Effects of a bitter substance, denatonium benzoate, on pancreatic hormone secretion.

There is increasing evidence linking bitter taste receptor (BTR) signaling to gut hormone secretion and glucose homeostasis. However, its effect on islet hormone secretion has been poorly characterized. This study investigated the effect of the bitter substance, denatonium benzoate (DB), on hormone secretion from mouse pancreatic islets and INS-1 832/13 cells. DB (0.5-1 mM) augmented insulin secretion at both 2.8 mM and 16.7 mM glucose. This effect was no longer present at 5 mM DB likely due to the greater levels of cellular apoptosis. DB-stimulated insulin secretion involved closure of the KATP channel, activation of T2R signaling in beta-cells, and intraislet glucagon-like peptide-1 (GLP-1) release. DB also enhanced glucagon and somatostatin secretion, but the underlying mechanism was less clear. Together, this study demonstrates that the bitter substance, DB, is a strong potentiator of islet hormone secretion independent of glucose. This observation highlights the potential for widespread off-target effects associated with the clinical use of bitter-tasting substances.NEW & NOTEWORTHY We show that the bitter substance, denatonium benzoate (DB), stimulates insulin, glucagon, somatostatin, and GLP-1 secretion from pancreatic islets, independent of glucose, and that DB augments insulin release via the KATP channel, bitter taste receptor signaling, and intraislet GLP-1 secretion. Exposure to a high dose of DB (5 mM) induces cellular apoptosis in pancreatic islets. Therefore, clinical use of bitter substances to improve glucose homeostasis may have unintended negative impacts beyond the gut.

Gengricin®: A Nutraceutical Formulation for Appetite Control and Therapeutic Weight Management in Adults Who Are Overweight/Obese.

In the field of nutritional science and metabolic disorders, there is a growing interest in natural bitter compounds capable of interacting with bitter taste receptors (TAS2Rs) useful for obesity management and satiety control. This study aimed to evaluate the effect of a nutraceutical formulation containing a combination of molecules appropriately designed to simultaneously target and stimulate these receptors. Specifically, the effect on CCK release exerted by a multi-component nutraceutical formulation (Cinchona bark, Chicory, and Gentian roots in a 1:1:1 ratio, named Gengricin®) was investigated in a CaCo-2 cell line, in comparison with Cinchona alone. In addition, these nutraceutical formulations were tested through a 3-month randomized controlled trial (RCT) conducted in subjects who were overweight-obese following a hypocaloric diet. Interestingly, the Gengricin® group exhibited a significant greater weight loss and improvement in body composition than the Placebo and Cinchona groups, indicating its effectiveness in promoting weight regulation. Additionally, the Gengricin® group reported higher satiety levels and a significant increase in serum CCK levels, suggesting a physiological basis for the observed effects on appetite control. Overall, these findings highlight the potential of natural nutraceutical strategies based on the combination of bitter compounds in modulating gut hormone release for effective appetite control and weight management.

The Effects of a Cinchona Supplementation on Satiety, Weight Loss and Body Composition in a Population of Overweight/Obese Adults: A Controlled Randomized Study.

Obesity is a risk factor for several diseases present worldwide. Currently, dietary changes and physical activity are considered the most effective treatment to reduce obesity and its associated comorbidities. To promote weight loss, hypocaloric diets can be supported by nutraceuticals. The aim of this study was to evaluate the effects of a hypocaloric diet associated with Cinchona succirubra supplementation on satiety, body weight and body composition in obese subjects. Fifty-nine overweight/obese adults, were recruited, randomized into two groups and treated for 2 months. The first group (32 adults) was treated with a hypocaloric diet plus cinchona supplementation (the T-group); the second one (27 adults) was treated with a hypocaloric diet plus a placebo supplementation (the P-group). Anthropometric-measurements as well as bioimpedance analysis, a Zung test and biochemical parameters were evaluated at baseline and after 60 days. T-group adults showed significant improvement in nutritional status and body composition compared to those at the baseline and in the P-group. Moreover, T-group adults did not show a reduction in Cholecystokinin serum levels compared to those of P-group adults. In conclusion, our data demonstrate that a hypocaloric diet associated with cinchona supplementation is effective in inducing more significant weight loss and the re-establishment of metabolic parameters than those obtained with a hypocaloric diet.

Morus alba L. Leaves (WML) Modulate Sweet (TAS1R) and Bitter (TAS2R) Taste in the Studies on Human Receptors - A New Perspective on the Utilization of White Mulberry Leaves in Food Production?

From the nutritional perspective, the main direction of the utilization of white mulberry (Morus alba L.) parts so far has been to produce dietary supplements or functional foods for individuals with diabetes or over-weight. Its leaves are widely known as a valuable source of bioactive compounds responsible for its antioxidant and antidiabetic effects, both in animals and humans. The authors found that processed leaves can also be investigated as potential bitter and/or sweet taste modulators-an important property of new functional foods. The study aimed to validate the inhibitory effect of Morus alba L. on the TAS2R3 and TAS2R13 bitter taste and TSA1R2/TSA1R3 receptors and determine the changes that the conditioning process caused in such receptors. The effect on the receptors was evaluated in specially transfected HEK293T cells, and the inhibition ratio was measured using the calcium release test. Moreover, the stability of phenolics in the simulated intestinal in vitro digestion process was determined. Results showed that the Morus alba leaf extracts were rich in gallic, chlorogenic and caffeic acids together with rutin and quercetin 3-(6-malonyl)-glucoside, while the conditioning process positively affected their amount. Most identified phenolics were reduced during in vitro digestion. In the taste receptors test, it was found that the phytochemicals from conditioned Morus alba leaf extract enhanced sweet taste, together with a reduction of bitter taste receptor activity in some cases. To conclude, the study has found that Morus alba, especially when conditioned for 4 h, seems to be a valuable modulator of taste, which should be considered in future research as a crucial reason for its new utilization.

Efficacy and safety of probiotic-supplemented bismuth quadruple therapy for the treatment of Helicobacter pylori infection: a systematic review and meta-analysis.

OBJECTIVE: We performed a meta-analysis to determine whether the addition of probiotics to the bismuth quadruple therapy (BQT) for Helicobacter pylori would improve the incidence of eradication and reduce that of side effects. METHODS: Randomized controlled trials matching the inclusion criteria were collected from PubMed, Embase, Web of Science, and The Cochrane Central Register of Controlled Trials. A Mantel-Haenszel random-effects model was used to calculate pooled risk ratios (RRs) and 95% confidence intervals (CIs) for the incidences of eradication rate, side effects as a whole, diarrhea, and other side effects. RESULTS: Ten studies were selected for inclusion in the meta-analysis. The pooled RRs for the eradication rates in intention-to-treat and per-protocol analyses of the probiotic group vs. the control group were 1.07 (95% CI: 1.02-1.11) and 1.04 (95% CI: 1.00-1.07), respectively. Probiotic supplementation reduced the incidences of side effects (RR 0.58, 95% CI: 0.37-0.91), diarrhea (RR 0.41, 95% CI: 0.25-0.67), and bitter taste (RR 0.63, 95% CI: 0.40-0.99). CONCLUSIONS: The results of this meta-analysis support the use of probiotics in combination with BQT in the clinical management of patients with H. pylori infection.

Citrus Flavonoids Supplementation as an Alternative to Replace Zinc Oxide in Weanling Pigs' Diets Minimizing the Use of Antibiotics.

Since citrus flavonoids have antioxidant and anti-inflammatory properties, it was hypothesized that these compounds would become a suitable alternative to the use of therapeutic doses of zinc oxide at weaning. A total of 252 weaned pigs ([LargeWhite × Landrace] × Pietrain) were distributed according to BW (5.7 kg ± 0.76) into 18 pens (6 pens per diet, 14 pigs/pen). Three experimental diets for the prestarter (0-14 d postweaning) and starter (15-35 d postweaning) period were prepared: (i) a nonmedicated (CON) diet, (ii) a CON diet supplemented with zinc oxide at 2500 mg/kg, amoxicillin at 0.3 mg/kg and apramycin at 0.1 mg/kg (ZnO), and (iii) CON diet with the addition of a commercial citrus flavonoid extract at 0.3 mg/kg and amoxicillin at 0.3 mg/kg (FLAV). Pig BW, ADG, ADFI, and FCR were assessed on d7, d14, and d35. Samples of intestinal tissue, cecal content, and serum were collected on day seven (18 piglets). FLAV treatment achieved greater BW and ADG during the starter and for the entire experimental period compared with the CON diet (p < 0.05), whereas ZnO pigs evidenced intermediate results. Jejunum tissue analysis showed that pigs fed the FLAV diet overexpressed genes related to barrier function, digestive enzymes, and nutrient transport compared to those pigs fed the CON diet (p < 0.05). An increase in the abundance of bacterial genera such as Succinivibrio, Turicibacter, and Mitsuokella (p < 0.05) was observed in the FLAV compared with the CON and ZnO piglets. ZnO and FLAV increased the expression of TAS2R39, while ZnO pigs also expressed greater TAS2R16 than CON (p < 0.05) in the intestine. FLAV treatment improved the gut function, possibly explaining a higher performance at the end of the nursery period. Consequently, citrus flavonoids supplementation, together with amoxicillin, is a promising alternative to the use of zinc oxide plus amoxicillin and apramycin in weanling pigs, minimizing the use of antibiotics.

Characteristics of Leaf Spot Disease Caused by Didymella Species and the Influence of Infection on Tea Quality.

Leaf spots are the most damaging and common foliar diseases of tea and are caused by several species of fungi. During 2018 to 2020, leaf spot diseases showing different symptoms (large and small spots) were observed in commercial tea plantations in Guizhou and Sichuan provinces of China. The pathogen causing the two different sized leaf spots was identified as the same species (Didymella segeticola) based on morphological characteristics, pathogenicity, and multilocus phylogenetic analysis using the combined ITS, TUB, LSU, and RPB2 gene regions. Microbial diversity analysis of lesion tissues from small spots on naturally infected tea leaves further confirmed Didymella to be present as the main pathogen. Results of sensory evaluation and quality-related metabolite analysis of tea shoots infected with the small leaf spot symptom indicated that D. segeticola negatively affected the quality and flavor of tea by changing the composition and content of caffeine, catechins, and amino acids. In addition, the significantly reduced amino acid derivatives in tea are confirmed to be positively associated with the enhanced bitter taste. The results improve our understanding of the pathogenicity of Didymella species and the influence of Didymella on the host plant, Camellia sinensis.

[Combined anti-bitterness strategy for extremely bitter characteristics of Andrographis Herba decoction and mechanism].

Three kinds of excipients were selected to investigate the anti-bitterness effect on the extremely bitter characteristics of Andrographis Herba decoction, and the optimal combined anti-bitterness formula was obtained. The preparation principle of different excipients was clarified by virtual screening and experimental verification to explore the advantages of the three kinds of excipients in the combined anti-bitterness effect. Sensory evaluation showed that mPEG_(2000)-PLLA_(2000), γ-cyclodextrin(γ-CD), and aspartame all had good anti-bitterness effect, which reduced the bitterness intensity of Andrographis Herba decoction by 0.5, 6, and 3 points, respectively. The anti-bitterness effect was superior when 0.15% mPEG_(2000)-PLLA_(2000), 1.60% γ-CD, and 0.04% aspartame were combined, and the taste score of the Andrographis Herba decoction decreased from 8 points(severe bitterness) to 1 point(almost no bitterness). Quantum chemistry calculations showed that mPEG_(2000)-PLLA_(2000) reduced the electrostatic potential of bitter groups, which spontaneously combined with it and formed a physical barrier, hindering the binding of bitter components to receptors. The interaction between γ-CD and bitter components was studied. It was found that the surface area and free energy of γ-CD decreased and the dipole moment increased, indicating that γ-CD included bitter components and self-assembled to form supramolecules. Molecular docking showed that hydroxy at position 14 and carbonyl at position 16 of andrographolide, and hydroxy at position 3 and 4, carbonyl at position 14, and five-membered lactone ring of dehydrated andrographolide were possibly the main bitter groups. The binding free energies of aspartame to bitter receptors TAS2 R10, TAS2 R14, and TAS2 R46 were-3.21,-1.55, and-2.52 kcal·mol~(-1), respectively, indicating that aspartame competed to inhibit the binding of bitter groups to bitter receptors. The results of content determination showed that the free amounts of andrographolide and dehydrated andrographolide in Andrographis Herba decoction were 0.23% and 0.28% respectively, while after adding flavor masking excipients, the dissociation amount of andrographolide and dehydrated andrographolide in the decoction decreased to 0.13% and 0.20%, respectively. The above results show that mPEG_(2000)-PLLA_(2000) involves some bitter components into it through micellar self-assembly to reconcile the entrance bitterness, and γ-CD includes the remaining bitter components in the real solution to control the main bitter taste. Aspartame further competes to inhibit the combination of bitter components and bitter receptors, and improves the taste to be sweet. Multi-excipients combined with anti-bitterness strategy significantly reduces the free concentration of bitter substances in Andrographis Herba decoction, and optimizes the taste of the decoction.

[Comparison of odor and quality of Galli Gigerii Endothelium Corneum derived from domestic chickens and broilers].

Galli Gigerii Endothelium Corneum(GGEC) is commonly used for the clinical treatment of indigestion, vomiting, diarrhea, and infantile malnutrition with accumulation. In recent decades, omnivorous domestic chickens, the original source of GGEC, has been replaced by broilers, which may lead to significant changes in the quality of the yielding GGEC. Through subjective and objective sensory evaluation, biological evaluation, and chemical analysis, this study compared the odor and quality between GGEC derived from domestic chickens and that from broilers. The odor intensity between them was compared by odor profile analysis and it was found that the fishy odor of GGEC derived from domestic chickens was significantly weaker than that of GGEC from broilers. Headspace-solid phase microextraction-gas chromatography-triple quadrupole tandem mass spectrometry(HS-SPME/GC-QQQ-MS/MS) suggested that the overall odor-causing chemicals were consistent with the fishy odor-causing chemicals. According to the odor activity va-lue and the orthogonal partial least squares discriminant analysis(OPLS-DA) result, dimethyl trisulfide, 2-methoxy-3-isobutylpyrazine, and 2-methylisoborneol were responsible for the fishy odor(OAV≥1) and the content of fishy odor-causing chemicals in GGEC derived from broilers was 1.12-2.13 folds that in GGEC from domestic chickens. The average pepsin potency in GGEC derived from broilers was 15.679 U·mg~(-1), and the corresponding figure for the medicinal from domestic chickens was 26.529 U·mg~(-1). The results of pre-column derivatization reverse-phase high-performance liquid chromatography(RP-HPLC) assay showed that the content of total amino acids and digestion-promoting amino acids in domestic chickens-derived GGEC was 1.12 times and 1.15 times that in GGEC from broilers, and the bitter amino acid content was 1.21 times folds that of the latter. In conclusion, GGEC derived from domestic chickens had weaker fishy odor, stronger enzyme activity, higher content of digestion-promoting amino acids, and stronger bitter taste than GGEC from broilers. This study lays a scientific basis for studying the quality variation of GGEC and provides a method for identifying high-quality GGEC. Therefore, it is of great significance for the development and cultivation of GGEC as both food and medicine and breeding of corresponding varieties.

[Key techniques for granulation and flavor masking of innovative Chinese medicinal preparations for children: a review].

There are many kinds of pharmaceutical preparations for children in China, which are generally divided into oral solid preparations and oral liquid preparations. Solid preparations, such as microtablets, pellets, dispersible tablets, and fine granules, have become the development trend of pediatric drugs. Liquid preparations mainly include syrup, suspension, oral solution, and drops. The poor taste and the treatment of drugs in children of different ages are the key factors affecting the efficacy, safety, and compliance of pediatric drugs. To reduce the risk caused by the fluctuation of blood concentration and improve the oral compliance of pediatric drugs, it is urgent to develop new techniques for granulation and flavor maskingto improve the poor taste of solid preparations. For liquid pre-parations with poor taste, the flavor correction technique should be used. This paper summarized the new pharmaceutical techniques for granulation and flavor masking, and it was found that sustained/controlled-releasegranules, fine granules, and chewing solid mini-tablets became the mainstream of oral solid preparations for children. Generally, multiparticle preparation, coating, microencapsulation, and other granulating techniques were involved in these preparations. Granulation and flavor masking are closely related and synergetic. Flavor masking techniques mask the bitter taste of Chinese medicine from four aspects, including confusing the brain taste, changing the compounds, reducing the exposure of bitter molecules to bitter receptors in the mouth, and numbing the taste cells to increase the threshold of bitter perception. At present, the main drugs for children on the market mainly inhibit the oral release of bitter drugs.

Oral berberine ameliorates high-fat diet-induced obesity by activating TAS2Rs in tuft and endocrine cells in the gut.

BACKGROUND AND AIMS: Although oral berberine, a natural compound extracted from the Chinese herbal medicine curcumin, has low bioavailability, it is still effective in suppressing obesity; however, the underlying mechanism is unclear. Berberine can bind to bitter-taste receptors (TAS2Rs) in intestinal endocrine secretin tumor (STC-1) cells to promote glucagon-like peptide-1 (GLP-1) secretion. Notably, TAS2Rs also exist in the tuft cells of the gut. Therefore, this study aimed to explore whether the beneficial effect of oral berberine on obesity is dependent on bitter-taste signaling in the tuft cells of the gut. METHODS AND RESULTS: Standard chow diet (SCD) or high-fat diet (HFD) was administered to C57BL/6 mice, with or without berberine (100 mg/kg, 200 mg/kg, p. o.). The PLCß2 inhibitor U73122 was used to verify whether the anti-obesity effect of berberine was dependent on the bitter-taste signaling pathway. In this study, we observed that the oral administration of berberine alleviated HFD-induced obesity in mice that U73122 partially inhibited. Both in vivo and ex vivo, berberine upregulated the release of GLP-1, promoted the proliferation of tuft cells and secretion of IL-25 in obesity via the TAS2R signaling pathway. CONCLUSIONS: Oral berberine ameliorated HFD-induced obesity through the TAS2R-IL-25 signaling pathway in tuft cells in the gut. SIGNIFICANCE: We identified and functionally characterized the TAS2Rs and Gα-gustducin/Gß1γ13 signaling pathway utilized by tuft cells in response to oral berberine in obese mice and proposed a new mechanism underlying the anti-obesity effect of berberine.

Detection of Bitterness in Vitamins Is Mediated by the Activation of Bitter Taste Receptors.

Vitamins are known to generate bitterness, which may contribute to an off-taste or aftertaste for some nutritional supplements. This negative sensation can lead to a reduction in their consumption. Little is known about the bitter taste threshold and taste sensing system for the bitter taste detection of vitamins. To better understand the mechanisms involved in bitterness perception, we combined taste receptor functional assays and sensory analysis. In humans, bitter taste detection is mediated by 25 G-protein-coupled receptors belonging to the TAS2R family. First, we studied the bitterness of thirteen vitamins using a cellular-based functional taste receptor assay. We found four vitamins that can stimulate one or more TAS2Rs. For each positive molecule-receptor combination, we tested seven increasing concentrations to determine the half-maximal effective concentration (EC50) and the cellular bitter taste threshold. Second, we measured the bitter taste detection threshold for four vitamins that exhibit a strong bitter taste using a combination of ascending series and sensory difference tests. A combination of sensory and biological data can provide useful results that explain the perception of vitamin bitterness and its real contribution to the off-taste of nutritional supplements.

Activation Spectra of Human Bitter Taste Receptors Stimulated with Cyclolinopeptides Corresponding to Fresh and Aged Linseed Oil.

Linseed oil is rich in unsaturated fatty acids, and its increased consumption could aid in health-promoting nutrition. However, rapid oxidation of linseed oil and concomitant development of bitterness impair consumers' acceptance. Previous research revealed that cyclolinopeptides, a group of cyclic peptides inherent to linseed oil, dominantly contribute to the observed bitterness. In the present study, fresh and stored linseed oil and flaxseed were analyzed for the presence of cyclolinopeptides using preparative high-performance liquid chromatography combined with mass spectrometry- and nuclear magnetic resonance-based identification and quantification. The purified compounds were tested for the activation of all 25 human bitter taste receptors of which only two responded exclusively to methionine-oxidized cyclolinopeptides. Of those, the methionine sulfoxide-containing cyclolinopeptide-4 elicited responses at relevant concentrations. We conclude that this compound is the main determinant of linseed oil's bitterness and propose strategies to reduce the development of bitterness.

The significance of saponins in shaping the quality of food products from red beet.

BACKGROUND: Food products made from red beet have aroused growing interest among consumers owing to their health qualities. The quality of food products is determined to a large extent by the ingredients they are produced from. The health properties and sensory qualities of a given product are the most important features for consumers when choosing a particular product. The triterpene saponins in red beets constitute a group of compounds which influence the sensory quality of food products from this raw material. However, neither the biological activity of nor the bitter taste caused by red beet saponins has been comprehensively described in the literature. The aim of this research was to determine the influence of saponins on the sensory quality of products which incorporate red beets. METHODS: The analysed food products were juices made from three cultivars of red beet roots. Sensory evaluation of the obtained juices and analytical sensory study of the bitter taste of saponins was carried out. The bitter taste recognition thresholds of saponins isolated from the cultivars under study were used to analyse the taste qualities of the finished products. RESULTS: The taste qualities of the analysed food products depended on the content of saponins in the final product. As compounds contributing to the bitter taste of red beets, saponins influenced the sensory qualities of the finished food products. In the case of saponins isolated from the analysed beet cultivars, it was found that the values of the defined thresholds of bitter taste recognition were higher than the saponin content in the juices obtained from these cultivars. As a result, the bitter features of juice are not detected due to the low content of saponins in them. This analysis was confirmed by the sensory evaluation of the juices, during which a team of selected evaluators indicated that sweet was the dominant flavour of the juices from Forono, Modana and Tytus cultivars, and that there was no clear sensation of its bitter features. CONCLUSIONS: Based on the determined thresholds of bitter taste recognition in saponins isolated from different beet cultivars (minimum concentration causing the sensation of bitter taste in red beet) and the comparison with the total saponin content in the final product, one can conclude whether or not a given product demonstrates bitter features. The application potential of the red beet cultivars under study was indicated as regards their suitability for use in the production of foodstuffs.

Herbal Textual Research on Polygonati Rhizoma in Famous Classical Formulas / 中国实验方剂学杂志

By consulting ancient Chinese herbal medicines and medical books， combined with modern documents， the textual research of Polygonati Rhizoma has been conducted to verify the name， origin， bitter-flavored Polygonatum species， Latin name evolution， origin， quality evaluation， harvesting and processing changes， so as to provide reference and basis for the development and utilization of the famous classical formulas. Through textual research， it can be seen that there are many other names for Polygonati Rhizoma， and Huangjing is the correct name since Mingyi Bielu. Based on the original research， it is concluded that P. sibiricum and P. cyrtonema were the mainstream of Polygonati Rhizoma before the Tang dynasty， and P. kingianum was added in the Qing dynasty. According to the shape of medicinal materials， these Polygonatum species were called Jitou Huangjing， Jiangxing Huangjing and Dahuangjing. The harvest time of Polygonati Rhizoma is spring and autumn. After harvest， it is steamed and dried in the sun， and its processing method is mainly "nine steaming and nine storms". Bitter-flavored Polygonatum is mainly P. cirrhifolium， P. zanlanscianense， P. curvistylum and P. verticillatum， which are not suitable for medicine. Based on textual research， it is recommended that when developing famous classical formulas and health products with Polygonati Rhizoma as the main raw material， the origin and producing area should be clear and fixed， and P. sibiricum or P. cyrtonema with clear origin should be used. It is necessary to conduct germplasm survey and sampling in the producing area， establish a planting base and a traceability system for Polygonati Rhizoma， in order to control the quality and stabilize the efficacy of the products. The processing method of Polygonati Rhizoma can be determined according to the product function positioning.

Mechanism of Combination of Pungent Dispersing Bitter Evacuant in Treatment of Asthma Based on Theory of Five Flavor Compatibility / 中国实验方剂学杂志

Bronchial asthma， a chronic inflammatory airway disease， belongs to the category of wheezing disease in the system of traditional Chinese medicine （TCM）. The wheezing symptom of this disease is mainly caused by the imbalance of lung Qi. According to the theory of five flavor compatibility， the Chinese medicinal materials with five different flavors （pungent， bitter， sour， sweet， and salty） can be combined to produce new functions. The pungent medicinal materials have dispersing effect and the bitter medicinal materials have discharging effect， which are important components in the theory of five flavor compatibility. Pungent herbs and bitter herbs can relieve the adverse lung Qi， occupying an important position in the current medication for the treatment of asthma. However， there is still a lack of in-depth analysis of the TCM theory and mechanism of the compatibility of pungent herbs and bitter herbs in the treatment of asthma. The molecular mechanisms of action of pungent herbs and bitter herbs are closely related to transient receptor potential （TRP） channels and bitter taste receptors （TAS2Rs）， respectively. Ca2+ signaling has been recognized in the process of asthma and is involved in the development of multiple symptoms of asthma. The TRP channels and TAS2Rs located on the cell membrane have been proved to directly regulate the intracellular Ca2+ signal and play a role in the treatment of asthma. Therefore， the dispersing effect of pungent herbs and the discharging effect of bitter herbs may be realized through the Ca2+ signaling pathway mediated by TRPs/TAS2Rs. We summarized the theoretical understanding and modern studies of pungent herbs dispersing lung Qi and bitter herbs discharging lung Qi， aiming to explain the internal relationship and mechanism of the compatibility of pungent herbs and bitter herbs in the treatment of asthma from the perspective of TCM theory and modern medicine. The compatibility of pungent herbs and bitter herbs based on the theory of five flavor compatibility for the treatment of asthma has a solid theoretical basis of TCM， and its mechanism can be verified by modern research. Therefore， it may be a main research direction in the treatment of asthma by Chinese medicinal herbs in the future.

Are taste variations associated with the liking of sweetened and unsweetened coffee?

OBJECTIVE: In this study, we evaluated the influence of taste phenotypes and genotypes on the hedonics of sweetened and unsweetened coffee. METHODS: Liking of espresso coffee from food questionnaire and of a ready-to-drink unsweetened coffee beverage was measured using a 9-point hedonic scale in 1551 Italian individuals. Perception and liking for different bitter and sweet compounds were also collected. Genotyping of selected Single Nucleotide Polymorphisms (SNPs) in five taste genes (TAS1R3, GNAT3, TAS2R14, TAS2R19, TAS2R38) was performed. Linear and logistic regression models, including sex and gender as covariates, were used to test the relationship of taste phenotypes and selected SNPs with coffee liking. RESULTS: We found that increased caffeine bitterness perception was associated with an increasing liking for sweetened coffee (p-value = 0.018) and decreased liking of unsweetened coffee (p-value = 0.034). The liking of unsweetened coffee beverage was also negatively associated with sweet intensity perception (p-value = 0.03). Analysis of SNPs in taste-related genes showed that rs6467192 G allele (intron 4 variant) in GNAT3 sweet taste gene was associated with higher liking of sweetened coffee (p-value = 0.002) and lower liking of unsweetened coffee (p-value = 0.01). An association also emerged between unsweetened coffee and SNPs in bitter receptor genes, with rs2597979 in TAS2R14 gene associated with liking of unsweetened coffee (p-value = 0.004) and rs10772420 in TAS2R19 gene associated with liking of both unsweetened espresso coffee and coffee beverage (p-value = 0.04 and p-value = 0.03, respectively). CONCLUSION: These findings suggested that individual preference for sweetened and unsweetened coffee may be influenced by both phenotypic and nucleotide variations in bitter and sweet taste sensitivity.

Therapeutic potential of targeting intestinal bitter taste receptors in diabetes associated with dyslipidemia.

Intestinal release of incretin hormones after food intake promotes glucose-dependent insulin secretion and regulates glucose homeostasis. The impaired incretin effects observed in the pathophysiologic abnormality of type 2 diabetes have triggered the pharmacological development of incretin-based therapy through the activation of glucagon-like peptide-1 (GLP-1) receptor, including GLP-1 receptor agonists (GLP-1 RAs) and dipeptidyl peptidase 4 (DPP4) inhibitors. In the light of the mechanisms involved in the stimulation of GLP-1 secretion, it is a fundamental question to explore whether glucose and lipid homeostasis can be manipulated by the digestive system in response to nutrient ingestion and taste perception along the gastrointestinal tract. While glucose is a potent stimulant of GLP-1 secretion, emerging evidence highlights the importance of bitter tastants in the enteroendocrine secretion of gut hormones through activation of bitter taste receptors. This review summarizes bitter chemosensation in the intestines for GLP-1 secretion and metabolic regulation based on recent advances in biological research of bitter taste receptors and preclinical and clinical investigation of bitter medicinal plants, including bitter melon, hops strobile, and berberine-containing herbs (e.g. coptis rhizome and barberry root). Multiple mechanisms of action of relevant bitter phytochemicals are discussed with the consideration of pharmacokinetic studies. Current evidence suggests that specific agonists targeting bitter taste receptors, such as human TAS2R1 and TAS2R38, may provide both metabolic benefits and anti-inflammatory effects with the modulation of the enteroendocrine hormone secretion and bile acid turnover in metabolic syndrome individuals or diabetic patients with dyslipidemia-related comorbidities.

Bitter Melon Extract Yields Multiple Effects on Intestinal Epithelial Cells and Likely Contributes to Anti-diabetic Functions.

The intestines have been recognized as important tissues for metabolic regulation, including glycemic control, but their vital role in promoting the anti-diabetic effects of bitter melon, the fruit of Momordica charantia L, has seldom been characterized, nor acknowledged. Evidence suggests that bitter melon constituents can have substantial interactions with the intestinal epithelial cells before circulating to other tissues. We therefore characterized the effects of bitter melon extract (BME) on intestinal epithelial cells. BME was found to contain substantial amounts of carbohydrates, proteins, and triterpenoids. TNF-α induced insulin resistance in an enterocyte cell line of IEC-18 cells, and BME promoted glucose utilization of the insulin-resistant cells. Further analysis suggested that the increased glucose consumption was a result of the combined effects of insulin sensitizing and insulin substitution functions of BME. The functions of insulin substitution were likely generated due to the activation of AMP-activated protein kinase. Meanwhile, BME acted as a glucagon-like peptide 1 (GLP-1) secretagogue on enteroendocrine cells, which may be mediated by the activation of bitter-taste receptors. Therefore, BME possesses insulin sensitizing, insulin substitution, and GLP-1 secretagogue functions upon intestinal cells. These effects of BME on intestinal cells likely play a significant part in the anti-diabetic action of bitter melon.

[Review of taste masking techniques in Chinese patent medicine].

Single herbs and Chinese patent medicine preparations often have bad taste, such as bitterness and astringency, which is one of the key factors affecting patients' medication compliance, and would affect the therapeutic effect and restrict the extensive application in clinical practice. Therefore, how to make use of taste masking techniques to improve the bad taste of traditional Chinese medicines has become an important project. Through the collection and summarization of Chinese and foreign journals and papers in recent years, this paper discussed the generation mechanism of bitter taste, the new methods of masking bitter taste and the evaluation me-thods of bitter taste, in order to provide references for the taste masking of Chinese patent medicines preparations.