Effect of gingerol on colonic motility via inhibition of calcium channel currents in rats

Therapeutic health effects of ginger (Zingiber officinale): updated narrative review exploring the mechanisms of action

Ginger (Zingiber officinale) has been investigated for its potentially therapeutic effect on a range of chronic conditions and symptoms in humans. However, a simplified and easily understandable examination of the mechanisms behind these effects is lacking and, in turn, hinders interpretation and translation to practice, and contributes to overall clinical heterogeneity confounding the results. Therefore, drawing on data from nonhuman trials, the objective for this narrative review was to comprehensively describe the current knowledge on the proposed mechanisms of action of ginger on conferring therapeutic health effects in humans. Mechanistic studies support the findings from human clinical trials that ginger may assist in improving symptoms and biomarkers of pain, metabolic chronic disease, and gastrointestinal conditions. Bioactive ginger compounds reduce inflammation, which contributes to pain; promote vasodilation, which lowers blood pressure; obstruct cholesterol production, which regulates blood lipid profile; translocate glucose transporter type 4 molecules to plasma membranes to assist in glycemic control; stimulate fatty acid breakdown to aid weight management; and inhibit serotonin, muscarinic, and histaminergic receptor activation to reduce nausea and vomiting. Additional human trials are required to confirm the antimicrobial, neuroprotective, antineoplastic, and liver- and kidney-protecting effects of ginger. Interpretation of the mechanisms of action will help clinicians and researchers better understand how and for whom ginger may render therapeutic effects and highlight priority areas for future research.

Preparation, pungency and bioactivity of gingerols from ginger (Zingiber officinale Roscoe): a review

Ginger has been widely used for different purposes, such as condiment, functional food, drugs, and cosmetics. Gingerols, the main pungent component in ginger, possess a variety of bioactivities. To fully understand the significance of gingerols in the food and pharmaceutical industry, this paper first recaps the composition and physiochemical properties of gingerols, and the major extraction and synthesis methods. Furthermore, the pungency and bioactivity of gingerols are reviewed. In addition, the food application of gingerols and future perspectives are discussed. Gingerols, characterized by a 3-methoxy-4-hydroxyphenyl moiety, are divided into gingerols, shogaols, paradols, zingerone, gingerdiones and gingerdiols. At present, gingerols are extracted by conventional, innovative, and integrated extraction methods, and synthesized by chemical, biological and in vitro cell synthesis methods. Gingerols can activate transient receptor potential vanilloid type 1 (TRPV1) and induce signal transduction, thereby exhibiting its pungent properties and bioactivity. By targeted mediation of various cell signaling pathways, gingerols display potential anticancer, antibacterial, blood glucose regulatory, hepato- and renal-protective, gastrointestinal regulatory, nerve regulatory, and cardiovascular protective effects. This review contributes to the application of gingerols as functional ingredients in the food and pharmaceutical industry.

Natural Polyphenols as SERCA Activators: Role in the Endoplasmic Reticulum Stress-Related Diseases

Sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA) is a key protein responsible for transporting Ca²⁺ ions from the cytosol into the lumen of the sarco/endoplasmic reticulum (SR/ER), thus maintaining Ca²⁺ homeostasis within cells. Accumulating evidence suggests that impaired SERCA function is associated with disruption of intracellular Ca²⁺ homeostasis and induction of ER stress, leading to different chronic pathological conditions. Therefore, appropriate strategies to control Ca²⁺ homeostasis via modulation of either SERCA pump activity/expression or relevant signaling pathways may represent a useful approach to combat pathological states associated with ER stress. Natural dietary polyphenolic compounds, such as resveratrol, gingerol, ellagic acid, luteolin, or green tea polyphenols, with a number of health-promoting properties, have been described either to increase SERCA activity/expression directly or to affect Ca²⁺ signaling pathways. In this review, potential Ca²⁺-mediated effects of the most studied polyphenols on SERCA pumps or related Ca²⁺ signaling pathways are summarized, and relevant mechanisms of their action on Ca²⁺ regulation with respect to various ER stress-related states are depicted. All data were collected using scientific search tools (i.e., Science Direct, PubMed, Scopus, and Google Scholar).

Effects of standardized [6]-gingerol extracts and [6]-gingerol on isolated ileum and lower esophageal sphincter contractions in mice

Standardized [6]-gingerol extracts were prepared by microwave-assisted extraction using 20% v/v glycerin in ethanol and 20% v/v eutectic mixture of sucrose and citric acid in ethanol as alternative green solvents. The extracts obtained from 20% v/v glycerin in ethanol (GEE) and 20% v/v eutectic mixture of sucrose and citric acid in ethanol (EMSCEE) were standardized by HPLC to contain 17.0 mg/g of [6]-gingerol. The effects of the extracts on mouse ileal contractions via M3 and 5-HT3 receptors as well as lower esophageal sphincter (LES) contraction were determined in vitro relative to the marker compound, [6]-gingerol. [6]-Gingerol, GEE and EMSCEE demonstrated significant and concentration-dependent inhibitory effects on ileal contraction in mice via M3 and 5-HT3 receptors in a noncompetitive manner. In addition, [6]-gingerol and EMSCEE tend to increase the LES tone. These results indicated the potential of GEE and EMSCEE to attenuate nausea and vomiting and might be used as nutraceuticals.

Short-chain fatty acids promote jejunal barrier function and caecal muscle contractibility in laying hens ex vivo

1. Short-chain fatty acids (SCFA) exert beneficial actions in the gut; nevertheless, information about the effect of SCFA on physiological responses in the small intestine of chickens is rare.2. The aim of this study was to assess the effect of 1) different molar acetate:butyrate ratios (Ac:But; Experiment 1; 78.5% acetate and 7.3% butyrate versus 71.4% acetate and 14.0% butyrate) and 2) SCFA concentrations (Experiment 2; final concentration in chambers: 70.5 versus 141 µmol SCFA/ml buffer) on the jejunal and caecal contractibility and jejunal barrier function in laying hens. The change in muscle contractibility due to the SCFA was measured in mid-jejunal and caecal segments (n = 4 each per hen) from four laying hens using the organ bath system after precontraction with acetylcholine for 15 min. Changes in short-circuit current (I_SC) and transepithelial tissue conductivity (G_T) as indicators for net ion flux and barrier function, respectively, were measured in mid-jejunal tissue (n = 3/hen and treatment), mounted into Ussing chambers.3. In Experiment 1, the addition of SCFA, irrespective of the Ac:But ratio, decreased jejunal muscle tension (P < 0.05), jejunal G_T as well as caused a less negative I_SC (P < 0.05). In Experiment 2, the increasing SCFA concentrations increased the caecal muscle contraction and jejunal I_SC by 75.6% while decreasing the G_T by up to 19.6% (P < 0.05).4. In conclusion, results demonstrate that increasing butyrate proportions and SCFA concentrations stimulate caecal muscle contraction, thereby increasing caecal mixing and emptying in vivo. Jejunal I_SC and G_T support a strong SCFA sensing capacity in the jejunum, as both, more butyrate and higher SCFA, increased mucosal ion uptake and barrier function.

Cinnamon bark oil and coconut oil emulsions modified small intestinal motility and barrier function in laying hens in an ex vivo experiment

1. Plant extracts and oils are supplemented in diets for chickens due to their antimicrobial capacities; however, little information exists whether they influence intestinal motility and barrier function.2. The present study aimed to determine the effect of increasing levels of cinnamon bark oil (CBO; 0%, 0.038%, 0.076% and 0.151%) and coconut oil emulsions prepared with soy and sunflower lecithin on the contractile function of enteric wall muscles in the jejunum and ileum and jejunal barrier function in laying hens.3. For testing muscle contraction, mid-jejunal and ileal segments (n = 4 each per hen) from four laying hens were placed in a longitudinal orientation into isolated organ baths filled with Krebs buffer and fastened to force transducers. Muscle segments were induced to contract with acetylcholine and the effects of the oil emulsions on contraction were measured.4. For barrier function, distal jejunal pieces were stripped of serosa before mounting into Ussing chambers and recording changes in short-circuit current (I_SC) and transepithelial tissue conductivity (G_T) before and after addition of the respective emulsion.5. The CBO decreased the muscle tone, representing a relaxation of on average 36.2% and 42.6% for the jejunum and ileum, respectively, compared to before the addition (P < 0.001). Moreover, CBO linearly decreased the I_SC and G_T of the jejunal mucosa, indicating a greater absorption of anions and increased barrier function (P < 0.001). Only the coconut oil-sunflower lecithin emulsion relaxed the muscles, whereas both coconut oil-lecithin emulsions increased the I_SC but reduced the G_T of the jejunal mucosa, which suggested an increased cation absorption and decreased paracellular permeability, respectively (P < 0.05).6. In conclusion, CBO and coconut oil-lecithin emulsions showed the potential to increase jejunal barrier function, whereas CBO may be more efficacious to slow down digesta passage in the small intestine.

Natural Negative Allosteric Modulators of 5-HT₃ Receptors

Chemotherapy-induced nausea and vomiting (CINV) remain the most common and devastating side-effects associated with cancer chemotherapy. In recent decades, several lines of research emphasize the importance of 5-hydroxytryptamine3 (5-HT3; serotonin) receptors in the pathogenesis and treatment of CINV. 5-HT₃ receptors are members of ligand-gated ion channels that mediate the rapid and transient membrane-depolarizing effect of 5-HT in the central and peripheral nervous system. These receptors play important roles in nausea and vomiting, as well as regulation of peristalsis and pain transmission. The development of antagonists for 5-HT₃ receptor dramatically improved the treatment of CINV in cancer patients. In fact, the most common use of 5-HT₃ receptor antagonists to date is the treatment of nausea and vomiting. In recent years, there has been an increasing tendency to use natural plant products as important therapeutic entities in the treatment of various diseases. In this article, we examined the results of earlier studies on the actions of natural compounds on the functional properties of 5-HT₃ receptors. It is likely that these natural modulators of 5-HT₃ receptors can be employed as lead structures for the synthesis of therapeutic agents for treating CINV in future clinical studies.

Ginger Extract and [6]-Gingerol Inhibit Contraction of Rat Entire Small Intestine

This study aims to investigate the effect of oral administration and the direct action of ginger extract or [6]-gingerol on small intestinal contractility. The direct effect of 10 minutes preincubation of ginger ethanolic extract (10, 100 and 300 μg/mL) or [6]-gingerol (1, 30, and 100 μM) on 0.01 to 30 μM ACh-induced contractions of all parts of the small intestine isolated from normal rats was investigated using the organ bath technique. For in vivo study, the rats were orally administered with extract (10, 20, and 100 mg/kg/d) or [6]-gingerol (2 mg/kg/d) for 7 days, followed by determining the contractile responses to ACh of rat isolated duodenum, jejunum, and ileum and their histology were assessed. Direct application of the extract or [6]-gingerol attenuated ACh-induced contractions in each small intestinal segment, E_max was reduced by 40% to 80%, while EC₅₀ increased 3- to 8-fold from control. Similarly, in the in vivo study ACh-induced contractions were reduced in all parts of the small intestine isolated from rats orally treated with ginger extract (20 and 100 mg/kg/d) or [6]-gingerol (2 mg/kg/d). E_max decreased 15% to 30%, while EC₅₀ increased 1- to 3-fold compared to control. No discernable changes in the histology of intestinal segments were detectable. Thus, the results support the clinical application of ginger for disorders of gastrointestinal motility.

Impact of Food Components on in vitro Calcitonin Gene-Related Peptide Secretion-A Potential Mechanism for Dietary Influence on Migraine

Calcitonin gene-related peptide (CGRP) is a pivotal messenger in the inflammatory process in migraine. Limited evidence indicates that diet impacts circulating levels of CGRP, suggesting that certain elements in the diet may influence migraine outcomes. Interruption of calcium signaling, a mechanism which can trigger CGRP release, has been suggested as one potential route by which exogenous food substances may impact CGRP secretion. The objective of this study was to investigate the effects of foods and a dietary supplement on two migraine-related mechanisms in vitro: CGRP secretion from neuroendocrine CA77 cells, and calcium uptake by differentiated PC12 cells. Ginger and grape pomace extracts were selected for their anecdotal connections to reducing or promoting migraine. S-petasin was selected as a suspected active constituent of butterbur extract, the migraine prophylactic dietary supplement. Results showed a statistically significant decrease in stimulated CGRP secretion from CA77 cells following treatment with ginger (0.2 mg dry ginger equivalent/mL) and two doses of grape pomace (0.25 and 1.0 mg dry pomace equivalent/mL) extracts. Relative to vehicle control, CGRP secretion decreased by 22%, 43%, and 87%, respectively. S-petasin at 1.0 μM also decreased CGRP secretion by 24%. Meanwhile, S-petasin and ginger extract showed inhibition of calcium influx, whereas grape pomace had no effect on calcium. These results suggest that grape pomace and ginger extracts, and S-petasin may have anti-inflammatory propensity by preventing CGRP release in migraine, although potentially by different mechanisms, which future studies may elucidate further.