Analgesic and anti-inflammatory potential of three new topical polyherbal formulations in wistar rats

The aim of this study was to evaluate the possible analgesic and anti-inflammatory effects of three new topical formulations; DRDC/AY/8037, DRDC/AY/8039 and DRDC/AY/8040. Activity was carried out on adult male wistar rats of 200-250 g each. Animals were divided into different groups, each group was indicated by the formulation used (DRDC/AY/8037, DRDC/AY/8039 and DRDC/AY/8040), control group for each study and two standards (diclofenac based and herbal based). Further, for both analgesic and anti-inflammatory activity, 300 mg of different formulations and standard were applied to the dorsal surface of the left hind paw by gently rubbing 50 times with the index finger to respective groups. Rats of the control group were applied with vehicle base. For evaluation of analgesic activity, twenty microliter of 5% formalin was injected subcutaneously into the hind paw of animals fifteen minutes after application of formulations. Five minutes later the time (in seconds) spent in licking and biting responses of the injected paw was taken as an indicator of pain response. For evaluation of anti-inflammatory activity, subplantar injection of 100 L of 1% freshly prepared solution of carrageenan was given for inducing paw edema, 30 min. after application of formulations. Percentage inhibition of paw edema (early and late phase) was recorded with reference to control and was regarded as a measure of anti-inflammatory activity. Results showed that formulations; DRDC/AY/8037, DRDC/AY/ 8039 and DRDC/AY/8040 showed 38.6%, 64.8% and 55.6% reduction in the pain response compared to control group as measured through reduction in paw edema. Results of analgesic activity of test formulations were comparable to the herbal based standards and better than diclofenac base marketed formulation. Results of anti-inflammatory activity showed that formulations DRDC/AY/8037, DRDC/AY/8039 and DRDC/AY/8040 showed 16.63%, 20.42% and 9.63% early phase paw edema inhibition and 38.35%, 45.54% and 45.85% late phase paw edema inhibition. These results supported analgesic and anti-inflammatory effects of test formulations and their use in local management of pain and inflammation.