ANTI- INFLAMMATORY EFFECTS OF BUCHHOLZIA CORIACEA ETHANOL LEAF-EXTRACT AND FRACTIONS IN FREUND'S ADJUVANT-INDUCED RHEUMATOID ARTHRITIC ALBINO RATS

The anti-inflammatory effects of Buchholzia coriacea ethanol leaf-extract, aqueous and ethylacetate fractions in Freund’s adjuvant-induced rheumatoid arthritic albino rats were investigated. The phytochemical constituents of the extract and fractions were analyzed using standard methods. A total of 216 albino rats were used for this study. Rats used for acute toxicity using Lorke method were 36, while 180 rats were randomly divided into 12 groups, each containing 15 rats for the sub-acute study. Group 1 served as normal control. Rheumatoid arthritis was induced in groups 2 to 12 by intradermal administration of 0.1 ml complete Freund’s adjuvant into the left hind paws of the albino rats. Group 2 (positive control) received normal saline while group 3 (standard control) received 5 mg/Kg indomethacin^TM (standard drug). Groups 4 to 12 were given ethanol leaf-extract, aqueous and ethylacetate fractions of Buchholzia coriacea at doses of 200, 400 and 800 mg/Kg body weight via oral intubation for 31 days. The inflammatory parameters were measured by standard laboratory procedures. Phytochemical constituents (mg/100g) in all samples were in the order of:

 Terpenoids>phenols>alkaloids>flavonoids>tannins>saponins>steroids>glycosides. Some phytochemicals were significantly (P<0.05) higher in the extract than fractions. The acute toxicity study showed that the ethanol leaf-extract caused no death to the rats even at 5000 mg/Kg body weight. Adjuvant administration significantly (P<0.05) increased the paw sizes and decreased the body weight of rats. In the arthritic rats, the levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), as well as the activity of adenosine deaminase (AD) were significantly (P<0.05) higher than the normal group. Treatment with standard drug and varied doses of the ethanol leaf-extract and fractions significantly (P<0.05) reduced these parameters to levels comparable to the normal control in a time and dose-dependent manner. The aqueous fraction had most significant (P<0.05) positive effect on most of the parameters studied at a dose of 800mg/Kg. The results show that Buchholzia coriacea possesses some phytochemicals which could be responsible for the anti-inflammatory potentials of the leaf extract and fractions. Therefore, this study provides scientific evidence that Buchholzia coriacea ethanol leaf-extract and fractions may be useful in the management of inflammation which is very common in rheumatoid arthritis.

Key words: Rheumatoid arthritis, Buchholzia coriacea, inflammation, anti-inflammatory.