Anti-Inflammatory And Antinociceptive Effects Of Ethanol Extract Of Ritchiea Capparoides Root-Bark In Rats

Abstract

The effects of ethanol extract of Ritchiea capparoides root-back on egg albumin- induced inflammation in rat hind paw, hypotonicity induced haemolysis of human red blood cells, acetic acid–induced nociception in albino mice, phospholipase A2 activity and calcium chloride-induced platelet aggregation were studied. Twenty five adult albino rats of either sex (120 to 200 g) and 25 adult albino mice of either sex of weights 40-80 g were divided into ten experimental groups of five rats and five mice eac/.h. Five groups of the rats were used for the anti- inflammatory tests, while the other five groups of the mice were used for analgesic test. Inflammation was induced by injecting 0.1 ml of fresh egg albumin into the subplantar surface of the right hind paw of the rats. Ethanol extract of Ritchiea capparoides (100, 200 and 400 mg/kg b. w.) and indomethacin (100 mg/kg b. w.) were administered intraperitoneally to separate groups of the rats one hour before inducing inflammation. The control group received equivalent volume of distilled water (vehicle). Nociception was induced in the mice by the administration of acetic acid (50mg/kg b. w.) using standard procedures. Ritchiea capparoides extract (100, 200 and 400 mg/kg b. w.) and aspirin (200 mg/kg b. w.) were administered orally to separate groups of the mice thirty minutes before inducing nociception. The control group received equivalent volume of distilled water (vehicle). The effect of the extract on hypotonicity-induced haemolysis, calcium chloride induced platelet aggregation and phospholipase A2 activity were also evaluated. From the results of the study, rats treated with 100, 200 and 400 mg/kg body weight of the extract showed significant reduction of oedema after five hours of treatment with inhibition of 89.10 %, 85.03 % and 87.00 % respectively and treatment with 200 and 400 mg/kg body weights significantly reduced the number of writhings induced by acetic acid in mice with inhibition of 42.11 % and 99.61 % respectively. The R. capproides extract caused a reduction in the haemolysis induced by distilled water, The extract (1.0, 2.0, 3.0, 4.0, and 5.0 mg/ml) significantly (p < 0. 05) inhibited the lysis of human red blood cells. The absorbance values for the extract were 0.408 ± 0.002, 0.421 ± 0.002, 0.452 ± 0.001, 0.577 ± 0.002 and 0.588 ± 0.003 respectively. The extract reduced acetic acid-induced nociception dose-depently. The extract (100, 200 and 400 mg/kg body weight) significantly (p < 0.05) reduced the number of writhings when compared with the control group. The percentage inhibition of the number of writhings for various doses of the extract were (42.11 %) (66.67 %) and 61.4. %) respectively. The extract inhibited phospholipase A2 activity, the absorbance values for different doses of the extract (1.0), (1.2), (1.4), (1.6) and (1.8 ml) were 0.035±0.002, 0.055±0.001, 0.042±0.002, 0.078±0.001, 0.017±0.000 and 0.056±0.001 respectively. The results showed that the extract at 100, 200 and 400 mg/kg body weights used in this study has potential anti-inflammatory and analgesic effects.