Investigation on Central and Peripheral Analgesic and Anti-Inflammatory Activity of Punarnavasava, an Ayurvedic Preparation.

Aims: Punarnavasava (PNR) is an Ayurvedic formulation approved by the “National formulary of Ayurvedic Medicine 2011”, of Bangladesh. It is traditionally used in arthritic pain, lumbago and sciatia. Sparse scientific evidence is available to support the efficacy of this preparation. Hence, we planned to document scientific evidences of the pharmacological activity of this preparation. Study Design: Our present study aims to elucidate the probable anti-nociceptive and anti-inflammatory mechanisms of PNR. Place and Duration of the Study: The experiments were performed at the pharmacology lab of North South University during the period of October 2010 to July 2011. Methodology: Two thermal anti-nociceptive models were used, the hot-plate test and tail immersion test, to find out the possible role of the central nervous system in its action. Three in-vivo analgesic and anti-inflammatory models, carrageenan induced paw edema, acetic-acid writhing, and formalin induced paw lick tests, were carried out to test its potential anti-inflammatory and peripheral analgesic properties. Results: The dose dependent study of PNR (10mL/kg, 20mL/kg, and 40mL/kg) showed potential involvement of the CNS in anti-nociceptive activity of PNR. Carrageenan induced paw edema and acetic acid writhing tests both gave significant results (P=.05), indicating possible peripheral analgesic and anti-inflammatory action. Formalin induced paw-licking test (with and without naloxone co-administration), a differentiator of nurogenic pain (CNS modulated) and inflammatory pain (peripheral nociception), showed that PNR had significant effect in suppressing inflammatory pain (P=.05) but not neurogenic pain. Conclusion: Compiling the results of the experiments, it can be reported that Punarnavasava has both central and peripheral analgesic and anti-inflammatory action.