Anti-inflammatory and antinociceptive effects of active ingredients in the essential oils from Gynura procumbens, a traditional medicine and a new and popular food material

Ethnopharmacological relevance Gynura procumbens is applied topically for the treatment of traumatic injuries in South China. Materials and methods This study was conducted to identify the active ingredients in the essential oils from Gynura procumbens (GPEO) by Gas Chromatography-Mass Spectrometer (GC–MS) and to elucidate the mechanisms underlying the anti-inflammatory and antinociceptive effects in vivo and in vitro. Results A reduction in dswelling and pain were observed in mice treated with GPEO or its active ingredients (α-pinene, 3-carene, and limonene) compared with mice treated with a solvent control. GPEO or its three active ingredients had potent pharmacological effects on COX-2 overexpression and LPS-induced migration of Raw264.7 macrophages. All three ingredients inhibited nociceptive stimulus-induced inflammatory infiltrates and COX-2 overexpression, which could be responsible for the anti-inflammatory effect of GPEO. However, only 3-carene produced an antinociceptive effect. Conclusion Consistent with the traditional usage in Southern China, GPEO may serve as a promising potent external therapeutic agent for the treatment of chronic pain.