Fangjun Lin

Background: Sex differences in physiology have garnered significant interest of late; however, comparatively little is known about the effects of sex on the function of the peripheral taste system. Previously, we have shown that fat taste functions in a sexually dimorphic manner using molecular, cellular, and behavioral assays, and that a subtype of estrogen receptor (ER) proteins is highly expressed in Type II (receptor) cells. The underlying mechanisms of estrogen’s action, though, remain unknown. Objective: Here, we sought to better understand estrogen’s role in fat taste transduction at the molecular level by initially focusing on the transient receptor potential channel types M4 (Trpm4) and M5 (Trpm5), which we have shown to play roles in estrogen-sensitive fatty acid signaling in taste cells. Methods/Results: Using a multidisciplinary approach, using Trpm5-deficient mice, electrophysiological and calcium imaging assays revealed that there are significantly reduced FA responses in both males and females in the estrus phase, whereas females in the proestrus phase did not show this, suggesting that there may be E2-dependent TRPM5-independent FA signaling in Type II cells. During periods of high levels of circulating estrogen, there was no significant difference in cellular responses to fatty acid (FA) stimuli between Trpm5^−/− mice and their wild-type counterparts. Moreover, supplemental estradiol enhanced linoleic acid (LA)-induced TRPM5-mediated taste cell activation. Finally, while Type II cells depend on TRPM4 and TRPM5 for FA taste cell activation, proestrus (high-estrogen) females showed a greater dependence on a TRPM5-independent pathway for fatty acid responsiveness. Conclusions: Together, these results underscore the substantial regulatory role of estrogen in the taste system, particularly for fatty acid signaling. Given that the taste system guides food preferences and intake, these findings may have important implications for understanding sex-specific differences in diet and, ultimately, metabolic health.

Our review systematically outlines the bioactivity and industrial applications of key functional compounds in roses, with a particular focus on their potential in food and pharmaceutical industries from technical, economic, and commercialization perspectives. We summarize the evidence supporting the efficacy of rose-derived polyphenols, flavonoids, and essential oils in areas including antioxidant, anti-inflammatory, antibacterial, and neuroprotective effects, which provide a scientific basis for their use in functional foods and preventive medicines. We further evaluated the commercial viability of processing rose by-products. Additionally, we analyze current and potential applications of rose bioactive compounds in natural food preservatives, functional dietary supplements, herbal medicines, and cosmetic products. Finally, we discuss the remaining challenges and future directions for the industrial utilization of roses, including standardization, efficacy validation in humans, and scalable economic models, to facilitate the transition from experimental research to commercially sustainable applications.

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.

We previously reported that the adiponectin receptor agonist AdipoRon selectively enhances cellular responses to fatty acids in a human taste cell line. The enhancement role of AdipoRon on fatty acid-induced cell responses is mediated by the activation of AMPK and translocation of CD36 on human taste cells. It has also been shown that 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. 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. 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 the human taste cells, the enhancement role of AdipoRon on fatty acid-induced responses was impaired by the co-administration of an AMPK inhibitor (Compound C) or a CD36 inhibitor (SSO). Utilizing Adipor1-deficient animals we determined 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.

Adiponectin, a key metabolic hormone, is secreted into the circulation by fat cells where it enhances insulin sensitivity and stimulates glucose and fatty acid metabolism. Adiponectin receptors are highly expressed in the taste system; however, their effects and mechanisms of action in the modulation of gustatory function remain unclear. We utilized an immortalized human fungiform taste cell line (HuFF) to investigate the effect of AdipoRon, an adiponectin receptor agonist, on fatty acid-induced calcium responses. We showed that the fat taste receptors (CD36 and GPR120) and taste signaling molecules (Gα-gust, PLCβ2, and TRPM5) were expressed in HuFF cells. Calcium imaging studies showed that linoleic acid induced a dose-dependent calcium response in HuFF cells, and it was significantly reduced by the antagonists of CD36, GPR120, PLCβ2, and TRPM5. AdipoRon administration enhanced HuFF cell responses to fatty acids but not to a mixture of sweet, bitter, and umami tastants. This enhancement was inhibited by an irreversible CD36 antagonist and by an AMPK inhibitor but was not affected by a GPR120 antagonist. AdipoRon increased the phosphorylation of AMPK and the translocation of CD36 to the cell surface, which was eliminated by blocking AMPK. These results indicate that AdipoRon acts to increase cell surface CD36 in HuFF cells to selectively enhance their responses to fatty acids. This, in turn, is consistent with the ability of adiponectin receptor activity to alter taste cues associated with dietary fat intake.

Onion (Allium cepa L.) is a common vegetable, widely consumed all over the world. Onion contains diverse phytochemicals, including organosulfur compounds, phenolic compounds, polysaccharides, and saponins. The phenolic and sulfur-containing compounds, including onionin A, cysteine sulfoxides, quercetin, and quercetin glucosides, are the major bioactive constituents of onion. Accumulated studies have revealed that onion and its bioactive compounds possess various health functions, such as antioxidant, antimicrobial, anti-inflammatory, anti-obesity, anti-diabetic, anticancer, cardiovascular protective, neuroprotective, hepatorenal protective, respiratory protective, digestive system protective, reproductive protective, and immunomodulatory properties. Herein, the main bioactive compounds in onion are summarized, followed by intensively discussing its major health functions as well as relevant molecular mechanisms. Moreover, the potential safety concerns about onion contamination and the ways to mitigate these issues are also discussed. We hope that this paper can attract broader attention to onion and its bioactive compounds, which are promising ingredients in the development of functional foods and nutraceuticals for preventing and managing certain chronic diseases.

The zebrafish is a species of freshwater fish, popular in aquariums and laboratories. Several advantageous features have facilitated zebrafish to be extensively utilized as a valuable vertebrate model in the lab. It has been well-recognized that natural products possess multiple health benefits for humans. With the increasing demand for natural products in the development of functional foods, nutraceuticals, and natural cosmetics, the zebrafish has emerged as an unprecedented tool for rapidly and economically screening and identifying safe and effective substances from natural products. This review first summarized the key factors for the management of zebrafish in the laboratory, followed by highlighting the current progress on the establishment and applications of zebrafish models in the bioactivity evaluation of natural products. In addition, the zebrafish models used for assessing the potential toxicity or health risks of natural products were involved as well. Overall, this review indicates that zebrafish are promising animal models for the bioactivity and safety evaluation of natural products, and zebrafish models can accelerate the discovery of novel natural products with potential health functions.

The ability of mammalian taste cells to respond to fatty acids (FAs) has garnered significant attention of late and has been proposed to represent a sixth primary taste. With few exceptions, studies on FA taste have centered exclusively on polyunsaturated FAs, most notably on linoleic acid. In the current study, we have identified an additional FA receptor, GPR84, in the gustatory system that responds to the medium-chain saturated FAs (MCFAs) in male mice. GPR84 ligands activate both Type II and Type III taste cells in calcium imaging and patch-clamp recording assays. MCFAs depolarize and lead to a rise in intracellular free [Ca²⁺] in mouse taste cells in a concentration-dependent fashion, and the relative ligand specificity in taste cells is consistent with the response profile of GPR84 expressed in a heterologous system. A systemic Gpr84^−/− mouse model reveals a specific deficit in both the neural (via chorda tympani recording) and behavioral responses to administration of oral MCFAs compared with WT mice. Together, we show that the peripheral taste system can respond to an additional class of FAs, the saturated FAs, and that the cognate receptor necessary for this ability is GPR84.

Ficus pumila L. has been used as a functional plant for a long time in East Asia, especially its fruits, as a dietary component in Japan and parts of China. A series of bioactive compounds, including phenolic acids, flavonoids, terpenoids, alcohols, and steroids, have been extracted from the stems, leaves, flowers, and fruits of Ficus pumila L. Accumulated studies have demonstrated that Ficus pumila L. has multiple therapeutic activities, including antioxidant, anti-inflammatory, antibacterial, antitumor, hypoglycemic, and cardiovascular protective effects. Moreover, Ficus pumila L. has extensive applications, such as in the food industry and ecological city construction. Herein, we summarize the latest knowledge about the bioactive compounds and therapeutic activities of Ficus pumila L., and its applications in the food industry and ecological city construction are also discussed. We hope that this comprehensive review can attract more attention to Ficus pumila L. and be helpful for its further applications.