<i>Vitex polygama</i> extract and the flavonoid orientin alleviates vincristine-induced neuropathic pain in mice: possible role of muscarinic and opioid receptors and nitric oxide

Neuropathic pain affects 7-10% of the global population and is often poorly managed by current pharmacological treatments, which can cause significant adverse effects. This study evaluated the hydroalcoholic extract of <i>Vitex polygama</i> (VPE) and its flavonoid orientin in a vincristine-induced neuropathic pain model. Neuropathic pain was induced by vincristine and assessed using the hot plate test (for thermal hyperalgesia) and von Frey test (for mechanical allodynia). Atropine, naloxone, and L-NAME were used to investigate the mechanism of action of VPE. Antinociceptive effects of VPE were observed at a dose of 30 mg/kg, reversed by muscarinic and opioid receptor antagonists and a nitric oxide synthase inhibitor, indicating the involvement of multiple pathways. Orientin (30 mg/kg) also demonstrated novel antinociceptive activity, inhibited by atropine, indicating muscarinic receptor involvement. This study demonstrated the newsworthy antinociceptive activity of <i>V. polygam</i>a and its flavonoid orientin in a vincristine-induced neuropathic pain model.