Evaluation of Analgesic Activities of Extracts of Two Marine Molluscs: var radula (Linnaeus) and (Müller).

Purpose And Methods: In this study, the analgesic activity of the crude alcohol (acetone-methanol) and aqueous (in PBS, pH 7.2) extracts of the marine molluscs, and has been evaluated using the formalin test (for chronic antinociceptive) and the tail-flick (acute antinociceptive) pain models in male swiss albino mice.

Results: The results show that the extracts of and demonstrated high safety margins as single doses of up to 2000 mg/kg bwt proved to be well tolerated and non-lethal, although the alcohol extract of caused necrosis in the liver and kidney when administered at a dose level of 2000 mg/kg bwt. In the formalin test, treatment with the aqueous extracts of and as well as the alcohol extract of 30 min before the subcutaneous injection of 5% formalin to the paw of the mice resulted in a significant time- and dose-dependent reduction in total and phase 2a pain-related behavior and thus nociception. The extracts had no analgesic effect in tail-flick test up to the highest dose tested.

Conclusion: Hence, the results from both models indicate that the site of their analgesic action is probably peripheral.