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Ginger has been recommended to combat nausea associated with chemotherapy. Gingerol was reported to reduce cisplatin (a platinum based  chemotherapy drug)-induced emesis in a vomiting model of mink possibly by inhibiting  the central or peripheral increase of 5-hydroxytryptamine, dopamine, and substance P. In contrast, addition of ginger root powder (1 g/day) to a standard antiemetic regimen with  metoclopramide had no advantage in reducing nausea or vomiting in acute or delayed phases of  cisplatin-  induced emesis in gynecologic cancer patients. Cisplatin can  cause renal oxidative and nitrosative stress and dysfunction. However, rats that were administered  cisplatin and [6]-gingerol exhibited lower lipid peroxidation and conservation of GSH coupled with  enhanced superoxide dismutase and catalase, which resulted in a restoration of normal renal function. Complementary intervention with ginger has also been suggested to have  possible benefits in preventing acute chemotherapy-induced nausea and vomiting (CINV) in children.

However, the results of a randomized, double-blind, placebo-controlled  trial indicated that ginger did not provide any additional benefit in reducing CINV when given with  a 5-hydroxytryptamine 3 (HT3) receptor antagonist and/or aprepitant (a substance P antagonist). Notably, compared with a normal diet, high-protein meals with ginger consumed  twice daily were reported to reduce the delayed nausea of chemotherapy and decrease the use of  antiemetic medications.

Nausea and vomiting during pregnancy affects most pregnant women, and over the years ginger  has been used to try to alleviate the condition . At least one survey indicated that  the overall use of dietary supplements in pregnant women appears to be low, but ginger is commonly  recommended and used to prevent nausea. Several  double-blind, randomized, placebo-controlled clinical trials have indicated that ginger consumption  is effective and safe in helping to prevent nausea and vomiting during pregnancy. Randomized trials suggest that although ginger  might not be as potent as some treatments, its consumption for treating  nausea or vomiting or both in early pregnancy has very few or no adverse side effects and seems  to be effective . In fact, ginger has been reported to be as effective  as dimenhydrinate (i.e., Dramamine) in treating nausea and vomiting in pregnancy with fewer side  effects. Women who received ginger (250-mg  capsules) appeared to experience less vomiting and nausea compared to those receiving placebo , and ginger also relieved pain from primary dysmenorrhea. The effectiveness of ginger has been compared with that of vitamin B6  (another recommended therapy) in randomized, double-blind, controlled trials.

Results indicated  that ginger and vitamin B6 therapy were equally effective in reducing nausea and the number of  vomiting episodes during pregnancy. In a  later randomized, double-blind, controlled trial, pregnant women were randomly divided to receive  either 650 mg of ginger or 25 mg of vitamin B6 (3xd/4 days). In this case, ginger actually appeared  to be more effective than vitamin B6, with only minor side effects. These results were supported in an additional trial in which pregnant women  with nausea were randomized into groups to receive either 1 g of ginger/day or 40 mg of vitamin  B6/day for 4 days. Results of this trial indicated that compared with a baseline, nausea and vomiting  in the ginger group were significantly less than those reported by the vitamin B6 group. A systematic review of the results of other double-blind, randomized, controlled  trials, uncontrolled trials, case reports, and observational studies indicated that ginger is superior  to placebo and as effective as vitamin B6 in relieving the severity of nausea and vomiting, with no  reported side effects or adverse effects on pregnancy. A similar review of the  literature regarding the safety and efficacy of ginger in the management of nausea and vomiting  during pregnancy revealed that ginger appears to be a relatively low-risk and effective treatment  for these symptoms. Importantly, no differences in birth weight, gestational  age, or frequencies of congenital abnormalities have been observed between ginger-treated  and untreated mothers. A survey of a group of obstetricians  and gynecologists revealed that most of them would recommend taking an antiemetic (71.3%), and  specifically ginger (51.8%), to patients suffering from moderate to severe nausea.

The most common and well-established use of ginger throughout history is probably its utilization in alleviating symptoms of nausea and vomiting. The benefits and dangers of herbal treatment of liver and gastrointestinal distress have been reviewed, and several controlled studies have reported that ginger is generally effective as an antiemetic. The effectiveness of ginger as an antiemetic has been attributed to its carminative effect, which helps to break up and expel intestinal gas. This idea was supported by the results of a randomized, double-blind trial in which healthy volunteers reported that ginger effectively accelerated gastric emptying and stimulated antral contractions. Previously, [6]-gingesulfonic acid, isolated from ginger root, was showed to be effective against HCl/ethanol-induced gastric lesions in rats. This compound showed weaker pungency but more potent antiulcer activity than [6]-gingerol or [6]-shogaol.

Ginger root is commonly recommended for preventing seasickness and is found to be superior to dimenhydrinate (Dramamine) or placebo against symptoms of motion sickness. A follow-up study also indicated that 1 g of ginger might be effective in reducing the subjective severity of seasickness in naval cadets on the high seas. On the other hand, additional research studies showed no benefits of using ginger for treating motion sickness, and at least one group reported that patients receiving ginger extract for treating osteoarthritis experienced more, although mild, gastrointestinal adverse events compared to a placebo-treated group. The exact antiemetic mechanism of ginger is not clear, although some evidence suggests that it inhibits serotonin receptors and exerts its antiemetic effects directly on the gastrointestinal system and in the central nervous system. Although the antiemetic effects of ginger are the most well-studied effects of this condiment and have been reviewed extensively, the effectiveness and safety of ginger for treating nausea and vomiting have been questioned in the past because the findings reported were often contradictory. At the same time, ginger continues to be recommended for alleviating nausea and vomiting associated with pregnancy, chemotherapy, and certain surgical procedures.

Ginger has been suggested to be effective against inflammation, osteoarthritis, and rheumatism. However, inconsistencies in clinical studies have led to debate regarding the effectiveness and safety of ginger for treatment of arthritis. An earlier study showed that ginger oil (33 mg/kg), administered orally to rats for 26 days, caused a significant repression of paw and joint swelling associated with severe chronic adjuvant arthritis. More recently, the effectiveness of a crude ginger extract was compared with a fraction containing only gingerols and derivatives to inhibit joint swelling in the streptococcal cell wall–induced arthritis animal model of rheumatoid arthritis. Results indicated that although both extracts could prevent joint inflammation, the crude dichloromethane extract, which also contained essential oils and more polar compounds, was more effective (when normalized to gingerol content) in preventing both joint inflammation and destruction. In humans, one study showed no difference between placebo and ginger in patients with osteoarthritis of the hip or knee. In contrast, patients suffering from osteoarthritis of the knee showed a consistently greater response to treatment with ginger extract compared with the control group. In addition, relief from pain and swelling was reported in patients suffering from rheumatoid arthritis, osteoarthritis, or general muscular discomfort when using powdered ginger as a dietary supplement for 3 months to 2 years.

Besides pain relief from arthritis, results of a double-blind comparative clinical trial indicated that ginger (250-mg capsules) was as effective as the nonsteroidal anti-inflammatory drugs mefenamic acid (250 mg) and ibuprofen (400 mg) in relieving pain in women with primary dysmenorrhea. In contrast, consumption of 2 g of ginger before 30 minutes of cycling exercise (60% VO2) had no effect on quadriceps muscle pain, rating of perceived exertion, work rate, heart rate, or oxygen uptake. Researchers have hypothesized that the anti-inflammatory effects of ginger might be related to its ability to inhibit prostaglandin and leukotriene biosynthesis. Some others have showed that gingerols actively inhibit arachidonate 5-lipoxygenase, an enzyme of leukotriene biosynthesis. [8]-gingerol, but not [6]-gingerol, was shown to inhibit cyclooxygenase-2 (COX-2) expression, which is induced during inflammation to increase formation of prostaglandins. Others have also reported that ginger extract suppresses the activation of tumor necrosis factor α (TNF-α) and expression of COX-2 in human synoviocytes. Proinflammatory cytokines such as TNF-α, interleukin (IL)-1β, and IL-12, which are produced primarily by macrophages, play an important role in sepsis, ischemia/reperfusion injury, and transplant rejection. [6]-gingerol was reported to inhibit the production of proinflammatory cytokines from LPS-stimulated peritoneal macrophages, but to have no effect on the function of antigen presenting cells (APC) or the LPS-induced expression of proinflammatory chemokines.

However, this same group later reported that a ginger extract attenuated the production of IL-12, TNF-α, and IL-1β proinflammatory cytokines and RANTES (regulated upon activation, normal T cell expressed and secreted) and monocyte chemoattractant protein 1 (MCP-1) proinflammatory chemokines in LPS-stimulated murine peritoneal macrophages. In general, ginger extract inhibited macrophage activation and APC function, and indirectly suppressed T-cell activation. Other stable [6]-gingerol metabolites or analogs were reported to suppress LPSinduced NO production in murine macrophages mainly by reducing inos gene and iNOS protein production. Some of ginger’s anti-inflammatory effects appear to be associated with decreased IκBα degradation and impaired nuclear factor κB (NF-κB) nuclear translocation of p65. The majority of scientific evidence does seem to suggest that ginger and its various components have anti-inflammatory effects both in vitro and ex vivo. However, the data supporting ginger as an effective anti-inflammatory agent in humans in vivo are still contradictory and incomplete.

One of the many health claims attributed to ginger is its purported ability to decrease inflammation, swelling, and pain. [6]-gingerol, a dried ginger extract, and a dried gingerol-enriched extract were each reported to exhibit analgesic and potent anti- inflammatory effects. Earlier animal studies suggest that rat hind limbs perfused with [6]-gingerol showed increased heat production that was associated with increased oxygen consumption and lactate efflux. The thermogenesis was at least partly associated with vasoconstriction independent of adrenergic receptors or secondary catecholamine release. In contrast, larger doses of ginger components inhibited oxygen consumption, which was attributed to disruption of mitochondrial function. These results were supported in a later study in which rats that were given a single intraperitoneal injection of [6]-gingerol (2.5 or 25 mg/kg) exhibited a rapid, marked drop in body temperature and a significant decrease in metabolic rate.

Data suggest that ginger may exhibit anti-inflammatory effects through the modulation of calcium levels mediated through transient receptor potential vanilloid subtype 1 (TRPV1), which is a heatand pain-sensitive receptor that can interact with [6]-gingerol. [6]-gingerol has been reported to induce a substantial rise in intracellular calcium levels in Madin–Darby canine kidney renal tubular cells by stimulating both extracellular calcium influx and thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor)-sensitive intracellular calcium release. The gingerols are known to be TRPV1 agonists, and the [6,8,10]-gingerols and [6,8,10]-shogaols can increase the intracellular calcium concentration in TRPV1-expressing HEK293 cells through TRPV1. Shogaols appear to be more potent than the gingerols, and most of the compounds cause aversive or nociceptive responses mediated by TRPV1 when applied to the eye or following subcutaneous injection to the hind paw, respectively. In this case, most of the ginger compounds also promoted adrenal catecholamine secretion, which influences energy consumption.

The presence of oxidative stress is associated with numerous diseases and a common mechanism often put forth to explain the actions and health benefits of ginger is associated with its antioxidant properties. Ginger was reported to decrease age-related oxidative stress markers  and was suggested to guard against ethanol-induced hepatotoxicity by suppressing oxidative consequences in rats treated with ethanol. Ginger root contains a very high level (3.85 mmol/100 g) of total antioxidants, surpassed only by pomegranate and some types of berries. The phorbol ester, 12-O-tetradecanoylphorbol-13-acetate (TPA), promotes oxidative stress by activating the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system or the xanthine oxidase system or both. Ginger was reported to suppress TPA-induced oxidative stress in human promyelocytic leukemia (HL)-60 cells and Chinese hamster ovary AS52 cells. Others have shown that ginger compounds effectively inhibit superoxide production. Several reports indicate that ginger suppresses lipid peroxidation and protects the levels of reduced glutathione (GSH). Reactive nitrogen species, such as nitric oxide (NO), influence signal transduction and cause DNA damage, which contributes to disease processes.

Nitric oxide is produced by inducible nitric oxide synthase (iNOS), which is stimulated in response to various stresses. [6]-gingerol was reported to dose-dependently inhibit NO production and reduce iNOS in lipopolysaccharide (LPS)-stimulated mouse macrophages. [6]-gingerol also effectively suppressed peroxynitrite-mediated oxidative damage. Ippoushi et al. later proposed that [6]-gingerol and peroxynitrite form a symmetric dimer with [6]-gingerol covalently linked at the aromatic ring of peroxynitrite, attenuating peroxynitrite-induced oxidation and nitration reactions. [6]-shogaol, 1-dehydro-[10]-gingerdione, and [10]-gingerdione also decreased LPS-induced NO production, and [6]-shogaol and 1-dehydro-[10]-gingerdione were reported to effectively reduce iNOS expression. In the bromobenzene (BB)-induced hepatotoxicity model, orally given ginger extract (100 mg/kg body weight [BW]) normalized NO levels and total and reduced glutathione levels, and also decreased the level of lipid peroxidation. Ginger consumption has also been reported to decrease lipid peroxidation and normalize the activities of superoxide dismutase and catalase, as well as GSH and glutathione peroxidase, glutathione reductase, and glutathione-S-transferase, in rats.

Ginger supplementation before ischemia/reperfusion resulted in a higher total antioxidant capacity (i.e., normalized glutathione peroxidase and superoxide dismutase activities) and lower total oxidant (lower tissue malondialdehyde, NO, and protein carbonyl contents) status levels compared to an untreated group of Wistar albino rats. Overall, the rats fed ginger (5%) experienced less kidney damage due to oxidative stress induced by ischemia/reperfusion. Ginger extract has been reported to exert radioprotective effects in mice exposed to gamma radiation, and the effect was associated with decreased lipid peroxidation and protection of GSH levels. [6]-gingerol pretreatment also decreased oxidative stress induced by ultraviolet B (UVB) and activated caspase-3, -8, -9, and Fas expression. Evidence does seem to suggest that ginger and some of its components are effective antioxidants in vitro. However, whether the physiological activity occurs in humans.

Although ginger is one of the most widely consumed spices in the world, not a great deal is known regarding its metabolism or metabolites. Evaluating the bioactivity of ginger is necessary for completely understanding its mechanism of action and potential therapeutic effects. Although many food-derived supplements are consumed today with little knowledge of their activity or safety, more attention is beginning to be given to addressing these issues. The most well-studied bioactive component of ginger is probably [6]-gingerol. The careful isolation of several metabolites of [6]-gingerol following its oral administration (50 mg/kg) to rats was reported. A primary metabolite, (S)-[6]-gingerol-4′-O-β-glucuronide, was detected in the bile and several minor metabolites were found in β-glucuronidase-treated urine, suggesting that [6]-gingerol undergoes conjugation and oxidation of its phenolic side chain. Gingerol is rapidly cleared from rat plasma following intravenous administration (3 mg/kg), and it was reported to be metabolized enzymatically in a stereospecific reduction to gingerdiol.

A method has been developed for the simultaneous quantification of [6]-, [8]-, and [10]-gingerol and [6]-shogaol in rat plasma in pharmacokinetic studies after oral administration of ginger oleoresin. The investigators were able to identify a glucuronide of [6]-gingerol after hydrolysis of β-glucuronidase, and the intestinal glucuronidation was further confirmed by comparing plasma samples of hepatic portal vein and femoral vein. This method was also used to obtain pharmacokinetics, tissue distribution, and excretion studies of 6-gingerol after oral or intraperitoneal administration in rats. In a study in which a ginger extract (approximately 53% [6]-gingerol) was administered to rats by oral ingestion, [6]-gingerol was absorbed rapidly into the plasma, with a maximal concentration (4.23 μg/mL) being reached after 10 minutes. The [6]-gingerol was distributed to various tissues and the most concentration was found in the gastrointestinal tract. Peak concentrations of [6]-gingerol were reached in most tissues at about 30 minutes, and the concentration in tissues was higher than that in plasma.

At least one clinical trial focused on the pharmacokinetics of [6]-, [8]-, and [10]-gingerols and [6]-shogaol along with their respective conjugate metabolites. In this case, human volunteers were given ginger at doses ranging from 100 mg to 2 g and blood samples were taken at 15 minutes to 72 hours after a single oral dose. Results indicated that the free forms of [6]-, [8]-, and [10]-gingerols or [6]-shogaol were not detectable, whereas the respective glucuronide of each compound was detected, suggesting that these ginger components are readily absorbed after oral consumption and can be detected as glucuronide conjugates. Although progress in determining the active components and metabolites of ginger and understanding their pharmacokinetics has been made, more work is clearly needed.

Ginger is a member of a plant family that includes cardamom and turmeric. Its spicy aroma is mainly due to presence of ketones, especially the gingerols, which appear to be the primary component of ginger studied in much of the health-related scientific research. The rhizome, which is the horizontal stem from which the roots grow, is the main portion of ginger that is consumed. Ginger’s current name comes from the Middle English gingivere, but this spice dates back over 3000 years to the Sanskrit word srngaveram, meaning “horn root,” based on its appearance. In Greek, it was called ziggiberis, and in Latin, zinziberi. Interestingly, ginger does not grow in the wild and its actual origins are uncertain.

Indians and Chinese are believed to have produced ginger as a tonic root for over 5000 years to treat many ailments, and this plant is now cultivated throughout the humid tropics, with India being the largest producer. Ginger was used as a flavoring agent long before history was formally recorded. It was an exceedingly important article of trade and was exported from India to the Roman Empire over 2000 years ago, where it was especially valued for its medicinal properties. Ginger continued to be a highly sought after commodity in Europe even after the fall of the Roman Empire, with Arab merchants controlling the trade in ginger and other spices for centuries. In the thirteenth and fourteenth centuries, the value of a pound of ginger was equivalent to the cost of a sheep. By medieval times, it was being imported in preserved form to be used in sweets. Queen Elizabeth I of England is credited with the invention of the gingerbread man, which became a popular Christmas treat.

The use of “natural” or alternative medicines has increased markedly over the last few years. More and more older adults (i.e., baby boomers) are using complementary and alternative medicine dietary supplements and herbal remedies without advice from a physician on the assumption that these substances will have a beneficial effect. However, this might not be a safe or advisable practice. For example, at least one recent survey revealed a significant problem with herb–chemotherapeutic drug interactions in cancer patients and, notably, at least half of the herbal remedies taken by these patients lacked research data documenting their potential interactions. Regrettably, a great deal of the information regarding the effectiveness and safety of these remedies has been garnered from anecdotal or historical accounts, and much of the information offered is generally misleading and might even be detrimental.

Ginger is one of the most commonly consumed dietary condiments in the world. The oleoresin (i.e., oily resin) from the rhizomes (i.e., roots) of ginger contains many bioactive components, such as [6]-gingerol, which is the primary pungent ingredient that is believed to exert a variety of remarkable pharmacological and physiological activities. Although ginger is generally considered to be safe , the lack of a complete understanding of its mechanisms of action suggests caution in its therapeutic use. Previous reviews have emphasized the importance of careful scientific research in establishing the safety and efficacy of potential therapeutic plant remedies and in defining the risks and benefits of herbal medicine. Ginger has been used for thousands of years for the treatment of numerous ailments, such as colds, nausea, arthritis, migraines, and hypertension. The medicinal, chemical, and pharmacological properties of ginger have been extensively reviewed. Over the last few years, interest in ginger or its various components as valid preventive or therapeutic agents has increased markedly, and scientific studies focusing on verification of ginger’s pharmacological and physiological actions have likewise increased. The primary purpose of this chapter is to comprehensively examine the available scientific evidence regarding ginger’s proven effectiveness in preventing or treating a variety of pathologic conditions.

Every culture has their own traditions for using plants and herbs as medicine. Most pharmaceutical drugs actually have their origin in indigenous plants and herbs from the main continents of the world. In China, over literally thousands of years, herbalists have selected and identified the particular plants and herbs that can be taken on a daily basis for improving the physical condition, energy levels, immunity and longevity. These herbs, known as “tonic” herbs, especially distinguish Chinese herbs from anything else that may be available.

If you’ve heard the argument for eating local, how does this apply to Chinese herbs? Some people suggest that whatever condition one may be suffering, that there is in close geographic proximity, the natural remedy for the condition. In modern times, we are much more detached from our natural environment than our ancestors ever were. We typically consume foods grown in another environment. Many of today’s diseases are a result of exposure to harmful toxins and synthetic chemicals which are independent of the pure environment. Additionally, on the side of the herbs, the potency and medicinal quality of a plant in many cases may vary with the region it is grown in. Just as we may choose to enjoy chocolate from Switzerland or wine from France more than a similar product made in, for example, the Midwest of the US, many herbalists all over the world choose herbs sourced from particular regions, even if the plant can grow locally.

What about the quality of Chinese herbs? Some Chinese herbs are collected from the wild, some are grown naturally without pesticides, and some are grown with pesticides. Fortunately, most Chinese herbs are derived from seeds, roots, and tree barks that are not directly exposed to pesticides because the soil bacteria usually degrades pesticides before they can be absorbed by the roots. Many herbs are washed and processed before they go to market and any residues are removed then. Ultimately, the quantity of herbs consumed is small compared to food, so the potential for exposure is much less, relatively speaking.

How do you take Chinese herbs? Traditionally, Chinese herbs are ingested either by making a decoction (a tea made by simmering herbs in hot water for at least 45 minutes) or in powder form, sometimes compressed into pills or capsules, or added to hot water like a tea. Today, the preferred methods are to make a decoction under controlled conditions and then dry the decoction to make a concentrate, or to finely powder herbs and make them into tablets or capsules.

Do Chinese tonic herbs have side effects? We’re used to expecting often unpleasant side effects with regular prescription medication; however, the good news is that with Chinese tonic herbs rarely have any side effects at all. The intention behind a tonic herb is to balance the body as a whole, and these herbs have been chosen, through thousands of years of use and experience, for their particular kind of action on the body, so they are very safe for anyone to take.

What is the cost? The price of Chinese herbs can vary greatly. Tonic herbs, which are among the most important and unique herbs of this ancient herbal system, can range from moderate to expensive. Compared to a standard multivitamin, the retail price of a Chinese tonic herb may be relatively high for good quality products, however, Chinese herbs are very cost effective. For an investment of approximately one dollar per day, the average consumer can obtain many tangible benefits. Compare this with the amount most people are willing to spend on unhealthy food or habits (such as cigarette smoking) or on a visit to the doctor, and it is easy to see that Chinese herbs are a good investment.