Pharmacognostic and Pharmacological Screening of Psidium guajava Stem Extract for its Analgesic Potential

Abstract

Context: The search for biologically active compounds from natural source has always been of great interest to researchers looking for new source of drugs useful in infectious diseases. Higher plants have played a vital role as the source of important therapeutic agents. Objective: The present investigation was aimed to find novel analgesic agent from herbal origin. For the purpose, Psidium guajava stem extracts was screened for its analgesic potential. Materials and Methods: Animal model of acetic acid induced writhing was followed. Three different extracts were used to study the activity. Results: The methanolic extract at the dose tested was shown to possess analgesic activity. The significant reduction in acetic acid-induced writhings suggests that the analgesic effect may be peripherally mediated via the inhibition of synthesis and release of prostaglandins (PGs) and other endogenous substances. Discussion: The abdominal constriction response induced by acetic acid is a sensitive procedure to evaluate peripherally acting analgesics. In general acetic acid causes pain by liberating endogenous substances such as serotonin, histamine, PGs bradykinins and substance P, which stimulate nerve endings. Local peritoneal receptors are postulated to be involved in the abdominal constrictions response. Conclusion: It can be concluded that the crude extract of stem of P. guajava have given positive results for analgesic activity. These medicinal herbs may afford lead compounds which could be beneficial for future drug development.