Medicinal plants as antiemetics in the treatment of cancer: a review.

Chemotherapy- and radiotherapy-induced nausea and vomiting are the most common, intractable and unpleasant side effects in patients undergoing treatment for cancer. 5-Hydroxytryptamine-3 (5-HT3) receptor antagonists plus dexamethasone have significantly improved the control of acute nausea and vomiting, but delayed nausea and vomiting remains a significant clinical problem. Combined neurokinin-1 receptor antagonists with 5-HT3 antagonists and steroids are observed to be better in the control of both acute and delayed emesis. However, the use of these antiemetics is observed to possess inherent side effects. The medicinal plants such as Scutellaria baicalensis, Korean red ginseng, American ginseng berry, Ganoderma lucidum, Zingiber officinale, grape seed extract, and the oil of Mentha spicata are reported to be effective in the treatment of nausea and vomiting mostly in preclinical studies. Of these, ginger has also been evaluated for its efficacy in humans and the results have been contradictory. The current review for the first time summarizes the results related to these properties. An attempt is also made to address the lacunae in these published studies and to emphasize aspects that need further investigations for these plants to be of use in clinics in the future.