Systemic administration of [6]-gingerol, a pungent constituent of ginger, induces hypothermia in rats via an inhibitory effect on metabolic rate

Ginger for Healthy Ageing: A Systematic Review on Current Evidence of Its Antioxidant, Anti-Inflammatory, and Anticancer Properties

The world's population is ageing at an accelerated pace. Ageing is a natural, physiological but highly complex and multifactorial process that all species in the Tree of Life experience over time. Physical and mental disabilities, and age-related diseases, would increase along with the increasing life expectancy. Ginger (Zingiber officinale) is a plant that belongs to the Zingiberaceae family, native to Southeast Asia. For hundreds of years, ginger has been consumed in various ways by the natives of Asian countries, both as culinary and medicinal herb for the treatment of many diseases. Mounting evidence suggests that ginger can promote healthy ageing, reduce morbidity, and prolong healthy lifespan. Ginger, a well-known natural product, has been demonstrated to possess antioxidant, anti-inflammatory, anticancer, and antimicrobial properties, as well as an outstanding antiviral activity due to a high concentration of antiviral compounds. In this review, the current evidence on the potential role of ginger and its active compounds in the prevention of ageing is discussed.

COVID-19: Is There Evidence for the Use of Herbal Medicines as Adjuvant Symptomatic Therapy?

BACKGROUND

Current recommendations for the self-management of SARS-Cov-2 disease (COVID-19) include self-isolation, rest, hydration, and the use of NSAID in case of high fever only. It is expected that many patients will add other symptomatic/adjuvant treatments, such as herbal medicines.

AIMS

To provide a benefits/risks assessment of selected herbal medicines traditionally indicated for "respiratory diseases" within the current frame of the COVID-19 pandemic as an adjuvant treatment.

METHOD

The plant selection was primarily based on species listed by the WHO and EMA, but some other herbal remedies were considered due to their widespread use in respiratory conditions. Preclinical and clinical data on their efficacy and safety were collected from authoritative sources. The target population were adults with early and mild flu symptoms without underlying conditions. These were evaluated according to a modified PrOACT-URL method with paracetamol, ibuprofen, and codeine as reference drugs. The benefits/risks balance of the treatments was classified as positive, promising, negative, and unknown.

RESULTS

A total of 39 herbal medicines were identified as very likely to appeal to the COVID-19 patient. According to our method, the benefits/risks assessment of the herbal medicines was found to be positive in 5 cases (Althaea officinalis, Commiphora molmol, Glycyrrhiza glabra, Hedera helix, and Sambucus nigra), promising in 12 cases (Allium sativum, Andrographis paniculata, Echinacea angustifolia, Echinacea purpurea, Eucalyptus globulus essential oil, Justicia pectoralis, Magnolia officinalis, Mikania glomerata, Pelargonium sidoides, Pimpinella anisum, Salix sp, Zingiber officinale), and unknown for the rest. On the same grounds, only ibuprofen resulted promising, but we could not find compelling evidence to endorse the use of paracetamol and/or codeine.

CONCLUSIONS

Our work suggests that several herbal medicines have safety margins superior to those of reference drugs and enough levels of evidence to start a clinical discussion about their potential use as adjuvants in the treatment of early/mild common flu in otherwise healthy adults within the context of COVID-19. While these herbal medicines will not cure or prevent the flu, they may both improve general patient well-being and offer them an opportunity to personalize the therapeutic approaches.

6-Gingerol attenuates LPS-induced neuroinflammation and cognitive impairment partially via suppressing astrocyte overactivation

6-Gingerol, the major component of gingerols extracted from Zingiber officinale, has been shown to exhibit anti-inflammatory and antioxidant bioactivities. Since neuroinflammation plays an important role in neurodegenerative diseases, such as Alzheimer's disease (AD), and astrocytes have been considered important in the process of neurodegeneration, it was of interest to know whether 6-gingerol reduced astrocytes activation or even attenuated cognitive impairment. Here we examined the neuroprotective effects of 6-gingerol in lipopolysaccharide (LPS)-induced disorder models both in vitro and in vivo. C6 astroglioma cells treated with LPS were found to release excessive pro-inflammatory cytokines, including TNF-α and IL-6, and also increase intercellular ROS, NO, and iNOS (i.e. NOS2). All these were blocked by 6-gingerol in a concentration-dependent manner. The spatial learning and memory of rats challenged with LPS (10 μg, i.c.v.) in the absence or presence of 6-gingerol were evaluated using the Morris water-maze (MWM) test. 6-Gingerol attenuated LPS-induced imapirement of MWM learning and memory in a dose-dependent manner. Besides, 6-gingerol inhibited LPS-induced increases in levels of GFAP and TNF-α in the rat brain. The results suggest that 6-gingerol suppresses astrocyte overactivation, through which it contributes to improvement of cognitive ability.

Neuroprotective Effect and Molecular Mechanism of [6]-Gingerol against Scopolamine-Induced Amnesia in C57BL/6 Mice

We have investigated the neuroprotective and memory enhancing effect of [6]-gingerol (GIN), a pungent ingredient of ginger, using an animal model of amnesia. To determine the neuroprotective effect of GIN on cognitive dysfunction, scopolamine (SCO, 1 mg/kg, i.p.) was injected into C57BL/6 mice, and a series of behavioral tests were conducted. SCO-induced behavior changes and memory impairments, such as decreased alteration (%) in Y-maze test, increased mean escape latency in water maze test, diminished step-through latency in passive avoidance test, and shortened freezing time in fear condition test, were significantly prevented and restored by the oral administration of GIN (10 or 25 mg/kg/day). To further verify the neuroprotective mechanism of GIN, we have focused on the brain-derived neurotrophic factor (BDNF). The administration of GIN elevated the protein expression of BDNF, which was mediated via the activation of protein kinase B/Akt- and cAMP-response element binding protein (CREB) signaling pathway. These results suggest that GIN may have preventive and/or therapeutic potentials in the management of memory deficit and cognitive impairment in mice with amnesia.

Cross-talk between 10-gingerol and its anti-cancerous potential: a recent update

Since time immortal, ginger, as an ancient herb, has been used throughout the world in foods and beverages due to its typical strong and pungent flavor. Besides its use as a spice, it also serves as an excellent source of several bioactive phenolics, including nonvolatile pungent compounds, such as gingerols, paradols, shogaols, and gingerones. Gingerols constitute key ingredients in fresh ginger, with the most abundant being 6-gingerol (6-G), 8-gingerol (8-G), and 10-gingerol (10-G). Many studies have investigated the various valuable pharmacological properties of these ingredients and experimentally verified the mechanistic aspects of their health effects; however, to date, most research on the anti-cancerous activities of gingerols have focused largely on 6-G. Thus, the present article deals with the number of recent studies that have indicated and highlighted the role of 10-G with respect to its cancer prevention attributes in particular and its anti-inflammatory, anti-oxidant, anti-microbial, and gastrointestinal tract protective potential in general. The purpose of this review is to provide an overview of all the experimentally validated health benefits of 10-G for nutraceutical applications. The various findings have warranted the further investigation of 10-G and its possible use in various cancer treatments as well as its promising role as a chemo-preventive agent.

Oral intake of encapsulated dried ginger root powder hardly affects human thermoregulatory function, but appears to facilitate fat utilization

The present study investigated the impact of a single oral ingestion of ginger on thermoregulatory function and fat oxidation in humans. Morning and afternoon oral intake of 1.0 g dried ginger root powder did not alter rectal temperature, skin blood flow, O2 consumption, CO2 production, and thermal sensation and comfort, or induce sweating at an ambient temperature of 28 °C. Ginger ingestion had no effect on threshold temperatures for skin blood flow or thermal sweating. Serum levels of free fatty acids were significantly elevated at 120 min after ginger ingestion in both the morning and afternoon. Morning ginger intake significantly reduced respiratory exchange ratios and elevated fat oxidation by 13.5 % at 120 min after ingestion. This was not the case in the afternoon. These results suggest that the effect of a single oral ginger administration on the peripheral and central thermoregulatory function is miniscule, but does facilitate fat utilization although the timing of the administration may be relevant.

Gingerols and shogaols: Important nutraceutical principles from ginger

Gingerols are the major pungent compounds present in the rhizomes of ginger (Zingiber officinale Roscoe) and are renowned for their contribution to human health and nutrition. Medicinal properties of ginger, including the alleviation of nausea, arthritis and pain, have been associated with the gingerols. Gingerol analogues are thermally labile and easily undergo dehydration reactions to form the corresponding shogaols, which impart the characteristic pungent taste to dried ginger. Both gingerols and shogaols exhibit a host of biological activities, ranging from anticancer, anti-oxidant, antimicrobial, anti-inflammatory and anti-allergic to various central nervous system activities. Shogaols are important biomarkers used for the quality control of many ginger-containing products, due to their diverse biological activities. In this review, a large body of available knowledge on the biosynthesis, chemical synthesis and pharmacological activities, as well as on the structure-activity relationships of various gingerols and shogaols, have been collated, coherently summarised and discussed. The manuscript highlights convincing evidence indicating that these phenolic compounds could serve as important lead molecules for the development of therapeutic agents to treat various life-threatening human diseases, particularly cancer. Inclusion of ginger or ginger extracts in nutraceutical formulations could provide valuable protection against diabetes, cardiac and hepatic disorders.

Effect of Zingiber officinale Supplementation on Obesity Management with Respect to the Uncoupling Protein 1 -3826A>G and ß3-adrenergic Receptor Trp64Arg Polymorphism

The present study aimed to investigate the effect of ginger (Zingiber officinale) supplementation on some obesity-associated parameters, with nutrigenetics approach. Accordingly, 80 eligible obese women (aged 18-45 years) were randomly assigned to receive either ginger (2-g ginger rhizomes powder as two 1-g tablets per day) or placebo supplements (corn starch with the same amount) for 12 weeks. Subjects were tested for changes in body weight, body mass index, waist and hip circumferences, body composition, appetite score, and dietary intake. Moreover, participants were genotyped for the -3826A>G and Trp64Arg polymorphisms of uncoupling protein 1 and ß3-adrenergic receptor genes, respectively. Over 12 weeks, ginger supplementation resulted in a slight but statistically significant decrease in all anthropometric measurements and total appetite score as compared with placebo group, which were more pronounced in subjects with the AA genotype for uncoupling protein 1 and Trp64Trp genotype for ß3-adrenergic receptor gene. However, there was no significant difference in changes of body composition and total energy and macronutrients intake between groups. In conclusion, our findings suggest that ginger consumption has potential in managing obesity, accompanying with an intervention-genotype interaction effect. However, further clinical trials need to explore ginger's efficacy as an anti-obesity agent in the form of powder, extract, or its active components.

Ginger from ancient times to the new outlook

Context:

Ginger is the rhizome of Zingiber officinale, a perennial plant, used alone or in compounds as a spice or remedy in ancient recipes of Iranian traditional medicine (ITM) as an effective tonic for the memory and digestive system, the opener of hepatic obstructions, aphrodisiac, for expelling compact wind from stomach and intestines, diluting, desiccating and emollient of phlegmatic and compact humor sticking to body organs, stomach, intestine, brain and throat. The ITM scholars believed that ginger was a vermifuge as well as a remedy for paralysis and obstructive jaundice. They also revealed that this phytomedicine cures diarrhea due to corrupted food. This study aimed to compare the medicinal properties (afaal) of ginger in ITM with those indicated in modern research.

Results:

Results of this study showed that the modern phytotherapy confirmed some of the properties of ginger. In addition, some of the properties of this phytomedicine have not been studied yet.

Conclusions:

By studding the ITM literature, herb elements or in other words ITM keywords, researchers can predict and state some unknown or less known potential pharmacologic effects of medicinal plants.

Pungent ginger components modulates human cytochrome P450 enzymes in vitro

AIM

Ginger rhizome is used worldwide as a spicy flavor agent. This study was designed to explore the potential effects of pungent ginger components, 6-, 8-, and 10-gingerol, on human cytochrome P450 (CYP450) enzymes that are responsible for the metabolism of many prescription drugs.

METHODS

The activities of human CYP2C9, CYP2C19, CYP2D6, and CYP3A4 were analyzed using Vivid P450 assay kits. The mRNA expression of CYP3A4 in human hepatocellular carcinoma cell line HepG2 was measured using quantitative real-time PCR assay.

RESULTS

All three gingerols potently inhibited CYP2C9 activity, exerted moderate inhibition on CYP2C19 and CYP3A4, and weak inhibion on CYP2D6. 8-Gingerol was the most potent in inhibition of P450 enzymes with IC50 values of 6.8, 12.5, 8.7, and 42.7 μmol/L for CYP2C9, CYP2C19, CYP3A4, and CYP2D6, respectively. By comparing the effects of gingerols on CYP3A4 with three different fluorescent substrate probes, it was demonstrated that the inhibition of gingerols on CYP3A4 had no substrate-dependence. In HepG2 cells, 8-gingerol and 10-gingerol inhibited, but 6-gingerol induced mRNA expression of CYP3A4.

CONCLUSION

6-, 8-, and 10-gingerol suppress human cytochrome P450 activity, while 8- and 10-gingerol inhibit CYP3A4 expression. The results may have an implication for the use of ginger or ginger products when combined with therapeutic drugs that are metabolized by cytochrome P450 enzymes.

Ginger consumption enhances the thermic effect of food and promotes feelings of satiety without affecting metabolic and hormonal parameters in overweight men: a pilot study

Evidence suggests that ginger consumption has anti-inflammatory, anti-hypertensive, glucose-sensitizing, and stimulatory effects on the gastrointestinal tract. This study assessed the effects of a hot ginger beverage on energy expenditure, feelings of appetite and satiety and metabolic risk factors in overweight men. Ten men, age 39.1±3.3 y and body mass index (BMI) 27.2±0.3 kg/m(2), participated in this randomized crossover study. Resting state energy expenditure was measured using indirect calorimetry and for 6h after consumption of a breakfast meal with or without 2 g ginger powder dissolved in a hot water beverage. Subjective feelings of satiety were assessed hourly using visual analog scales (VAS) and blood samples were taken fasted and for 3 h after breakfast consumption. There was no significant effect of ginger on total resting energy expenditure (P=.43) or respiratory quotient (P=.41). There was a significant effect of ginger on thermic effect of food (ginger vs control=42.7±21.4 kcal/d, P=.049) but the area under the curve was not different (P=.43). VAS ratings showed lower hunger (P=.002), lower prospective food intake (P=.004) and greater fullness (P=.064) with ginger consumption versus control. There were no effects of ginger on glucose, insulin, lipids, or inflammatory markers. The results, showing enhanced thermogenesis and reduced feelings of hunger with ginger consumption, suggest a potential role of ginger in weight management. Additional studies are necessary to confirm these findings.

Phytochemicals and their impact on adipose tissue inflammation and diabetes

Type 2 diabetes mellitus is an inflammatory disease and the mechanisms that underlie this disease, although still incompletely understood, take place in the adipose tissue of obese subjects. Concurrently, the prevalence of obesity caused by Western diet's excessive energy intake and the lack of exercise escalates, and is believed to be causative for the chronic inflammatory state in adipose tissue. Overnutrition itself as an overload of energy may induce the adipocytes to secrete chemokines activating and attracting immune cells to adipose tissue. But also inflammation-mediating food ingredients like saturated fatty acids are believed to directly initiate the inflammatory cascade. In addition, hypoxia in adipose tissue as a direct consequence of obesity, and its effect on gene expression in adipocytes and surrounding cells in fat tissue of obese subjects appears to play a central role in this inflammatory response too. In contrast, revisiting diet all over the world, there are also some natural food products and beverages which are associated with curative effects on human health. Several natural compounds known as spices such as curcumin, capsaicin, and gingerol, or secondary plant metabolites catechin, resveratrol, genistein, and quercetin have been reported to provide an improved health status to their consumers, especially with regard to diabetes, and therefore have been investigated for their anti-inflammatory effect. In this review, we will give an overview about these phytochemicals and their role to interfere with inflammatory cascades in adipose tissue and their potential for fighting against inflammatory diseases like diabetes as investigated in vivo.

An impression on current developments in the technology, chemistry, and biological activities of ginger (Zingiber officinale Roscoe)

Ginger rhizome (Zingiber officinale Roscoe) is widely cultivated as a spice for its aromatic and pungent components. The essential oil and oleoresins from ginger are valuable products responsible for the characteristic flavor and pungency. Both are used in several food products such as soft beverages and also in many types of pharmaceutical formulations. More than 100 compounds have been reported from ginger, some of which are isolated and characterized, others are tentatively identified by GC-MS and / or LC-MS. [6]-Gingerol, the major gingerol in ginger rhizomes, has been found to possess many interesting pharmacological and physiological activities, such as anti-inflammatory, analgesic, and cardiotonic effects. Ginger is considered as "generally recognized as safe" (GRAS) by Food and Drug Administration (FDA), USA. Due to all these properties, ginger has gained considerable attention in developed countries in recent years, especially for its use in the treatment of inflammatory conditions. The present review is a persuasive presentation of the current information on processing, chemistry, biological activities, and medicinal uses of ginger. Further studies are required for the validation of the beneficial uses. Formulation for novel products and new usages may emerge in the years to come, based on the revealed results of various studies.

Chemical constituents and their bioactivities of "Tongling White Ginger" (Zingiber officinale)

Gingerols and their corresponding dehydration products shogaols were considered as the active principles of ginger, the rhizome of the plant Zingiber officinale, for its antioxidant, anti-inflammatory, and antitumor activities. Ginger (Z. officinale) has been cultivated for thousands of years as a spice and for medicinal purposes in China. Tongling (Anhui province, China) has traditionally been regarded as an ideal cultivation place. "Tongling White Ginger" enjoys a reputation for being one of the top gingers in China for its thin white peel, tender flesh, rich juice, and flavor. In this study, we have isolated and identified two novel gingerdione dimers, bisgingerdiones A (1) and B (2); two new gingerol derivatives, (5R)-5-acetoxy-1,7-bis(4-hydroxy-3-methoxyphenyl)heptan-3-one (3) and methyl (Z)-neral acetal-[6]-gingerdiol (4); and 38 known compounds (5-42) from rhizomes of Zingiber officinale collected from Tongling, China. Their structures were elucidated by means of spectroscopic methods. Compounds 1-4 showed weak cytotoxic and anti-HIV-1 activities. Compounds 6, 8, and 26 showed inhibitory activities against human and mouse 11β-HSD1 (11β-hydroxysteroid dehydrogenases) with IC(50) values between 1.09 and 1.30 μM.

Ginger phytochemicals mitigate the obesogenic effects of a high-fat diet in mice: a proteomic and biomarker network analysis

SCOPE

Natural dietary anti-obesogenic phytochemicals may help combat the rising global incidence of obesity. We aimed to identify key hepatic pathways targeted by anti-obsogenic ginger phytochemicals fed to mice.

METHODS AND RESULTS

Weaning mice were fed a high-fat diet containing 6-gingerol (HFG), zerumbone (HFZ), a characterized rhizome extract of the ginger-related plant Alpinia officinarum Hance (high fat goryankang, HFGK) or no phytochemicals (high-fat control, HFC) for 6 wks and were compared with mice on a low-fat control diet (LFC). Increased adiposity in the HFC group, compared with the LFC group, was significantly (p<0.05) reduced in the HFG and HFGK groups without food intake being affected. Correlation network analysis, including a novel residuals analysis, was utilized to investigate relationships between liver proteomic data, lipid and cholesterol biomarkers and physiological indicators of adiposity. 6-Gingerol significantly increased plasma cholesterol but hepatic farnesyl diphosphate synthetase, which is involved in cholesterol biosynthesis was decreased, possibly by negative feedback. Acetyl-coenzyme A acyltransferase 1 and enoyl CoA hydratase, which participate in the β-oxidation of fatty acids were significantly (p<0.05) increased by consumption of phytochemical-supplemented diets.

CONCLUSION

Dietary ginger phytochemicals target cholesterol metabolism and fatty acid oxidation in mice, with anti-obesogenic but also hypercholesterolemic consequences.

Subacute thyroiditis following ginger (Zingiber officinale) consumption

A woman with subacute thyroiditis following ginger consumption is presented. The diagnosis was confirmed by physical examination and laboratory tests, in two distinct episodes. The patient was cured and recommended to refuse ginger consumption.

Transient receptor potential A1 increase glutamate release on brain stem neurons

Low temperature and noxious chemicals activate transient receptor potential (TRP) A1 channel in spinal nociceptive neurons. TRPA1 ligands are found as common ingredients of pungent spices and can trigger autonomic reflexes and alter blood pressure. Recent discovery of TRPA1 on visceral afferent pathway suggests such nonnociceptive responses may be closely related to TRPA1. To understand potential contributions of TRPA1 on autonomic response, we have tested TRPA1 agonist allyl isothiocyanate (AITC) effects on mechanically dispersed nucleus tractus solitarii neurons. AITC of 200 microM increased glutamate release in 58% of tested neurons and TRP channel antagonist ruthenium red (50 microM) blocked the AITC actions. tetrodotoxin and Cd did not eliminate AITC-evoked glutamate release increase. TRPA1 expressed in capsaicin-sensitive and insensitive neurons.