Anti-inflammatory and Analgesic Activities of Topical Formulations of Pterocarpus Santalinus Powder in Rat Model of Chronic Inflammation.

INTRODUCTION: The incidence of arthritis is quite high and there is a need for the search of natural products to halt the progression of disease or provide symptomatic relief without significant adverse effects.

AIM: This study aimed at evaluating the anti-inflammatory and analgesic activities of topical Pterocarpus santalinus in an animal model of chronic inflammation.

MATERIALS AND METHODS: Albino rats of either sex were divided into five groups of six rats each (Group I - Control, Group II -Gel base, Group III -P. santalinus paste, Group IV -P. santalinus gel, Group V- Diclofenac gel). Chronic inflammation was induced on day 0 by injecting 0.1 ml Complete Freund's Adjuvant (CFA) in sub-plantar tissue of left hind paw of the rats. Topical treatment was started from day 12 till day 28. Body weight and paw volume (Plethysmometer) were assessed on day 0, 12 and 28. Pain assessment was done using Randall and Selitto paw withdrawal method. Data was analysed using GraphPad Prism version 5. Unpaired students t-test and ANOVA followed by Tukey's test was used for comparison among groups.

RESULTS: Only topical P.santalinus gel significantly reduced the body weight (p=0.02) due to reduction in inflammatory oedema of the left limb. P. santalinus gel also showed significant reduction (p=0.03) in paw volume of rats compared to the other groups. There was significant reduction in pain threshold (gm/sec) due to chronic inflammation, with all the study drugs (p<0.05) but with P. santalinus gel, this reduction was less (p<0.001).

CONCLUSION: Gel showed significant anti-inflammatory and mild analgesic activity on topical application in rat model of chronic inflammation.