THE ANALGESIC PROPERTIES OF THE FLAVONOID GALANGIN IN EXPERIMENTAL ANIMAL MODELS OF NOCICEPTION

Abstract

This study aimed to investigate the antinociceptive properties of galangin using various nociception models. Galangin's effects were assessed across different doses (50, 100, 150, and 200 µg/kg bw) in mice through multiple pain tests. The results were compared to those of mice treated with acetylsalicylic acid or morphine, with or without naloxone. In addition to standard pain models, capsaicin-and glutamate-induced tests were employed to explore the involvement of the vanilloid and glutamatergic systems in galangin's pain-relief mechanisms. It was found that galangin exhibited a significant, dose-dependent reduction in pain behaviour during the acetic acid-induced writhing test, with a 72.2% inhibition observed at a 200 µg/kg bw dose. In the hot plate test, it increased latency period, with a 72.0% increase at the same dose. Galangin also significantly inhibited both neurogenic and inflammatory phases in the formalin-induced paw-licking test. These effects were reversed by naloxone treatment, indicating opioid system involvement. Galangin further showed inhibitory effects on neurogenic nociception induced by capsaicin and glutamate. Enzyme-linked immunosorbent assay (ELISA) revealed that galangin, at doses of 100 and 200 µg/kg bw, significantly reduced pro-inflammatory cytokine levels (IL-1β, TNF-α, IFN-γ, and NO) in mouse serum. The study concluded that galangin possesses antinociceptive activity mediated through central and peripheral pathways, modulating vanilloid receptors, opioid receptors