Ginger (Zingiber officinale Roscoe) is a member of the Zingiberaceae family of plants. The plant is native to Asia but is now cultivated in the West Indies, Africa, India, and other tropical regions. The underground stem (rhizome) is used for preparation of ginger and can be obtained in colors varying from white to brown, depending on whether the exterior is scraped off and how it is initially treated. This rhizome can be processed into a powder, syrup, volatile oil, and oleoresin.
Its use in culinary applications dates as far back as the 13th century. Among all spices, it exhibits one of the greatest diversity of uses, such as in dietary supplements, beverages (such as ginger ales), and food products (such as in curry powder, confectionaries, soups, jams, and baked goods). It has been a part of healing strategies in Asia, India, Europe, and the Middle East for centuries for treatment of such disorders as arthritis, stomach upset, asthma, diabetes, and menstrual irregularities, to name a few
Medicinal species: Zingiber officinale.
Common names: Ginger, African ginger, Black ginger, Cochin ginger, Gan jiang, Gegibre, Ingwer, Jamaican ginger, Race ginger.
Botanical Family: Zingiberaceae. Ginger is closely related to two other cooking spices, turmeric and cardamom.
Plant description: Ginger is a 2 – 4 foot tall perennial with grass like leaves up to a foot in length. It is the underground root or rhizome that is used for culinary and medicinal purposes.
Where it’s grown: Indigenous to warm tropical climates, ginger is widely grown in Asia, Africa, India, Jamaica, Mexico, and Hawaii
Ginger as growth promoter
Ginger extracts have been reported to enhance the growth of teleosts. For instance, rainbow trouts (Oncorhynchus mykiss) that were fed ginger had significant increases in growth, feed conversion, and protein efficiency. Supplementing diets with acetone extract from ginger was reported to enhance the growth of tilapia (Oreochromis mossambicus) (Immanuel et al., 2009). The administration of ginger can produce significantly higher weight gain and specific growth rates in Penaeusmonodon post larvae (Venkataramalingam et al., 2007). The efficiency of feed proportionately increased with the increased percentage of ginger. Moreover, digestive enzyme activity significantly increased with ginger enrichment (Venkataramalingam et al., 2007)
Ginger, a natural dietary component, has been known to have antioxidant and anticarcinogenic properties demonstrated the chemopreventive efficacy of ginger in colon cancer. They had investigated the effect of ginger on the initiation and post-initiation stages of 1, 2- dimethyl hydrazine (DMH)-induced colon carcinogenesis in male Wistar rats. The number of tumours, as well as the incidence of cancer, was decreased significantly on treatment with ginger. Attributed the anticancer properties to the presence of pungent vallinoids, e.g. -gingerol and -paradol, shogaols, zingerone, etc.
Effects on the gastrointestinal tract
The active components of ginger is reported to stimulate digestion, absorption, relieve constipation and flatulence by increasing muscular activity in the digestive tract. The effectiveness of ginger (940 mg) in motion sickness was compared to that of dimenhydrinate (100 mg) in 18 male and 18 female college students, who were self-rated as having extreme or very high susceptibility to motion sickness. The study concluded that ginger was superior to dimenhydrinate in preventing motion sickness.
Ginger administration (1g) prior to elective gynaecologic laparoscopy was also found to be effective in preventing postoperative nausea and vomiting. The effect of ginger was similar to that observed with 100 mg metoclopramide. In addition, a double blind study in 27 pregnant women suffering from morning sickness demonstrated that oral administration of 250 mg of powdered ginger 4 times daily over 4 days significantly reduced symptoms of nausea and vomiting
Gingerols, which are the key ingredients responsible for the activity of ginger have shown important pharmacological effect. It is used to treat nausea after surgery and same has been proved in several randomized clinical trials. This effect is reported to be seen due to its action on the 5-HT3 receptor. Ginger is used for the treatment of headache and also have good effect on reducing symptoms of pain. This effect is believed to be due to reduction in prostaglandin synthesis. It has also been reported that ginger help to suppress leukotriene biosynthesis by inhibiting 5-lipoxyganse
Ginger contains pungent phenolic substances with pronounced antioxidative and anti-inflammatory activities. The antitumour – promoting activity of -gingerol, a major pungent principle, was investigated using a two-stage mouse skin carcinogenesis model.
Antiplatelet effect of gingerol isolated from Z.officinale. Gingerol (0.5–20 μM) concentration dependently inhibited the aggregation and release reaction of arachidonic acid and collagen-induced rabbit platelets, but not those induced by platelet activating factor U46619 and thrombin.
Antioxidant activity of ginger extract. Total phenols of the alcoholic ginger extract are about 870.1 mg/g dry extract. 2,2-Diphenyl-1-picril hydrazyl radical (DPPH) scavenging reached 90.1% and exceeded that of butylated hydroxyl toluene (BHT). The antioxidant activity in a linoleic acid/water emulsion system determined by means of thiobarbituric acid-reactive substances (TBARS) was highest at 37°C – 73.2 and 71.6% when the formation of conjugated dienes was inhibited. Ginger extract inhibited hydroxyl radicals by 79.6% at 37°C and 74.8% at 80°C, which showed a higher antioxidant activity than quercetin.
Ginger as an immunostimulant
In aquaculture, the application of dietary medicinal herbs as immunostimulants can elevate the innate defense mechanisms of fish against pathogens during periods of stress, such as, intensive farming practices, grading, sea transfer, vaccination and reproduction. The excess use of antibiotics in the management of disease in aquaculture has resulted in serious health and environmental problems. Consequently, the need of safe and effective alternatives to antibiotics is required. In this context, immunostimulants have attracted significant attention.
Ginger as a natural antibiotic is one of the most effective natural immunostimulants. The powdered ginger rhizome is able to enhance non-specific immune response in rainbow trouts (Haghighi and Rohan, 2013). Non-specific immunity plays an especially important role in the defense of fish and is the sole immunological mechanism by which invertebrates protect themselves from diseases (Secombes and Olivier, 1997).
Non-specific defense mechanism plays an important role in all stages of fish infection. Fish particularly depend mostly on these non-specific mechanisms than mammals do (Avtalion, 1981). Ginger essential oil showed improvement in humoral and cell mediated immune response in immunesuppressed mice (Carrasco, et al., 2009)
Blood circulation and anti-cramp effects
Ginger has been discovered to enhance blood circulation throughout the body by stimulating the heart muscles and by diluting circulating blood. This enhances cellular metabolism and aids to relieve certain conditions such as cramp and tension. The powerful anti-inflammatory action on prostaglandin synthesis also help in relieving menstrual cramps
Cholesterol regulation and hypotensive properties
Ginger extracts interferes with the biosynthesis of cholesterol, thereby leading to decreasing cholesterol levels in animals. Ginger extracts have antilipidemic effects, by reducing thermogenesis and high lipids levels. They also help to increase serum HDL-cholesterol. Ginger is very effective in lowering blood glucose level when taken in dried form. It also decreases triglyceride level. Long term usage has been reported to aid the increase of high-density lipoprotein cholesterol concentrations.
There is a study which proved the hypotensive effect of ginger when it was given at 0.3-3 mg/kg. It aids the reduction of atrial blood pressure by blocking calcium channel or by acting on muscarinic receptor. Studies have suggested that ginger may improve insulin sensitivity in body. The mineral elements contained in ginger makes it effective for this same purpose
Ginger has strong antibacterial and to some extent antifungal properties. In vitro studies have shown that active constituents of ginger inhibit multiplication of colon bacteria. These bacteria ferment undigested carbohydrates causing flatulence. This can be counteracted with ginger. It inhibits the growth of Escherichia coli, Proteus sp, Staphylococci, Streptococci and Salmonella.
The ginger extract has antimicrobial action at levels equivalent to 2000 mg/ ml of the spice. Ginger inhibits aspergillus, a fungus known for production of aflatoxin, a carcinogen . Fresh ginger juice showed inhibitory action against A.niger, S.cerevisiae, Mycoderma SPP. And L. acidophilus at 4, 10, 12 and 14% respectively at ambient temperatures