Search Results (92)

Red Fruit Ginseng (Campanumoea lancifolia), widely cultivated in Yunnan, Guizhou, Sichuan, and Guangxi, in China, is valued for its sweet-tasting fruit and medicinal potential. In this study, leaves of the Yunnan Maguan variety were used as explants to establish an efficient tissue culture system for callus induction, adventitious bud regeneration, and rooting. Different combinations of cytokinins and auxins were tested to determine the optimal balance of plant growth regulators (PGRs). Our results indicated that when the combined concentration of kinetin (KT) and 6-benzylaminopurine (6-BA) in the primary culture medium was lower than 1.0 mg/L, callus induction was the most effective, with treatments of 0.5 mg/L KT + 0.2 mg/L 6-BA and 0.2 mg/L KT + 0.8 mg/L 6-BA showing higher induction rates compared to other groups. During the subculture, 0.5 mg/L 6-BA promoted vigorous adventitious bud growth, while higher levels inhibited development. For rooting, 0.5 mg/L indole-3-acetic acid (IAA) combined with 0.2 mg/L 1-naphthaleneacetic acid (NAA) induced the highest root number and healthiest plantlets, outperforming indole-3-butyric acid (IBA). The optimized protocol resulted in over 80% explant survival and produced vigorous seedlings suitable for acclimatization. This leaf-derived regeneration method provides a reliable approach for large-scale propagation, conservation, and potential pharmacological applications of Red Fruit Ginseng, contributing to the sustainable utilization and commercial development of this valuable medicinal plant. Full article

The swallowing reflex is a highly coordinated process that is essential for safe bolus transit and airway protection. Although its neurophysiological framework has been extensively studied, the molecular mechanisms underlying reflex initiation remain incompletely understood, limiting targeted therapies for oropharyngeal dysphagia. Recent evidence implicates purinergic signaling as a key mediator of swallowing initiation, particularly through ATP release from taste buds and neuroendocrine cells in the hypopharyngeal and laryngeal mucosa. Experimental studies in mice demonstrate that water, acidic, and bitter chemical stimuli induce ATP release, activating purinergic receptors (P2X2, P2X3, heteromeric P2X2/P2X3, and P2Y1) on afferent sensory fibers. This receptor activation enhances input to the brainstem swallowing central pattern generator, initiating reflexive swallowing. Genetic ablation of purinergic receptor-expressing neurons or epithelial sentinel cells, as well as pharmacological antagonism of P2X or P2X3 receptors, markedly attenuates these responses. Furthermore, exogenous ATP or selective P2X3 agonists applied to swallowing-related mucosa evoke swallowing reflexes in an animal model, underscoring translational potential. While the precise upstream receptor mechanisms for water- and acid-induced ATP release, as well as species-specific differences, remain to be clarified, targeting purinergic pathways may represent a novel physiologically grounded therapeutic strategy for restoring swallowing function in patients with oropharyngeal dysphagia. Full article

Background: Sweet taste adaptation, the decline in perceived sweetness with repeated exposure, may influence dietary behavior and differs across sweeteners. Low-calorie sweeteners (LCSs) such as sucralose strongly activate the T1R2+T1R3 receptor and are generally associated with greater adaptation than sugars, although this effect can be reduced with sweetener blends. Aim: We investigated whether habitual LCS consumption affects sweet taste perception and whether blending sucralose with small amounts of sugars attenuates adaptation using sensory tests in humans and in vivo calcium imaging in a rodent model. Methods: In study 1, habitual (HC; n = 39) and non-habitual (NHC; n = 42) LCS consumers rate sweetness of sucralose (0.6 mM), glucose (800 mM), fructose (475 mM), and blends with low glucose (111 mM) or fructose (45 mM) across repeated trials (1–10) using a generalized labeled magnitude scale. In study 2, a microfluidic-based intravital tongue imaging system was used to assess in vivo responses to sweet adaptation in genetically modified C57BL/6 mice (n = 8) expressing a calcium indicator in type II/III cells of taste buds. Results: Habitual LCS use was not associated with differences in sweetness perception or adaptation (all p-values > 0.6). Sucralose alone produced stronger adaptation than when blended with sugars in both humans (p-values < 0.002) and mice (p < 0.001). Glucose and fructose alone showed adaptation (relative decrease reached on final trial compared to the first trial: −27% ± 4% for glucose, −38% ± 5% for fructose, both p-values < 0.002) but to a lower degree compared with sucralose (−66% ± 5%). Conclusions: Sweetener composition, rather than habitual LCS use, drives sweet taste adaptation. Blending sucralose with small amounts of sugars reduces adaptation at both perceptual and cellular levels, providing mechanistic insights relevant to the formulation of LCS products. Full article

Litchi (Litchi chinensis Sonn.) is a kind of evergreen fruit tree with good flavor and taste which has high economic value. Sufficiently low temperature in winter is essential for the successful flower formation of litchi. Therefore, in the context of global warming, litchi often experiences unstable flower formation, ultimately resulting in a decrease in litchi production. Our previous research has highlighted the pivotal role of the LcFT1 gene in regulating the flower formation of litchi and identified two AP1 homologous genes associated with LcFT1 (named LcAP1-1 and LcAP1-2) based on RNA-Seq and weight gene co-expression network analysis (WGCNA). In this study, the functions of the two AP1 homologous genes in regulating flowering time were investigated. Result showed that LcAP1-1 and LcAP1-2 were expressed in all litchi tissues. LcAP1-1 was more highly expressed in mature leaves compared to other tissues, while the LcAP1-2 has the highest expression level in flower buds. Both of them exhibited upregulation in the terminal bud of litchi under low temperature. The expression of LcAP1-1 and LcAP1-2 was highly correlated with the initiation of flower buds and the development of flower organs. They increased gradually during the floral initiation but decreased gradually during flower bud development. The transgenic tobacco of LcAP1-2 flowered about 55 days earlier than wild-type, while tobacco overexpressing the LcAP1-1 gene had no significant changes in flowering time compared to the wild-type. These results indicate that the two genes have divergent regulatory functions, and that the LcAP1-2 gene may be involved in the regulation of flower transformation and flower organ development in litchi. Our research will further reveal the molecular regulatory mechanisms of flower formation in litchi and will also provide theoretical guidance for the molecular breeding of litchi. Full article

Background: Taste disorders in patients with type 2 diabetes mellitus (T2DM) have a negative impact on their quality of life and glycemic control, and treatment options are limited. Buzhong yiqi formula (BZYQF) improves T2DM symptoms but its effects on T2DM-induced taste disorders have not been sufficiently studied. Methods: Molecular docking was utilized to evaluate binding activity between the compounds in BZYQF and the sweet taste receptors (STRs). T2DM was induced in rats through the administration of high-fat diet and streptozotocin, and the rats were then treated with BZYQF for 8 weeks. Daily indicators and serum biochemical factors were monitored. Taste preferences for sweet, bitter, salty, and sour solutions were assessed using a two-bottle test. The morphology of lingual papillae and the numbers of taste buds were examined using HE staining. A high-glucose (HG) model of taste bud organoids was established to measure sucrose-evoked ATP release. The expression of signaling molecules in the sweet taste receptors (STRs) pathway was determined via RT-qPCR, Western blot, and immunofluorescence in lingual papillae and organoids. Results: A total of 508 compounds in BZYQF indicated good binding activity to T1R2, T1R3 or heterodimers of T1R2/T1R3, and 60 compounds had good binding activity to all three forms of STRs. BZYQF alleviated T2DM symptoms and improved taste perception for maltose (10 mM, 50 mM), quinine (0.03 mM, 0.1 mM), and citric acid (1 mM) solutions. BZYQF improved the morphological structure of lingual papillae and increased taste bud numbers in T2DM rats. BZYQF enhanced ATP release responses to sucrose solution in the taste bud organoids of the HG model. Gene expression determination showed that BZYQF upregulated the expression of signaling molecules in the STRs pathway (T1R2, T1R3, IP3R, α-gustducin, TRPM5) in the lingual papillae of the T2DM rats and in the taste bud organoids of the HG model. Conclusions: BZYQF alleviates T2DM-induced taste disorders by increasing the numbers of taste buds and upregulating STR signaling molecules, in which various compounds, especially flavonoids, exhibit a synergistic effect. Full article

Umami taste compounds are perceived in broilers through taste buds that detect peptides and amino acids, which can positively or negatively affect their feeding behavior. In this study, we evaluated the intake behavior for four essential amino acids (Lysine, Methionine, Threonine, and Tryptophan) in chickens. Sixty-four one-day-old male birds (Ross 308) were used. For 16 days during the early stage of the birds, two-choice preference tests were performed, in which 16 combinations composed of four amino acids in four concentrations (0.1 to 1.5%) diluted in water were evaluated, which were supplied in contrast to the delivery of water (a neutral compound) to a pair of birds in a pen for 4 h of administration after a prior 1 h fast. Amino acid solutions such as Threonine and Tryptophan tended to show less preference at the highest exposed concentrations (1.5%) concerning drinking water, which was confirmed in the case of Threonine when performing a sensory-motivated intake analysis (SMI). The opposite occurred with Lysine (1.5%), which numerically showed a higher preference ratified by SMI and acceptability analysis concerning water and other concentrations of the same amino acid, respectively. When palatability was measured with pecking cluster size, no significant differences across amino acid concentrations were observed, which is probably attributed to short recording periods and differences in solution intake behavior between chickens and previous experimental models such as rats. The results reinforce the notion that it is necessary to standardize feeding behavior tests in birds according to their feeding patterns and nutritional needs. Full article

Capparis spinosa is an edible plant with a long history in the Mediterranean region since antiquity. Its flower buds and leaves are mostly consumed salted or fermented (in vinegar) and are rarely eaten raw or dried. For the first time, caper samples subjected to different preservation processes (dried, salted, and desalted) were studied, foraged from the most producing Cycladic islands in Greece (Sifnos, Serifos, and Tinos). The quantitative determination of the flavonoids rutin and quercetin was carried out using high performance thin-layer chromatography (HPTLC), revealing the abundance of rutin in the buds and leaves (9.26–76.85 mg/g dry extract). Only one sample of desalted buds from Serifos showed a sufficient amount of quercetin (2.88 mg/g dry extract). The determination of total phenolic content (TPC) showed a decrease during brine (salted) preservation (11.7–37.7 mg GAE/g extract) compared to air-dried samples (50.9–62.4 mg GAE/g extract). The DPPH evaluation (8.0–35.2% inhibition at 200 μg/mL) was in agreement with the TPC results. All extracts showed stronger activity against Gram positive bacteria and the human pathogenic fungi C. glabrata. The samples from Sifnos exerted better bioactivities, with air-drying being the most effective preservation process in terms of antioxidant properties and phenolic content, although it resulted in a more bitter taste. Due to its high economic value, the caper holds great potential for further exploitation through better established and optimized processes in the food industry. Full article

Background: Obesity is associated with the altered gustatory perception of dietary fatty acids. Celastrol, a triterpene, has been demonstrated to exert anti-obesity effects in rodents. We assessed the role of Celastrol in the modulation of the oro-sensory perception of lipids in control and high-fat diet (HFD)-induced obese mice. Methods: Male mice of the C57B/6J strain were fed a HFD for 11 weeks and then were administered or not with Celastrol further for 4 weeks. The body weight was recorded weekly. Before the sacrifice, the animals were subjected to oro-sensory detection of a dietary long-chain fatty acid in a two-bottle choice paradigm. After the sacrifice, the fungiform taste buds were isolated and analyzed for mRNA expression, encoding fat sensors (CD36 and GPR120) and pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α). Circulating concentrations of IL-6 and TNF-α were also determined, and liver was used to analyze the mRNA expression of lipogenic genes. Results: Celastrol administration in obese mice decreased body weight and also re-established the loss of oro-sensory perception for a dietary fatty acid, and this phenomenon was, in part, due to the upregulation of mRNA, encoding fat taste receptors (CD36 and GPR120) in tongue taste bud cells. Furthermore, Celastrol decreased inflammation both in taste buds and blood circulation. Conclusions: Our findings suggest that Celastrol decreases body weight gain, ameliorates the gustatory perception of lipids, and downregulates inflammation in obese mice. Full article

Background/Objectives: Taste guides the consumption of food and alcohol for both humans and rodents. Given that chronic dietary exposure to bitter and sweet foods are purported to alter the perception of bitter and sweet tastes respectively, we hypothesized that dietary habits may shape how the taste properties of ethanol are perceived and thus how it is consumed. Methods: Using C57BL/6 mice as a model, we contrasted taste behavior, morphology, and expression after a 4-week diet featuring consistent bitter, sweet, or neutral (water) stimuli. Results: Our results demonstrated that a 4-week bitter diet containing a quinine solution increased preference for ethanol, while a 4-week sweet diet consisting of a sucralose solution did not alter ethanol preference nor intake. The quinine diet also reduced the number of sweet- or umami-sensing T1R3-positive cells in the circumvallate papillae taste buds of the mice. Conclusions: Based on the behavioral changes observed with the bitter diet, it is possible that either bitter or sweet taste, or both together, drive the increase in ethanol preference. The implications of these findings for alcohol consumption are that dietary habits that do not necessarily concern alcohol may be capable of altering alcohol preference via taste habituation. Habitual intake of bitter and/or sweet foods can shift the perception of taste over time. Changes to how the taste components of alcohol are perceived may also alter how acceptable the taste of alcohol is when experienced as a whole, thereby having the unintended consequence of shifting alcohol consumption levels. Our study demonstrates another side to bitter habituation, which, thus far, has been studied in the more positive context of developing a set of dietary tactics for promoting bitter vegetable intake. Full article

Flavonoids are secondary metabolites that are beneficial to life activities and are mainly concentrated in buds and leaves in the form of glycosides. Flavonoid glycosides have important effects on the properties and quality of tea plants. Research has shown that the abundance of flavonoid glycosides varies greatly among different cultivars, but research on the regulatory mechanisms that cause their differential accumulation among tea plant cultivars with different leaf colors is lacking. In this study, an integrated analysis of metabolomics and transcriptomics was conducted to determine the regulatory networks regulating astringency and color-related flavonoids in tea plant cultivars with diverse leaf colors. A total of five anthocyanidins, four catechins, and nine flavonol glycosides were found to partially contribute to the differences in taste and leaf color among tea plant cultivars with diverse leaf colors. Furthermore, 15 MYB genes and 5 Dof genes were identified as potential regulators controlling the expression of eight key structural genes, resulting in differences in the accumulation of specific compounds, including epicatechin (EC), catechin (C), cyanidin, cyanidin 3-O-glucoside, pelargonidin 3-O-glucoside, and quercetin 3-O-glucoside, in tea plant cultivars with diverse leaf colors. These findings provide insights into the development and utilization of resources from tea plants with diverse leaf colors. Full article

Vertebrates’ tongues reflect part of their adaptations to diverse feeding strategies, the types of food items they eat, and the environments where they live. Our contribution was to analyze the macro- and microscopic morphology of the tongues of two porpoise species (Phocoena dioptrica and Phocoena spinipinnis; juveniles and adults), whose biology is little known. Macroscopic and microscopic studies (conventional histology, scanning electron microscopy, immunohistochemistry, and morphometry) were performed. Differences between juvenile and adult individuals of the same species, as well as between juveniles and adults of both species, were found, probably related to their feeding and/or geographical distribution. In addition, novel aspects related to ontogenetic morphological differences, thermoregulation, and immune system components were described. We found a lingual countercurrent vascular system (periarterial venous retia), only mentioned for mysticetes and Physeter macrocephalus (never for smaller odontocetes). In addition, we identified mechanoreceptors (lamellar corpuscles). Both species showed marginal papillae, but only in P. spinipinnis were small (probably vestigial) taste buds observed. Finally, lingual lymphoid aggregates were found. Full article

Bitter taste perception is crucial for animal survival. By detecting potentially harmful substances, such as plant secondary metabolites, as bitter, animals can avoid ingesting toxic compounds. In vertebrates, this function is mediated by taste receptors type 2 (T2Rs), a family of G protein-coupled receptors (GPCRs) expressed on taste buds. Given their vital roles, T2Rs have undergone significant selective pressures throughout vertebrate evolution, leading to frequent gene duplications and deletions, functional changes, and intrapopulation differentiation across various lineages. Recent advancements in genomic and functional research have uncovered the repertoires and functions of bitter taste receptors in a wide range of vertebrate species, shedding light on their evolution in relation to dietary habits and other ecological factors. This review summarizes recent research on bitter taste receptors and explores the mechanisms driving the diversity of these receptors from the perspective of vertebrate ecology and evolution. Full article

Background/Objectives: Taste dysfunction is a frequent symptom of acute coronavirus disease (COVID)-19 caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). While the majority of those affected reported recovery over time, emerging data suggest that 20–25% of individuals experience persistent taste dysfunction, constituting a common symptom of long COVID. Gustation is mediated by continuously renewing taste bud cells. A balance between the counteracting processes of cell generation and cell death maintains the homeostatic turnover. Sonic hedgehog (SHH) is a morphogenic protein that promotes taste cell proliferation and differentiation. Enzymatic proteins such as gustin modulate the environment around the taste receptors and influence taste perception. Hence, we hypothesized that increased taste cell turnover and reduced taste-related salivary proteins contribute to the taste dysfunction in long COVID. Methods: Unstimulated whole saliva (UWS) was collected from individuals with long COVID experiencing taste dysfunction after obtaining informed consent. The normal control included archived saliva samples catalogued prior to 2019. Taste perception was objectively determined by the waterless empirical taste test. The SHH, gustin, and inflammatory cytokines in UWS were determined with ELISA. The expressions of epithelial and taste-cell-specific markers in cellular saliva were assessed by immunoflurorescence. Results: Impaired bitter taste was the most common dysfunction in the long-COVID cohort. Salivary gustin was significantly lower in those with long COVID and correlated with lower bitter taste score. Cellular saliva showed keratin-10- and small-proline-rich protein-positive epithelial cells as well as SHH-, occluding- and KCNQ1-positive taste cells. Conclusions: Salivary gustin could be a marker for impaired bitter taste in long COVID. Full article

Grass carp (Ctenopharyngodon idella) is a Cyprinid fish of aquacultural and research importance. The buccal cavity represents the gateway of the digestive tract. The present study investigated the adaptational changes involving various components of the buccal cavity of fingerling (three months posthatching, mph), yearling (12 mph), and adult (48 mph) C. idella using scanning electron microscopy, histology, and morphometry. The upper and lower lips appeared uninterrupted at the three studied stages and were limited caudally by the upper and lower jaws. The jaw epithelium was the thickest part of the buccal epithelium; ultrastructurally, it appeared smooth with ridge-like borders in fingerlings that transformed into microgrooves in yearlings. In adult C. idella, the jaw mucosa was organized into dome-shaped masses separated from each other by tight furrows. Each mass was formed from several keratinocytes with corrugated surfaces that featured numerous microdepressions. Except for the jaws, taste buds, mainly of type I, and acidic and neutral goblet cells were observed throughout the mucosa of the buccal cavity, and their densities were highest along the mucosal folds of the palate and oral floor, suggesting a principal role for these parts in both gustation and food lubrication. This study is the first to report age-associated spatiotemporal changes in the buccal cavity of grass carp and will serve as a fundamental reference during the interpretation of various types of oral pathologies in teleost. Full article

Background/Objectives: Adiponectin, the most abundant peptide hormone secreted by adipocytes, is a well-known homeostatic factor regulating lipid metabolism and insulin sensitivity. It has been shown that the adiponectin receptor agonist AdipoRon selectively enhances cellular responses to fatty acids in human taste cells, and adiponectin selectively increases taste behavioral responses to intralipid in mice. However, the molecular mechanism underlying the physiological effects of adiponectin on fat taste in mice remains unclear. Conclusions: Here we define AdipoR1 as the mediator responsible for the enhancement role of adiponectin/AdipoRon on fatty acid-induced responses in mouse taste bud cells. Methods and Results: Calcium imaging data demonstrate that AdipoRon enhances linoleic acid-induced calcium responses in a dose-dependent fashion in mouse taste cells isolated from circumvallate and fungiform papillae. Similar to human taste cells, the enhancement role of AdipoRon on fatty acid-induced responses was impaired by co-administration of an AMPK inhibitor (Compound C) or a CD36 inhibitor (SSO). Utilizing Adipor1-deficient animals, we determined that the enhancement role of AdipoRon/adiponectin is dependent on AdipoR1, since AdipoRon/adiponectin failed to increase fatty acid-induced calcium responses in taste bud cells isolated from these mice. Brief-access taste tests were performed to determine whether AdipoRon’s enhancement role was correlated with any differences in taste behavioral responses to fat. Although AdipoRon enhances the cellular responses of taste bud cells to fatty acids, it does not appear to alter fat taste behavior in mice. However, fat-naïve Adipor1^−/− animals were indifferent to increasing concentrations of intralipid, suggesting that adiponectin signaling may have profound effects on the ability of mice to detect fatty acids in the absence of previous exposure to fatty acids and fat-containing diets. Full article