GINGER
Botanical name: Zingiber officinalis
MAJOR CHEMICAL CONSTITUENTS
The major chemical constituents are volatile oils, including β-bisabolene and zingiberene, sesquiterpenes, including zingiberol, zingiberenol, the oleoresin shaogol, numerous monoterpene hydrocarbons, alcohols, and aldehydes, oleoresins, free fatty acids including palmitic acid, oleic acid, linoleic acid, caprylic acid, capric acid, lauric acid, myristic acid, steric acid, and starch and amino acids.
PRINCIPAL USES
TRADITIONAL AND HISTORICAL USES
Ginger has been used traditionally from Asia to the Caribbean for its antispasmodic, carminative, and diaphoretic properties. It has been used in traditional Chinese medicine (TCM), for example, since at least the ninth century for the treatment of nausea, diarrhea, and digestive complaints. Ginger was included in the United States Pharmacopoeia (USP) and the National Formulary as a carminative, stimulant, and aromatic herb. Because of geographic/climatic distribution of the herb, its use was not reported in northern European traditional herbalism, but its place in modern Western herbalism has become firmly established, as described in this profile.
CLINICAL INDICATIONS
Modern use of ginger has focused on its efficacy as an antiemetic for the treatment of nausea and vomiting in a variety of contexts, including during pregnancy and for patients undergoing chemotherapy. It has also been used for the treatment of appetite loss in cases of HIV, cancer, and the side effects of medications for their treatment. Herbal practitioners also widely use ginger for the treatment of gynecologic pain, including dysmenorrhea, pain associated with uterine fibroids, and chronic pelvic pain. It is also used for the treatment of premenstrual headaches and for the relief of diarrhea and cramping bowel pain that often accompanies dysmenorrhea, PMS, and endometriosis.
IN VITRO, ANIMAL, AND CLINICAL DATA
Ginger has been shown to have antiemetic effects in animal and human studies, possibly through an antiserotinergic effect. In seemingly contradictory animal studies, the herb has been shown to both increase stomach acid production, possibly interfering with the effects of antacid medications, and to significantly reduce gastric secretions and provide gastric mucosal protection with a reduction in gastric ulcers comparable to the effects provided by NSAIDs. At 62 mg/kg ginger extract has demonstrated protective effects against stress ulcer induction in rats, although to a lesser extent than cimetidine. The antiplatelet effects of ginger are also controversial. Although the herb does inhibit prostaglandin, thromboxane, and leukotriene synthesis, inhibition of platelet synthesis has been inconsistent among studies. Ginger has demonstrated anti-inflammatory activity in vitro, with COX-2 inhibition and resultant reductions of severe arthritis, paw and joint swelling in rats treated with ginger oil. Fresh ginger juice has a hypoglycemic effect in nondiabetic and diabetic rabbits and rats, with the effect more pronounced in diabetic animals.
MECHANISMS OF ACTION
The aromatic principles of ginger are considered responsible for its medicinal actions, including enzymatic inhibition of prostaglandin, thromboxane, and leukotriene synthesis. The mechanisms of action on nausea and vomiting remain uncertain, with studies demonstrating increased gastric motility contradictory to those showing no motility. Another theory is that the herb acts via a centrally mediated effect on 5-hydroxytryptamine-3 (5-HT3), an effect that has been demonstrated in vitro. There is some evidence that ginger increases stomach acid production, thus possibly interfering with antacid medications.
