Archive for the ‘Ginger’ Category

Ginger: An Overview and Summary

Ginger is the rhizome or underground stem of the plant Zingiber officinale, and has been in use as a medicinal plant for millennia in Asia and the Middle East. The plant is typically 1 meter or so high, and the flowers grow directly from the rhizomes which are the fleshy stems of the plant. The leaves are narrow and are shiny green in color. The flowers are yellow in color with red to purplish tint on the edges. The rhizome, which is actually part of the stem of the plant, grows underground and is the primary source for the active components of the plant. The rhizomes appear fleshy, thick and rootlike, and cut portions of the rhizome are yellow in appearance.

Ginger has been used medicinally to treat nausea in pregnancy [1-2], motion sickness [3], arthritis [4], and may lower cholesterol [5]. In a recent meta-analysis, Borrelli et al [2] reviewed the results of 6 double-blinded placebo controlled studies of the efficacy of ginger in relieving the pregnancy-induced nausea. Overall, 4 of the trials found that ginger was more effective than placebo; two of the trials found that ginger was as effective as vitamin B6 in treating this condition. In a double-blinded, placebo controlled trial of 1 gm of daily ginger versus placebo, Grontved et al [3] found that naval cadets on the high seas reported significantly less symptoms of nausea and vomiting in the ginger-treated group as compared with placebo. Altman et al [4] found a significant reduction in pain with standing and with walking short distances in a group of osteoarthritis patients who received ginger extract versus placebo. Finally, Fuhrman et al [5] found that daily administration of 250 µg of ginger extract significantly reduced triglyceride and LDL cholesterol levels in mice.

The active components of ginger are numerous and diverse. In addition, there are substantial chemical differences between the fresh and dried forms of ginger rhizome [6]. The odor of ginger is predominantly derived from its volatile oil which comprises 1-3% of the rhizome. The pungency of the fresh herb is due to compounds known as gingerols; the most abundant of which is [6]-gingerol (1). Dried ginger pungency is derived from the shogaols which are formed from the gingerols during the drying and dehydration process. There is evidence that the [6]-gingerol species is responsible for the triglyceride lowering effects of ginger [7]. In addition, there is some evidence that the anti-nausea properties of ginger are due to anti-serotonergic effects of [6]-gingerol, [6]-shogaol and galanolactone [8-9].

 

 

References

1. White, B., Ginger: an overview. Am Fam Physician, 2007. 75(11): p. 1689-91.

2. Borrelli, F., R. Capasso, and A.A. Izzo, Effectiveness and safety of ginger in the treatment of pregnancy-induced nausea and vomiting – Reply. Obstetrics and Gynecology, 2005. 106(3): p. 640-641.

3. Grontved, A., et al., Ginger root against seasickness. A controlled trial on the open sea. Acta Otolaryngol, 1988. 105(1-2): p. 45-9.

4. Altman, R.D. and K.C. Marcussen, Effects of a ginger extract on knee pain in patients with osteoarthritis. Arthritis Rheum, 2001. 44(11): p. 2531-8.

5. Fuhrman, B., et al., Ginger extract consumption reduces plasma cholesterol, inhibits LDL oxidation and attenuates development of atherosclerosis in atherosclerotic, apolipoprotein E-deficient mice. J Nutr, 2000. 130(5): p. 1124-31.

6. Ali, B.H., et al., Some phytochemical, pharmacological and toxicological properties of ginger (Zingiber officinale Roscoe): a review of recent research. Food Chem Toxicol, 2008. 46(2): p. 409-20.

7. Kadnur, S.V. and R.K. Goyal, Beneficial effects of Zingiber officinale Roscoe on fructose induced hyperlipidemia and hyperinsulinemia in rats. Indian J Exp Biol, 2005. 43(12): p. 1161-4.

8. Huang, Q.R., et al., Anti-5-hydroxytryptamine3 effect of galanolactone, diterpenoid isolated from ginger. Chem Pharm Bull (Tokyo), 1991. 39(2): p. 397-9.

9. Yamahara, J., et al., Inhibition of cytotoxic drug-induced vomiting in suncus by a ginger constituent. J Ethnopharmacol, 1989. 27(3): p. 353-5.