Ginger: Zingiber officinale Roscoe

Plant

Ginger is a perennial plant native to southeastern Asia and is now cultivatd in other tropical regions such as South America, China, India, Africa, Jamaica, the Caribean, and parts of the United States. The spicy sweet, knotty underground stems (Rhizomes Zingiberis) are highly treasured in cookin and in medicine. The plant produced spikes of green-purple flowers. Scientific name is Zingiber officinale Roscoe and occasionally other species (Peirce, 1999; Skidmore-Roth, 2001). Icelandic names are called such as engifer, engiferjurt or engiferplanta. Common names in english are Africa ginger, black ginger, Canton ginger, Cochin ginger (Asian), Common ginger, Garden ginger, Gingembre, Imber, Jamaican ginger, race ginger (Peirce, 1999; Skidmore-Roth, 2001). Ginger is not found in the wild, its origins are uncertain. It is likely to have originated from India as ginger plants there show the most biological variability (P. N. Ravindran, 2005).

The rhizome is horizontal, branched, fleshy, aromatic, white or yellowish to brown. Stem is leafy, thick, to 60 cm high. Leaves are pointed, narrowly or linear-lanceolate, approx 20 cm long and 1.5-2 cm wide, clasping the stem by long sheaths. The in-florescences, rarely produced by cultivated plants, are separate, approx 20 cm high. Corolla has two yellow-green, pointed segments and shorter, an ablongovate, dark-purple lip spotted and striped with yellow. Each flower has only one shortstalked, fertile stamen and solitary stigma. The fruit, which is rarely formed, is a dehiscent capsule containing relatively large (Ross, 2005). It is cultivated in the tropics for its edible rhizome at approximately 10 months of age (Portnoi et al., 2003).

History

Ginger is one of the most important an most widely used spices wordwide. In ancient times ginger was more valued for its medicinal properties and played an important role in primary heath care in ancient India and China.

            Zingiber was derived from ingiver, meaning ginger rhizome. The term ingiver spread to ancient Greece and Rome through the Arab traders, and from there to Western Europe. The present-day names for ginger in most of the Western languages were derived from.

Ginger was one of the most commonly traded spices during the 13th and 14th centuries. Arabs carried the rhizomes on their voyages to East Africa to plant at coastal settlements and on Zanzibar. During this time in England, ginger was sought after, and one pound in weight of ginger was equivalent to the cost of a sheep (P. N. Ravindran, 2005).

Use

The therapeutic effects of ginger can be traced back to 2000 BCE in the Vedic literature of India (Mishra et al., 1994). it is used to treat  nausea, and related stomach problems (Mishra et al., 1994), headaches, colds (Yoshikawa et al., 1994), gassy indigestion, bloating, and cramping, calm inflammation and rheumatic pains, treat kidney ailments, soothe sore throats, and ease other cold symptoms such as cough. A number also consider it potentially valuable for preventing liver damage and treating peptic ulcers, impotence, rheumatic disorders, and depression (Peirce, 1999).

Ginger is a herb of Far Eastern traditional medicine. The rhizome (underground stem) is used as a spice and also as a medicine. It can be used fresh, dried and powdered, or as a juice or oil. Other uses include treating baldness, malaria, orchitis, poisonous snake bites, rheumatism, migraine headache, and toothaches. Dried ginger is used for chest pain, low back pain, and stomach pain. Some people pour the fresh juice on their skin to treat burns (Do Tat Loi Dr., 1982). Traditionally used to treat various types of “stomach problems” including motion sickness (travel sickness), morning sickness, upset stomach, gas, diarrhea, post-surgery nausea as well as nausea caused by motion, chemotherapy in cancer, and pregnancy, dyspepsia, lack of appetite, anorexia, colic, bronchitis, and rheumatic complaints (The Review of Natural Products. Ginger, July, 2004). Ginger is also used for rheumatoid arthritis, osteoarthritis, and joint and muscle pain (Herbsataglance. Ginger. National center for complementary alternative medicine (NCCAM), May, 2008; Peirce, 1999).

In addition ginger is known such as a herb has been used in treatment as antiemetic, cardiotonic, antithrombotic, antibacterial, antioxidant, antitussive, antihepatotoxic, anti-inflamamtory, antimutagenic, stimulant, diaphoretic, diurectic, spasmolytic, immunostimulant, carminative, and cholagogue actions (The Review of Natural Products. Ginger, July, 2004).

There is some evidence in laboratory studies to suggest that components in ginger may have anticancer activity, help to combat skin, ovarian, colon and breast cancer (Lee et al., 2008). More research is needed to determine the effects of ginger on various cancers in humans. Ginger is also indicated in treatment for diabetic, cardio-vascular disease, preliminary studies suggest that ginger may lower blood cholesterol, glucose levels and blood pressure (Barnes et al., 2007). Each of these effects may protect the blood vessels from blockage and the damaging effects of blockage such as atherosclerosis, which can lead to a heart attack or stroke.

Marketing

The underground sterms of ginger plant are used in cooking, baking and for heath purpose. Common forms of ginger include fresh or dried root, tablets, capsules, liquid extract (tinctures), powder,  teas and decoction (Skidmore-Roth, 2001).

Chemical components

- Volatile oils (1-3%). Complex, predominately hydrocarbons. β-Bisabolene and Zingiberene, other sesquiterpenes include zingiberol, zingiberenol, ar-curcumene, β-sesquiphellandrene, β-sesquiphellandrol (cis and trans).

- Carbohydrates is major constituent, up to 50%

- Lipides (6-8%). Free fatty acids (e.g. palmitic, oleic, lonoleic,...); tryglycerides, phosphatidic acid, lecithins.

- Oleo-resin The characteristic odor and flavor of ginger root is caused by a mixture of Zingerone, Shogaols and Gingerols, volatile oils. Gingerol homologues (33%) including derivatives with a methyl  side chain. Shogaol and zingerone are dehydration products of gingerols, 1-dehydrogingerdione, 6-gingesulfonic acid and volatile oils.  

- Other constituents: Amino acids, protein (9%), vitamins (niacin B3, A), minerals (magnessium, potassium, copper, manganese) (Barnes et al., 2007).

The important active components of ginger root are thought to be volatile oil and pungent phenol compounds such as Zingerone, Shogaols and Gingerols. [6]-gingerol and  [6]-shogaol are main components that have pharmacological actions (Barnes et al., 2007; Newall et al., 1996).

           

Primary chemical components of ginger and their possible actions

Chemical class	Individual component	Possible action
Pungent phenol	Gingerol Zingerone Shogaol	Antioxidant, antiulcer, antiemetic, antioxidant, antiplatelet, anticancer Anti-inflammation, hypotension, hypoglycemia, hypocholesterolemia
Volatile oil	Bisabolene Zingiberene Zingiberol	Antimicrobe, antivirus
Proteolytic enzyme Gingesulphonic acid Sesquiterpene		Antiulcer Antivirus

(Barnes et al., 2007; Skidmore-Roth, 2001).

-          Chemical structures of gingerol, C₁₇H₂₆O₄, 294,38 g/mol

 and shogaol, C₁₇H₂₄O₃, 276,37 g/mol.

Chemical analysis shows that shogaols, a dehydrated product of gingerol, are responsible for ginger’s pungency (Lawless, 1995). Compounds of shogaol such as [4]-, [6]-, [8]- og [10]-shogaol have been found in ginger. The fresh rhizome contains very small amounts of shogaol, while the dried rhizome is rich in. This suggests that shogaols are formed through dehydration during processing or storage of the fersh rhizome. It seems that the amounts of [6]-gingerol and [6]-shogaol are effected by processing of the rhizome (Mazza and Oomah, 2000).

With gingerols as the major active components responsible for the pharmacological effects (Jolad et al., 2005).

           

Effect

Nausea and vomiting

 The mechanism by which ginger reduces nausea and vomiting might be due to the 6-gingerol constituent. It was once thought that ginger might work by increasing gastrointestinal (GI) motility, but more recent evidence shows that ginger does not influence GI emptying time (Phillips et al., 1993a). Other ginger constituents such as 6-shogaol and galanolactone seem to act on serotonin receptors. Galanolactone seems to act primarily on 5-HT3 receptors in the ileum, which are the same receptors affected by some prescription antiemetics such as ondansetron (Zofran). The predominant antiemetic action of ginger is localized in the GI tract, but there is some evidence that ginger constituents may also have central nervous system (CNS) activity (Lumb, 1993).

Nausea in pregnancy

Safe and effective relief of nausea and vomiting during prenancy. Ginger's anti-vomiting action has been shown to be very useful in reducing the nausea and vomiting of pregnancy, even the most severe form, hyperemesis gravidum, a condition which usually requires hospitalization (Fischer-Rasmussen et al., 1991). In one double-blind trial, each woman swallowed capsules containing either 250 mg ginger or lactose four times a day. During the first 4 days of the treatment period, ginger root brought about a significant reduction in both the severity of nausea and number of attacks of vomiting in 19 of 27 women in early pregnancy (less than 20 weeks). Unlike anti-vomiting drugs, which can cause severe birth defects, ginger is extremely safe, and only a small dose is required (Fischer-Rasmussen et al., 1991).

A review of six double-blind, randomized controlled trials with a total of 675 participants has concluded that ginger is effective in relieving the severity of nausea and vomiting during pregnancy. The review also concluded that side effects or adverse effects on pregnancy outcomes are rare (Borrelli et al., 2005).

Pregnant women with severe hyperemesis gravidarum are participants in the Motherisk Program in prospective comparative study who were taking ginger during the first trimester of pregnancy were enrolled in the study (Portnoi et al., 2003). The women were compared with a group of women who were exposed to nonteratogenic drugs that were not antiemetic medications. Various types of ginger were consumed by the women, including capsules, ginger tea, fresh ginger, pickled ginger, ginger cookies, ginger candy, inhaled powdered ginger, ginger crystals, and sugared ginger. A total of 49% of the women used capsules, with the rest using the various other preparations The women were followed up to ascertain the outcome of the pregnancy and the health of their infants. They were also asked on a scale of 0 to10 how effective the ginger was for their symptoms of NVP. There were no statistical differences in the outcomes between the ginger group and the comparison group with the exception of more infants weighing less than 2500 g in the comparison group . There were a total of 66 completed effectiveness scores with the mean score of 3.3 ± 2.9 SD. the capsules were significantly more effective than all the other preparations combined. However, almost half the women thought that the ginger was totally ineffective in alleviating their symptoms.

In double blind randomized controlled trial study the efficacy of ginger and dimenhydrinate in the treatment of nausea and vomiting in pregnancy (Pongrojpaw et al., 2007). The patients in group A received one capsule of ginger 500 mg twice daily while the patients in group B received the identical capsule of 50 mg dimenhydrinate twice daily. Ginger is as effective as dimenhydrinate in the treatment of nausea and vomiting during pregnancy and has fewer side effects.

Motion sickness (nausea caused by motion, travel sickness = ógleði vegna ferðaveiki)

Ginger has long been used as an alternative medication to prevent motion sickness. The mechanism of its action is known such as effects on vection-induced gastric dysrhythmias and vection-induced elevation of plasma vasopressin (Lien et al., 2003). In study effects of ginger on motion sickness and gastric slow-wave dysrhythmias induced by circular vection, reseachers hypothesized that ginger ameliorates the nausea associated with motion sickness by preventing the development of gastric dysrhythmias and the elevation of plasma vasopressin. Ginger effectively reduces nausea, tachygastric activity, and vasopressin release induced by circular vection. In this manner, ginger may act as a novel agent in the prevention and treatment of motion sickness (Lien et al., 2003).

Nausea after surgery

Research has produced mixed results regarding the use of ginger in the treatment of nausea and vomiting following surgery (postoperative nausea and vomiting (PONV)). Taking ginger 1 gram one hour prior to surgery seems to reduce the incidence of 24-hour postoperative nausea and vomiting (PONV) (Phillips et al., 1993b). One analysis suggests that ginger can reduce PONV by up to 38% (Chaiyakunapruk et al., 2006). Some evidence also suggests that ginger might be comparable to metoclopramide (Reglan) for reducing PONV (Phillips et al., 1993b). But ginger does not seem to reduce the incidence of 3-hour PONV (Arfeen et al., 1995). Ginger also might not be beneficial for reducing incidence of PONV in patients who have a history of a low rate of PONV (Visalyaputra et al., 1998).

Nausea due to chemotherapy in cancer

There is contradictory evidence about the effectiveness of ginger for chemotherapy-induced nausea and vomiting. Some evidence suggests that taking ginger orally might help reduce chemotherapy-induced nausea when given following administration of intravenous (IV) prochlorperazine (Compazine) (Ernst and Pittler, 2000). Other evidence suggests that giving ginger 1 gram/day for 5 days starting on the first day of cisplatin chemotherapy in combination with standard therapy is no more effective than standard therapy alone (Manusirivithaya et al., 2004).

Inflammatory

Ginger is sometimes used for inflammatory conditions such as rheumatoid arthritis (RA) (Srivastava and Mustafa, 1989). Some researchers speculate that certain constituents of ginger 8-paradol and 8-shogaol might inhibit cyclooxygenase (COX) and lipoxygenase pathways (Srivastava and Mustafa, 1989).

It also seems to inhibit the synthesis of prostaglandin-E2 (PGE2) and thromboxane B2 (TXB2), which mediate inflammation (Thomson et al., 2002).

             

Osteoarthritis

There is preliminary evidence that ginger might have modest benefits in osteoarthritis. One study shows that taking an extract of selected Chinese ginger (Eurovita Extract 33, EV.ext-33) with a standardized content of hydroxy-methoxy-phenyl compounds (HMP) was used (Institute of Drug Analysis. Data on file) (Bliddal et al., 2000). This extract was formulated in soft gelatine capsules which shields the content of ginger, orally 170 mg three times daily for 3 weeks is significantly less effective than ibuprofen 400 mg three times daily for reducing pain. Compared to placebo the ginger extract provided very modest to no significant reduction in pain (Bliddal et al., 2000).

Antioxidant  activity

Antioxidant effects. A study in mice, [6]-gingerol inhibits nitric oxide synthesis suggests that at least one reason for ginger's beneficial effects is the free radical protection afforded by one of its active phenolic constituents, 6-gingerol. In this in vitro (test tube) study, 6-gingerol was shown to significantly inhibit the production of nitric oxide, a highly reactive nitrogen molecule that quickly forms a very damaging free radical called peroxynitrite (Ippoushi et al., 2003). Another study found that in mice, five days treatment with ginger (10 mg per kilogram of body weight) prior to exposure to radiation not only prevented an increase in free radical damage to lipids (fats found in numerous bodily components from cell membranes to cholesterol), but also greatly lessened depletion of the animals' stores of glutathione, one of the body's most important internally produced antioxidants (Jagetia et al., 2003).

Anticancer activity

Extract or constituents of ginger in pungent such as gingerol, shogaol and zingerone see chemical components table. These phenolic substances have been found to possess many interesting pharmacological and physiological activities (Surh et al., 1998). Extracts of ginger have been shown to have cancer chemopreventive and cytotoxic or cytostatic activity in vitro and in vivo in animals. Extract of fresh ginger inhibited also 12-o-tetradecanoylphorbol-13-acetate (TPA)-induced skin tumor in a mouse skin tumorigenesis, epidermal oedema and hyperplasia. In vitro 6-gingerol resulted in inhibitory effects on cell viability and DNA synthesis in human promyelocytic leukaemia (HL-60) cells (Barnes et al., 2007). Ginger extract-HAPC (100 microg/ml) significantly it may also inhibit tumor necrosis factor (TNF)-alpha (Frondoza et al., 2004).

Protection against colorectal cancer. Gingerols, the main active components in ginger and the ones responsible for its distinctive flavor, may also inhibit the growth of human colorectal cancer cells, suggests research presented at the Frontiers in Cancer Prevention Research, a major meeting of cancer experts that took place in Phoenix, AZ, October 26-30, 2003 (Bode and Dong, 2003). In this study, researchers from the University of Minnesota's Hormel Institute fed mice specially bred to lack an immune system a half milligram of -gingerol three times a week before and after injecting human colorectal cancer cells into their flanks. Control mice received no -gingerol. Tumors first appeared 15 days after the mice were injected, but only 4 tumors were found in the group of -gingerol-treated mice compared to 13 in the control mice, plus the tumors in the -gingerol group were smaller on average. Even by day 38, one mouse in the -gingerol group still had no measurable tumors. By day 49, all the control mice had been euthanized since their tumors had grown to one cubic centimeter (0.06 cubic inch), while tumors in 12 of the -gingerol treated mice still averaged 0.5 cubic centimeter-half the maximum tumor size allowed before euthanization. Research associate professor Ann Bode noted, "These results strongly suggest that ginger compounds may be effective chemopreventive and/or chemotherapeutic agents for colorectal carcinomas (Bode and Dong, 2003).

Yagihashi said that [6]-Gingerol suppressed the reactive oxygen species-potentiated invasive capacity by simultaneously treating AH109A cells with [6]-gingerol, HX and XO or with [6]-gingerol and hydrogen peroxide. Furthermore, [6]-gingerol reduced the intracellular peroxide levels in AH109A cells. These results suggest that the suppression of hepatoma cell proliferation by [6]-gingerol may be due to cell cycle arrest and apoptosis induction. They also suggest that the anti-oxidative property of [6]-gingerol may be involved in its anti-invasive activity of hepatoma cells (Yagihashi et al., 2008).

Diabetic and cardio-vascular diseases

There is preliminary evidence that ginger may also have hypoglycemic, hypocholesterolemic, anthelmintic, gastroprotective, and antiplatelet effects. In laboratory models of diabetes, ginger seems to increase the release of insulin and lower cholesterol levels (Akhani et al., 2004).

Fresh ginger extract seems to have blood pressure-lowering effects, according to preliminary research. It seems to have calcium-channel blocking activity. It also has negative inotropic and chronotropic effects (Ghayur and Gilani, 2005).

Infective effects

Ginger exerts in vitro antioxidative, antitumorigenic and immunomodulatory effects and is an effective antimicrobial and antiviral agent (Chrubasik et al., 2005).

Summary: today, medicinal ginger is used mainly for prevention and treatment of the symptoms of nausea and voimiting associated with motion sicknes (travel sickness), pregnancy, post-surgery and cancer chemotherapy. It is also used as support in inflammatory conditions such as arthritis, and may even be used in antioxidant, diabetes, heart disease, cancer or in infective effects.

General dose

Fresh ginger 3-10 grams, or 2-4 grams of dry ginger, are taken daily for motion sickness, 1 gram of dried powdered ginger root 30 minutes to 4 hours before travel has been used; one to two more 500 mg capsules are taken as needed. As a digestive aid, 2 teaspoons powdered or grated root per cup water, or three 535 mg root capsules, three times a day (Peirce, 1999).

A higher dose of 650 mg 3 times daily has also been used (Chaiyakunapruk et al., 2006). For osteoarthritis, several different ginger extract products have been used. One ginger extract 170 mg three times daily has been used (Wigler et al., 2003). For postoperative nausea and vomiting, 1-2 grams powdered ginger root one hour before induction of anesthesia has been used (Chaiyakunapruk et al., 2006). For migraine headache, ginger 500 mg at the onset and repeated every 4 hours up to 1.5-2 grams per day for 3-4 days has been used (Grøntved and Hentzer, 1986).

Adverse reactions/ side effects

Orally, ginger is usually well tolerated when used in typical doses 1-2 grams of dried powdered ginger root. However, higher doses of 5 grams per day increase the risk of side effects and decrease tolerability (Srivastava and Mustafa, 1989). Common side effects most often reported are abdominal discomfort, gas, bloating, heartburn, nausea, vomiting, Anorexia, diarrhea, and a pepper-like irritant effect in the mouth and throat (Grøntved et al., 1988). Some people report experiencing some sedation or drowsiness. Topically, ginger can cause dermatitis in sensitive individuals, hypersensitivity reactions (Kanerva et al., 1996).

Interactions

Interactions with herbs and supplements: Using ginger along with herbs that might slow blood clotting could increase the risk of bleeding in some people. These herbs include angelica, clove, danshen, garlic, ginkgo, Panax ginseng, red clover, turmeric, and others (Thomson et al., 2002).

Interactions with drugs. All oral medications. Ginger may increase absorption of all medications taken orally. Anticoagulants/antiplatelets (ardeparin, anisindione, aspirin, dicumerol, dalteparin, heparin, warfarin). Ginger may increase the risk of bleeding when used concurrently with anticoagulants, ginger is thought to inhibit thromboxane synthetase and decrease in platelet aggregation. Ginger may increase plasma partial prothrombin time (PTT) in clients taking warfarin concurrently and may increase prothrombin time (PT) (Skidmore-Roth, 2001). Excessive doses of ginger can interfere with bleeding conditions and increase risk of bleeding. Excessive doses of ginger can cause hypoglycemia, necessitating a change in dose of diabetes medication (Akhani et al., 2004). Theoretically, excessive doses of ginger might worsen some heart conditions. Preliminary research suggests it has negative inotopic and chronotropic activity (Ciocon et al., 2004).

Toxicity

Large overdoses may induce CNS depression and may interfere with cardiac function, cardiotonic and cardiodepresant activity. Inhibition of platelet of aggregation, anticoagulant (The Review of Natural Products. Ginger, July, 2004). There is more some concern due to preliminary evidence that ginger might affect fetal hormones. Ginger in preventing nausea and vomiting of pregnancy; a caveat due to its thromboxane synthetase activity and effect on testosterone binding. However, studies in pregnancy women suggest that ginger can be used safely for morning sickness without harm to the fetus. The risk for major malformations in infants of women taking ginger does not appear. (Backon, 1991).

Contraindications

Pregnancy due to its emmenagogue and abortifacient effect (empirical) when taken in large amounts, ginger should not be used during pregnancy and lactation. It should not be used by persons with hypersensitivity to it. Gallstones unless a physician is consulted beforehand due to its cholagogue effect. Ginger should not be used by persons with cholelithiasis (Skidmore-Roth, 2001).

Summary  

Ginger is a perennial plant native to southeastern Asia. It is used to treat anti-emetic, anti-inflammatory, anti-oxidant, antiseptic, antispasmodic, anti-microbial, anti-viral, carminative, circulation. At present ginger has been used to alleviate post-surgery nausea as well as well nausea caused by motion, chemotherapy, and pregnancy. Ginger is also used for rheumatoid arthritis, osteoarthritis, and joint and muscle pain.

There is some evidence in laboratory studies to suggest that components in ginger may have anticancer activity, help to combat skin, ovarian, colon and breast cancer. More research is needed to determine the effects of ginger on various cancers in humans. Ginger is also indicated in treatment for diabetic, cardio-vascular disease, preliminary studies suggest that ginger may lower blood cholesterol, glucose levels and blood pressure.

Common forms of ginger include fresh or dried root, tablets, capsules, liquid extract (tinctures), powder,  teas and decoction. Orally, ginger is usually well tolerated when used in typical doses 1-2 grams of dried powdered ginger root.

            Side effects of ginger are rarely, but common side effects most often reported are abdominal discomfort, gas, bloating, heartburn, nausea, vomiting, Anorexia, diarrhea, and a pepper-like irritant effect in the mouth and throat Some people report experiencing some sedation or drowsiness. Topically, ginger can cause dermatitis in sensitive individuals, hypersensitivity reactions. However, higher doses of 5 grams per day increase the risk of side effects and decrease tolerability.

            Some contraindications of ginger in during pregnancy and lactation, persons with hypersensitivity to it and gallstones due to its cholagogue effect.

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