 ± 0.34a 6.20 ± 0.66b 5.68 ± 0.25h 5.70 ± 0.25c
4 6.11 ± 0.61a 6.03 ± 0.83b 5.84 ± 0.08b 5.33 ± 0.30k
5 6.29 ± 0.65a 6.43 ± 0.41a 5.74 ± 0.14c 5.57 ± 0.47f
6 6.35 ± 0.20a 5.68 ± 0.24h 5.70 ± 0.17c 5.54 ± 0.23g
7 6.50 ± 0.34a 5.89 ± 0.16b 5.83 ± 0.11b 5.55 ± 0.17f
8 6.82 ± 0.37a 6.08 ± 0.28b 5.92 ± 0.20b 5.48 ± 0.08i
9 6.93 ± 0.15a 5.76 ± 0.13c 5.80 ± 0.12b 5.59 ± 0.10f
10 6.62 ± 0.43a 5.71 ± 0.13h 5.80 ± 0.07b 5.38 ± 0.23j
11 6.76 ± 0.13a 5.77 ± 0.03c 5.74 ± 0.04c 5.67 ± 0.27d
12 6.66 ± 0.09a 5.80 ± 0.29b 5.71 ± 0.11c 5.52 ± 0.21h
Table 3: Effect of Ethanol leaf-extract, Aqueous and Ethyl acetate leaf fractions of B. coriacea on Malondialdehyde 
(MDA) level (Nmol/g) of Adjuvant-induced Arthritic Rats
The degree of significance was set at P<0.05. Means (on the same column and row) with different superscripts are significantly 
different at P<0.05. This implies that comparison was done on both rows (point of sampling) and columns (among experimental 
groups). Values are the mean ± standard deviation of 3 results obtained from 3 rats (n=3). BCE=B. coriacea Crude Ethanol ex-
tract, BCA=B. coriacea Aqueous fraction, BCZ=B. coriacea Ethyl acetate fraction. 1=normal control, 2=positive control, 3=stan-
dard control, 4=200 mg/kg BCE, 5=400 mg/kg BCE, 6=800 mg/kg BCE, 7=200 mg/kg BCA, 8=400 mg/kg BCA, 9=800 mg/kg 
BCA, 10=200 mg/kg BCZ, 11=400 mg/kg BCZ, 12=800 mg/kg BCZ
Table 4: Effect of Ethanol leaf-extract, Aqueous and Ethyl acetate leaf fractions of B. coriacea on Nitric oxide (NO) 
level (Nmol/ml) of Adjuvant-induced Arthritic Rats
Groups Day 10 Day 17 Day 24 Day 31
1 20.32 ± 1.02a 19.78 ± 0.68a 20.35 ± 0.07a 19.21 ± 0.91b
2 17.41 ± 0.95e 18.23 ± 1.00c 19.42 ± 0.15b 22.01 ± 0.07a
3 19.02 ± 2.10b 18.65 ± 0.48c 17.92 ± 1.13d 17.91 ± 2.20d
4 18.71 ± 0.48c 18.38 ± 0.65c 18.35 ± 0.45c 16.81 ± 0.47h
5 18.45 ± 1.54c 18.31 ± 0.82c 18.39 ± 0.46c 16.63 ± 0.59i
6 18.88 ± 0.46d 18.19 ± 1.08c 17.61 ± 0.43c 16.45 ± 0.16j
7 18.79 ± 0.27b 18.66 ± 0.38c 17.99 ± 0.53d 16.34 ± 0,58k
8 18.41 ± 0.55c 18.31 ± 0.83c 17.86 ±0.70d 16.95 ± 0.27g
9 17.92 ± 0.36d 17.72 ± 0.94d 17.91 ± 0.87d 17.86 ± 0.21d
10 18.64 ± 0.38c 18.30 ± 0.42c 17.98 ± 0.67d 16.72 ± 0.50h
11 18.19 ± 1.70c 18.28 ± 0.86c 17.89 ± 1.59d 17.05 ± 0.36f
12 20.97 ± 0.35a 18.34 ± 9.42c 18.11 ± 1.18c 18.14 ± 0.43c
The degree of significance was set at P<0.05. Means (on the same column and row) with different superscripts are significantly 
different at P<0.05. This implies that comparison was done on both rows (point of sampling) and columns (among experimental 
groups). Values are the mean ± standard deviation of 3 results obtained from 3 rats (n=3). BCE=B. coriacea Crude Ethanol ex-
tract, BCA=B. coriacea Aqueous fraction, BCZ=B. coriacea Ethyl acetate fraction. 1=normal control, 2=positive control, 3=stan-
dard control, 4=200 mg/kg BCE, 5=400 mg/kg BCE, 6=800 mg/kg BCE, 7=200 mg/kg BCA, 8=400 mg/kg BCA, 9=800 mg/kg 
BCA, 10=200 mg/kg BCZ, 11=400 mg/kg BCZ, 12=800 mg/kg BCZ
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Antioxidant effect of Buchholzia coriacea ethanol leaf-extract and fractions on freund’s adjuvant-induced…       37
Groups Day 10 Day 17 Day 24 Day 31
1 23.10 ± 0.98a 23.11 ± 2.08a 23.11 ± 1.29a 23.21 ± 1.91a
2 22.25 ± 1.67c 20.72 ± 0.57d 19.50 ± 0.79e 18.47 ± 1.22e
3 22.23 ± 0.92c 23.07 ± 0.56a 24.56 ± 1.16a 26.00 ± 0.48a
4 21.91 ± 1.01c 22.56 ± 1.04c 22.80 ± 0.45b 24.21 ± 0.70a
5 20.91 ± 1.93d 21.96 ± 0.77c 21.41 ± 0.52c 25.21 ± 0.43a
6 22.13 ± 1.51c 21.51 ± 0.18c 21.64 ± 0.83d 22.88 ± 0.73b
7 22.16 ± 0.22c 22.53 ± 1.41c 23.42 ± 1.36a 25.88 ± 0.72a
8 21.14 ± 1.17d 21.67 ± 0.75c 22.30 ± 0.38d 23.48 ± 0.23a
9 21.88 ± 0.66c 22.20 ± 1.09c 24.21 ± 0.56a 26.17 ± 0.32a
10 21.44 ± 1.54d 22.17 ± 0.14c 24.28 ± 0.70a 26.41 ± 1.09a
11 20.91 ± 1.61d 21.55 ± 0.89d 23.41 ± 0.16a 26.48 ± 0.42a
12 20.47 ± 1.18d 20.63 ± 0.09d 23.03 ± 1.65a 25.28 ± 0.26a
Table 5: Effect of Ethanol leaf-extract, Aqueous and Ethyl acetate leaf fractions of B. coriacea on SOD activity 
(u/mg) of Adjuvant-induced Arthritic Rats
The degree of significance was set at P<0.05. Means (on the same column and row) with different superscripts are significantly 
different at P<0.05. This implies that comparison was done on both rows (point of sampling) and columns (among experimental 
groups). Values are the mean ± standard deviation of 3 results obtained from 3 rats (n=3). BCE=B. coriacea Crude Ethanol ex-
tract, BCA=B. coriacea Aqueous fraction, BCZ=B. coriacea Ethyl acetate fraction. 1=normal control, 2=positive control, 3=stan-
dard control, 4=200 mg/kg BCE, 5=400 mg/kg BCE, 6=800 mg/kg BCE, 7=200 mg/kg BCA, 8=400 mg/kg BCA, 9=800 mg/kg 
BCA, 10=200 mg/kg BCZ, 11=400 mg/kg BCZ, 12=800 mg/kg BCZ
Table 6: Effect of Ethanol leaf-extract, Aqueous and Ethyl acetate leaf fractions of B. coriacea on Catalase activity 
(u/mg) of Adjuvant-induced Arthritic Rats
Groups Day 10 Day 17 Day 24 Day 31
1 67.67 ± 3.02a 67.84 ± 1.26a 66.52 ± 2.03a 66.63 ± 5.57a
2 58.49 ± 2.73c 55.79 ± 0.41d 52.21 ± 4.34f 45.62 ± 3.16g
3 57.48 ± 2.46d 59.21 ± 1.14b 58.42 ± 2.66c 61.60 ± 1.41a
4 53.25 ± 2.77f 54.19 ± 1.66e 57.31 ± 0.80d 59.84 ± 1.12a
5 54.59 ± 3.25d 55.63 ± 2.35d 57.92 ± 4.32d 59.66 ± 3.22a
6 55.16 ± 2.51d 56.04 ± 1.10d 55.68 ± 1.25d 60.44 ± 0.63a
7 55.44 ± 2.20d 57.57 ± 0.74d 57.58 ± 2.16d 57.99 ± 2.41d
8 55.56 ± 3.13d 57.52 ± 2.52d 56.52 ± 1.50d 58.21 ± 2.28c
9 55.59 ± 0.54d 55.32 ± 2.38d 56.56 ± 4.36d 62.14 ± 1.55a
10 53.90 ± 3.64e 55.95 ± 0.30d 55.61 ± 3.06d 59.65 ± 1.96a
11 54.20 ± 2.74e 54.61 ± 1.32d 56.24 ± 0.97d 59.35 ± 4.88a
12 57.25 ± 2.84d 57.30 ± 2.39d 58.97 ± 2.54c 59.81 ± 1.76a
The degree of significance was set at P<0.05. Means (on the same column and row) with different superscripts are significantly 
different at P<0.05. This implies that comparison was done on both rows (point of sampling) and columns (among experimen-
tal groups). Values are the mean ± standard deviation of 3 results obtained from 3 rats (n=3). BCE=B. coriacea Crude Ethanol 
extract, BCA=B. coriacea Aqueous fraction, BCZ=B. coriacea Ethyl acetate fraction. 1=normal control, 2=positive control, 
3=standard control, 4=200 mg/kg BCE, 5=400 mg/kg BCE, 6=800 mg/kg BCE, 7=200 mg/kg BCA, 8=400 mg/kg BCA, 9=800 
mg/kg BCA, 10=200 mg/kg BCZ, 11=400 mg/kg BCZ, 12=800 mg/kg BCZ
Zbornik_1_2022_22.4.22.indd   37 22/04/2022   09:53:34
 E.U. Alum, U.A. Ibiam, E.I. Ugwuja, P.M. Aja, I.O. Igwenyi, C.E. Offor, O.U. Orji, C. Aloke, N.N. Ezeani, O.P.C Ugwu, C.O. Egwu38
Groups Day 10 Day 17 Day 24 Day 31
1 23.64 ± 1.18b 24.37 ± 0.72a 24.43 ± 2.66a 23.89 ± 0.24b
2 21.61 ± 2.16b 20.76 ± 0.41d 19.51 ± 2.70e 18.21 ± 0.66f
3 20.43 ± 0.69c 21.38 ± 0.51b 22.26 ± 2.47b 22.31 ± 0.85b
4 20.63 ± 0.42c 21.42 ± 1.11b 22.31 ± 1.04b 21.58 ± 0.17b
5 19.82 ± 1.23e 20.71 ± 0.56c 21.83 ± 1.02b 21.55 ± 0.59b
6 20.19 ± 0.21d 20.63 ± 0.66c 21.16 ± 0.38b 22.05 ± 1.21b
7 20.73 ± 1.02c 21.07 ± 0.55b 21.96 ± 0.62b 22.21 ± 0.39b
8 20.91 ± 0.64b 21.08 ± 0.54b 21.30 ± 0.52b 22.09 ± 0.61b
9 20.15 ± 0.98d 21.23 ± 0.46b 21.52 ± 1.42b 22.84 ± 0.98b
10 21.23 ± 0.78b 20.51 ± 0.18c 21.64 ± 1.35b 21.64 ± 0.90b
11 21.72 ± 1.67b 20.76 ± 0.55c 21.26 ± 0.13b 22.70 ± 1.06b
12 21.31 ± 0.62b 21.04 ± 0.47b 21.36 ± 0.80b 22.50 ± 0.59b
Table 7: Effect of Ethanol leaf-extract, Aqueous and Ethyl acetate leaf fractions of B. coriacea on glutathione 
peroxidase (GPx) activity (u/l)) of Adjuvant-induced Arthritic Rats
Groups Day 10 Day 17 Day 24 Day 31
1 26.45±2.37a 26.82±0.59a 26.760±0.03a 25.99±0.08a
2 22.88±0.71d 19.18±0.62h 16.36±0.18i 10.17±1.43d
3 18.57±0.86h 21.99±0.39f 22.03±0.41e 22.38±0.76c
4 17.09±0.24i 20.42±0.50g 23.80±0.59c 24.82±1.21a
5 15.60±0.25j 19.31±0.33h 22.94±0.58d 25.54±0.33a
6 15.91±0.61j 20.12±1.54g 22.34±1.80d 25.62±0.70a
7 15.26±0.55e 22.53±0.34d 23.54±0.40c 24.51±0.57a
8 16.27±0.97i 22.72±0.32d 22.85±0.14d 25.16±1.46a
9 16.27±0.20i 21.77±0.89f 24.02±0.38b 25.12±0.88a
10 15.46±0.66j 23.22±1.48c 25.14±0.15a 25.48±0.53a
11 15.22±0.43j 22.40±1.63d 22.95±0.73d 23.70±1.11b
12 15.29±0.90j 21.91±1.03f 23.60±0.70c 24.36±0.65a
Table 8: Effect of Ethanol leaf-extract, Aqueous and Ethyl acetate leaf fractions of B. coriacea on reduced glutathione 
(GSH) level (Umol/l) of Adjuvant-induced Arthritic Rats
The degree of significance was set at P<0.05. Means (on the same column and row) with different superscripts are significantly 
different at P<0.05. This implies that comparison was done on both rows (point of sampling) and columns (among experimental 
groups). Values are the mean ± standard deviation of 3 results obtained from 3 rats (n=3). BCE=B. coriacea Crude Ethanol ex-
tract, BCA=B. coriacea Aqueous fraction, BCZ=B. coriacea Ethyl acetate fraction. 1=normal control, 2=positive control, 3=stan-
dard control, 4=200 mg/kg BCE, 5=400 mg/kg BCE, 6=800 mg/kg BCE, 7=200 mg/kg BCA, 8=400 mg/kg BCA, 9=800 mg/kg 
BCA, 10=200 mg/kg BCZ, 11=400 mg/kg BCZ, 12=800 mg/kg BCZ
The degree of significance was set at P<0.05. Means (on the same column and row) with different superscripts are significantly 
different at P<0.05. This implies that comparison was done on both rows (point of sampling) and columns (among experimental 
groups). Values are the mean ± standard deviation of 3 results obtained from 3 rats (n=3). BCE=B. coriacea Crude Ethanol ex-
tract, BCA=B. coriacea Aqueous fraction, BCZ=B. coriacea Ethyl acetate fraction. 1=normal control, 2=positive control, 3=stan-
dard control, 4=200 mg/kg BCE, 5=400 mg/kg BCE, 6=800 mg/kg BCE, 7=200 mg/kg BCA, 8=400 mg/kg BCA, 9=800 mg/kg 
BCA, 10=200 mg/kg BCZ, 11=400 mg/kg BCZ, 12=800 mg/kg BCZ
Zbornik_1_2022_22.4.22.indd   38 22/04/2022   09:53:34
Antioxidant effect of Buchholzia coriacea ethanol leaf-extract and fractions on freund’s adjuvant-induced…       39
Discussion 
In the first week following induction of arthritis, all 
adjuvant-induced arthritic rats showed a significant 
(P<0.05) decrease in the body weight relative to 
rats in normal control group. A significant (P<0.05) 
increase in the body weight of rats was observed 
in all the treated groups while progressive weight 
loss was observed in the untreated-arthritic group 
till the end of the study. Our present results are in 
agreement with previous studies that showed that 
Complete Freund’s Adjuvant (CFA)-injected rats 
showed decreases in body weight relative to non-
arthritic rats (41). Administration of CFA leads to 
increase in leptin level, anorexia and weight loss 
(42). In this study, we speculate that the cause of the 
decrease in body weight on injection of CFA might 
be due to increase in leptin level in the arthritic 
rats. Leptin is a hormone secreted by fat cells and 
is known for suppressing hunger signals, also has 
influences on the immune system. Elevated level 
of leptin contributes to chronic inflammation by 
up-regulating inflammatory cytokines (like tumor 
necrosis factor-alpha, TNF-α; interleukins, IL-1β, 
and IL-6) (43). Elevated levels of pro-inflammatory 
cytokines could exert a strong effect on protein 
and energy metabolism by promoting muscle 
breakdown. Increased catabolism leads to resting 
energy expenditure culminating to weight loss 
and reduced lean body mass (44). 
Inflammation can also cause a decrease in 
absorption capacity of the intestine. Elmali et al. 
(2005) (45) reported a restoration of absorption 
capacity of the intestine upon treatment with anti-
inflammatory drugs. Thus, increased body weight 
of the arthritic rats during the course of treatment 
with an anti-inflammatory drug (indomethacin) 
and varied doses of the extract and fractions 
could be due to the reduction of the inflammatory 
cytokines and subsequent decrease in protein and 
muscle breakdown.  It could also be due to the 
restoration of absorption capacity of the intestine. 
Edema is one of the fundamental actions of 
acute inflammation and is an essential parameter 
to be considered when evaluating compounds 
with potential anti-inflammatory activity (46, 47). 
In this study, there was a two-fold increase in 
paw size in the feet of rats injected with Freund’s 
adjuvant. A significant (P<0.05) reduction in paw 
size of rats treated with standard drug, ethanol 
leaf-extract, aqueous and ethyl acetate leaf 
fractions of B. coriacea at varied, was observed. 
Previous authors have also reported a significant 
reduction in paw size of rats on treatment with 
medicinal plants (48, 49).
Oxidative stress is a situation in the biological 
science in which there is an imbalance between 
oxidants and antioxidants in favor of the oxidants, 
culminating in interference of redox signaling 
and control and/or molecular injury (50). In 
normal physiological processes, reactive oxygen 
species (ROS) are formed and they play crucial 
functions in cell signaling and tissue homeostasis 
(51). Nevertheless, their excessive production 
culminates in severe alterations to cell components 
and augment various pathogenesis, such as 
lipids, proteins, and DNA damage (52). Sequel to 
high level of polyunsaturated fatty acids (PUFAs) 
in cellular membranes or organelle membrane, 
they are prone to ROS damage, which is referred 
to as lipid peroxidation. Thus, lipid peroxidation 
is a process that involves the removal of electrons 
from lipids by free radical species such as oxyl 
radicals, peroxyl radicals, and hydroxyl radicals 
leading subsequently to the production of reactive 
intermediates that can undergo further reactions. 
This causes damage to phospholipids and function 
as cell death signal which induces programmed 
cell death. Hence, oxidized phospholipid mediates 
important function in several inflammatory 
disorders and frequently mediate proinflammatory 
alteration (53). 
There exist three major classes of antioxidant 
enzymes in all body cells which include the 
catalases, superoxide dismutases (SOD), and 
glutathione peroxidases (GPX). These enzymes 
play vital functions in cells’ homeostasis. Their 
induction is a reflection of specific response to 
pollutant oxidative stress (54). These enzymic 
and non-enzymic antioxidants such as 
glutathione (GSH) have the ability to prevent or 
retard the oxidation of macromolecules. These 
antioxidants retard or terminate these chain 
reactions by mopping up free radicals or via 
inhibition of other oxidation reactions by being 
oxidized themselves (55).
Chemical composition analysis of B. coriacea 
has been investigated by previous studies. Phyto-
chemicals present in B. coriacea ethanol leaf-ex-
tract and fractions are terpenoids, phenols, alka-
loids, flavonoids, tannins, saponins and steroids 
(56). Other authors have also corroborated this 
finding (57, 58, 59, 60, 61). Phytochemicals can 
act as antioxidants (e.g, flavonoids, alkaloids, tan-
Zbornik_1_2022_22.4.22.indd   39 22/04/2022   09:53:34
 E.U. Alum, U.A. Ibiam, E.I. Ugwuja, P.M. Aja, I.O. Igwenyi, C.E. Offor, O.U. Orji, C. Aloke, N.N. Ezeani, O.P.C Ugwu, C.O. Egwu40
nins, saponins and terpenoids) antiproliferative 
and anti-inflammatory compounds for prevention 
of chronic diseases (62, 63).
The results of our study revealed increased 
oxidative stress in adjuvant-induced arthritic 
rats as evidenced by increased lipid peroxidation 
product-MDA and NO production, and impaired 
enzymatic and non-enzymatic antioxidant 
defense system of the body (Tables 3- 8). The 
raised MDA (a consequence of increased extent of 
lipid peroxidation) might be due to the increased 
formation of ROS which tends to increase 
abundantly during chronic inflammation and 
could result to damage to tissues. Other authors 
have also reported increase in MDA in liver and 
brain of rats with arthritis (64, 65, 66). Elevated 
level of MDA has been found in the serum, 
plasma and erythrocytes of RA patients (13, 67). 
Administration of standard drug and samples 
reduced levels of MDA as shown in Table 3.
Some functions of NO include immune response, 
neural communication and blood pressure 
maintenance (68). In this study, increased NO level 
portends oxidative stress and this corroborates 
previous findings as reported by other authors (64, 
13, 67). However, Veselinovic et al. (69) reported 
unaltered level of NO in the plasma of RA patients. 
The increase in the level of NO in the plasma of 
arthritic rats might be due to the hyperactivity of 
the NO forming enzyme, nitric oxide synthase (70). 
The observed reduced SOD activity might be due to 
its depletion caused by increased oxidative stress 
that occur during inflammatory process.
This decreased erythrocyte SOD activity is in 
agreement with other studies as well (13, 71, 72, 
73, 74, 75). However, increased (69, 76), or even 
unaltered SOD activity (77) has also been reported 
by some groups. 
Catalase is an enzyme that catalyses the 
conversion of hydrogen peroxide into water and 
oxygen. This protects cells from harmful effects 
that accumulated hydrogen peroxide could have 
caused. From our result, catalase activity is lowered 
in arthritic rats and this might be as a result of 
catalase being used up by hydrogen peroxide.
Diminished catalase activity in brain and liver 
of arthritic rats have been reported by previous 
authors (65, 66). This result is in tandem with 
other findings using human beings (54, 13, 71, 
74). However, some groups have also reported 
unaltered catalase activity in RA patients (64, 75, 
78, 72). 
We also observed a significant decrease in GPx 
activity in the adjuvant-induced arthritic rats 
(Table 7). This is in line with the findings of other 
studies using humans (79, 73, 72). However, two 
studies reported an increase on GPx activity in 
RA patients (80, 76). However, three study groups 
did not report any differences between cases and 
controls in GPx activity in RA patients (75, 78, 74). 
We noticed significantly low levels of GSH in 
arthritic rats as compared to the control rats (healthy 
rats) (Table 8). GSH is a sulfhydryl molecule that 
acts as a defense system in the body. It functions 
as an intracellular reductant in redox reactions 
taking place in the human body by protecting 
cellular components from damage caused by 
ROS. The observed low level of GSH in plasma of 
arthritic rats has also been reported by previous 
authors (64, 75, 79, 74, 81, 82, 13). Veselinovic et 
al. (69) reported that GSH level was unchanged in 
RA patients. This contradicting report by various 
authors could be due to differences in RA severity 
and response to treatments by rats/or patients. 
ROS are highly reactive chemical species that 
have the potential to damage lipids, proteins 
and deoxyribonucleic acid (DNA) in joint tissues. 
ROS are required in maintaining redox state 
of cells. Other functions include cell signaling, 
differentiation, proliferation, growth, apoptosis and 
phagocytosis. However, if the concentrations of 
ROS are increased beyond physiological conditions 
they can damage macromolecules like lipids in the 
cell membranes, proteins and nucleic acids (83, 
81). Oxidative stress results if the concentration 
of oxidants is higher than antioxidants (84). 
Under this condition, redox signaling is disrupted 
leading to macromolecular damage (85, 86, 87). 
The damaging ROS is annulled by the action of 
antioxidants. Enzymatic antioxidant response is 
carried out by SOD, catalase, GPx, glutathione 
reductase and transferase while non-enzymatic 
antioxidant includes the action of vitamins (e.g. 
A, C, and E), β-carotene, some minerals (e.g. 
copper, zinc, manganese, and selenium), GSH and 
some phytochemicals (e.g. flavonoids, terpenoids, 
alkaloids) (85, 64).
A large number of authors reported that ROS are 
implicated in inflammation and destruction in the 
joints of arthritic animals and RA patients (64, 88, 
13, 85, 89, 90, 91).  Oxidative stress is implicated 
in damaging of joints due to RA (87). There is strong 
evidence that ROS are highly involved in cartilage 
degradation in experimental arthritic rats (92).
Zbornik_1_2022_22.4.22.indd   40 22/04/2022   09:53:34
Antioxidant effect of Buchholzia coriacea ethanol leaf-extract and fractions on freund’s adjuvant-induced…       41
Oxidative stress can also impair DNA mismatch 
repair mechanism which may result to an 
increase in the formation of DNA adducts in the 
joints thereby aggravating the disease symptoms 
(93).  Phytochemicals serve as sources of natural 
compound for developing novel drugs. This is 
because of their antioxidant and anti-inflammatory 
roles in management of inflammatory diseases 
such as RA. The presence of antioxidant minerals 
(e.g., copper, zinc, manganese, and selenium) 
and vitamins (A, C and E) in B. coriacea is well-
documented (56, 94). Thus, the anti-RA effect 
exerted by the samples could be attributed to the 
action of these antioxidants present in the plant. 
However, limitation of this study is the small 
number of rats sampled at each point. 
Conclusion
Induction of RA caused oxidative stress 
evidenced by elevation of MDA and NO and 
diminished activities of antioxidants: SOD, GPx, 
Catalase and GSH. Administration of samples to 
rats led to decrease in oxidative stress and boosting 
of the antioxidants. This study has demonstrated 
in vivo the therapeutic potential of leaf extract 
and ethyl acetate fraction of B. coriacea at curbing 
oxidative stress and hence a potential alternative 
to synthetic drugs in the management of oxidative 
stress in RA patient.
Ethics approval and consent to participate was 
adequately sought.
Acknowledgements
Authors acknowledge the management of Divine 
Analytical Laboratory, Nsukka, Nigeria, where this 
research was carried out.
Consent for publication: All authors granted 
consent for this work to be published. Availability of 
data and material: Adequate. Competing interests: 
None. Funding: None.
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ANTIOKSIDATIVNI UČINEK ETANOLNEGA IZVLEČKA IN FRAKCIJ LISTOV Buchholzia 
coriacea NA FREUNDOV ADJUVANTNI ARTRITIS PRI ALBINO PODGANAH: 
PRIMERJALNA ŠTUDIJA
E. U. Alum, U. A. Ibiam, E. I. Ugwuja, P.M. Aja, I. O. Igwenyi, C. E. Offor, O. U. Orji, C. Aloke, N. N. Ezeani, O. P. C Ugwu, 
C. O. Egwu
Izvleček: V več študijah je bil nakazan pomen reaktivnih kisikovih zvrsti pri ohranjanju vnetja in poznejšem uničenju sklepov 
pri pacientih z osteoartritisom. Proučevali smo antioksidantivne učinke etanolovega izvlečka ter vodnih in etil acetatnih frak-
cij listov Buchholzia coriacea na kazalce oksidativnega stresa pri samicah albino podgan Wistar z revmatoidnih artritisom. 
180 podgan smo naključno porazdelili v 12 skupin. V vsaki skupini je bilo 15 podgan. Podgane brez artritisa so bile uvrščene 
v skupino 1. V skupinah 2 do 12 so bile podgane z revmatoidnim artritisom, povzročenim z  intradermalno injekcijo 0,1 ml Fre-
undovega kompletnega adjuvansa v zadnjo levo taco podgan. Skupina 2 (podgane z artritisom) ni bila zdravljena, prejela je 
fiziološko raztopino, skupina 3 (podgane z artritisom) pa je prejela 5 mg/kg indometacinaTM (standardno zdravilo). Podgane v 
skupinah 4 do 12 so prejele vzorce adjuvansa v odmerkih 200, 400 in 800 mg/kg telesne mase. Aplikacija Freundovega adju-
vansa je povzročila vnetje in oksidativni stres, kar se je kazalo v značilnem (p<0.05) povišanju velikosti tac in kazalcev oksida-
tivnega stresa ter zmanjšanju telesne teže podgan. Podgane z artritisom so bile zdravljene s standardnim zdravilom in vzorci 
adjuvansa (v različnih odmerkih), kar je vodilo v obrat trenda teh parametrov v odvisnosti od časa in odmerka. Najboljši rezultat, 
podoben učinku indometacina, je bil pri podganah, ki so prejele 800 mg/kg vodne frakcije adjuvansa. Etanolni izvleček in frak-
cije listov Buchholzia coriacea bi zato lahko bili uporabni pri obvladovanju oksidativnega stresa, ki se zelo pogosto pojavlja pri 
posameznikih z revmatoidnim artritisom.
Ključne besede: revmatoidni artritis; Buchholzia coriacea; prosti radikali; oksidativni stres; reaktivne kisikove zvrsti
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