Human bitter taste-sensing type 2 receptors (hTAS2Rs) are expressed in various human tissues and may be associated with various cell signaling pathways, cell progression, and cell physiology in each tissue. hTAS2Rs can be a potential drug target because it is also expressed in some cancer cells. Xanthorrhizol (XNT) has various biological activities, such as anticancer, antimicrobial, anti-inflammatory, and antioxidant. XNT produces a bitter taste, but the specific hTAS2R activated is unknown, and the hTAS2R-mediated effect of XNT on cancer cells has not been studied. This study discovered the target receptor of XNT among 25 hTAS2Rs and confirmed the possibility of the hTAS2R-mediated inhibition of cancer cell proliferation. XNT activated only one receptor, hTAS2R38 (EC50=1.606±0.021 g/mL), and its activity was inhibited by probenecid, a hTAS2R38 antagonist. When HepG2 and MCF-7 cells were treated with XNT or phenylthiocarbamide (PTC), a known hTAS2R38 agonist, both chemicals inhibited cancer cell proliferation. XNT targets the human bitter taste receptor TAS2R38 and inhibits the proliferation of HepG2 and MCF-7 cells mediated by TAS2R38. This suggests that TAS2R38 may be a new target for disease treatment and a potential new factor for drug development.

본고는 한중 미각어 ‘쓰다’, ‘苦’ 계열 어휘를 대상으로 의미 확장 및 개념화 양상에 대해 살펴보는데 목적이 있다. 1차적으로는 사전에 기술된 의미 항목을 대조하고 이를 바탕으로 말뭉치 자료 분석을 통하여 실제 언어생활에서 사용되는 풍성한 표현 양상을 미각, 후각, 시각, 청각, 감정 및 태도, 일·사건, 사람, 날씨 영역 등으로 분류하였다. 더 나아가 이러한 어휘의 의미 구성 과정에 대해 Fauconnier & Turner(1997)에서 제시된 인지언어학의 핵심이론인 개념적 혼성 이론을 이용하여 각 의미의 혼성공간 및 발현구조에 대해 묘사하였다. 이러한 어휘의 의미 확장 과정은 신체적 경험과 매우 밀접한 관계를 맺고 있는데 쓴맛에 대한 우리의 부정적 느낌에 대한 경험이 의미 확장 양상에서도 대부분 부정적 가치로 나타났다. 이처럼 어휘의 의미 확장은 인간의 체험에 근거하며, 또한 개별 언어의 문화적 차이로 인하여 서로 다른 특수성이 존재함을 밝혔다.

Taste is closely related to intake of food. Taste perception is also influenced by type of food ingested, and nutrition and health status. Bitter taste plays an important role in the survival of human and animals to avoid probable toxic and harmful substances. Vertebrate animals recognize bitter taste through type 2 taste receptors (T2Rs). Several T2Rs have been expressed extra-oral such as the gastrointestinal tract, respiratory tract, urogenital tract, brain and immune cells, and parts of their functions are being revealed. This review will discuss physiological roles of T2Rs in relation to innate immunity, secretion and smooth muscle contraction expressed in extra-oral cells and tissues, and we summarize relationships between polymorphisms in T2Rs and general or oral diseases. It is not a coincidence that animals pay much genetic costs for taste and smell during evolution.

Recent findings indicate that Type 2 taste receptors (T2Rs) are expressed outside the gustatory system, including in the gastrointestinal tracts and the exocrine glands, such as the submandibular (SM), parotid (P), lacrimal (L) glands and pancreas (PC). Specifically, T2Rs are found in some of the gastrointestinal endocrine cells, and these cells secreted peptide hormones in response to stimulation by bitter-tasting compounds. The results show that T2Rs may have significant physiological roles besides bitter taste reception. The functions of the T2Rs in the exocrine glands remain poorly understood. An expression levels analysis of T2Rs will help to determine those functions in the exocrine glands. The expression levels of the T2Rs in the exocrine glands were discovered via the qPCR. C57BL/6J mice of 42~60-day-old were used. Messenger RNAs were extracted from S, P, L and PC. Cloned DNAs were synthesized by reverse transcription. Quantitative PCRs were performed using the SYBR Green method. The expression levels of the T2Rs were calculated as relative expression levels to that of the GAPDH. The statistical significance among the observed exocrine glands was tested using the variance analysis (ANOVA test). Tas2r108, out of murine 35 T2Rs, was the most highly expressed in every observed exocrine gland. This finding was similar to previous results from tongue papillae, but the expression levels were lower than those of the tongue papillae. Tas2r137 of SM, P, L and PC were expressed a little lower than that of tongue papillae. The T2Rs in the exocrine glands may play slightly different roles from those in the tongue. We suggest that physiological studies such as a patch clamp and functional Ca2+ imaging of acinar cells are necessary for understanding the Tas2r108 functions.

Mammals have 3 pairs of major salivary glands i.e., the parotid, submandibular, and sublingual glands. Saliva secretion of these glands is modulated by taste perception. Salivary glands are composed mainly of acinar and ductal cells. Primary saliva is secreted by acinar cells and modified during ductal flow. Recently, of the murine 35 bitter taste receptors, Tas2r108 was expressed at highest levels in the submandibular gland by qPCR. Further, Tas2r108-transfected cells respond to a range of bitter compounds, such as denatonium, quinine, colchicine, diphenidol, caffeine and dapson. The objective of the present study was to characterize the expression of Tas2r108 mRNA in acinar and/or ductal cells of the submandibular gland using in situ hybridization (ISH). Male 42-60 days old DBA2 mice were used in the study. Messenger RNAs were extracted from the submandibular gland for generating digoxigenin (DIG) labeled-cRNA probes. These probes were transcribed in anti-sense and sense orientation using T7 RNA polymerase. Dot blot hybridization was performed using DIG labeled-cRNA probes, in order to estimate integrity and optimal diluting concentration of these probes. Subsequently, ISH was performed on murine submandibular gland to detect Tas2r108 mRNA. Dot blot hybridization data demonstrated that Tas2r108 DIG labeled-cRNA anti-sense probes specifically detected Tas2r108 cDNA. ISH results showed that the anti-sense probes labeled acinar and ductal cells in the submandibular gland, whereas no staining was visible in sense controls. Interestingly, the Tas2r108 expression levels were higher in acinar than ductal cells. These results suggested that Tas2r108 might be more associated with primary saliva secretion than with ductal modification of saliva composition.

본 연구에서는 볶음 처리 후 여주의 총 phenolics, 총 flavonoids, 갈변물질(MRPs, maillard reaction products), 항산화 활성 및 α-glucosidase 저해활성을 비교하였다. 또한 alkaloids 유도체와 쓴맛 저감 효과를 평가하였다. 볶음 온도 및 시간이 증가함에 따라 볶음 처리된 여주는 총 phenolics, 총 flavonoids, MRPs, 항산화 활성 및 α-glucosidase 저해활성 역시 증가하였으나, alkaloid계 화합물 및 쓴맛은 감소하였다. 특히 200℃에서 15분 동안 볶은 여주는 총 phenolics, 총 flavonoids, MRPs, 항산화 활성 및 α-glucosidase 저해활성이 가장 높았고 alkaloid계 화합물 및 쓴맛은 가장 낮게 나타났다. 이 결과로부터 볶음 여주는 쓴맛이 저감되고 이들 추출물은 식품에서도 잠재적인 천연 항산화제로 사용할 수 있을 것으로 판단되었다.

The nasal cavity encounters various irritants during inha¬lation such as dust and pathogens. To detect and remove these irritants, it has been postulated that the nasal mucosa epithelium has a specialized sensing system. The oral cavity, on the other hand, is known to have bitter taste receptors (T2Rs) that can detect harmful substances to prevent ingestion. Recently, solitary chemosensory cells expressing T2R subtypes have been found in the respiratory epithelium of rodents. In addition, T2Rs have been identified in the human airway epithelia. However, it is not clear which T2Rs are expressed in the human nasal mucosa epithelium and whether they mediate the removal of foreign materials through increased cilia movement. In our current study, we show that human T2R receptors indeed function also in the nasal mucosa epithelium. Our RT-PCR data indicate that the T2R subtypes (T2R3, T2R4, T2R5, T2R10, T2R13, T2R14, T2R39, T2R43, T2R44, T2R 45, T2R46, T2R47, T2R48, T2R49, and T2R50) are expressed in human nasal mucosa. Furthermore, we have found that T2R receptor activators such as bitter chemicals augments the ciliary beating frequency. Our results thus demonstrate that T2Rs are likely to function in the cleanup of inhaled dust and pathogens by increasing ciliary movement. This would suggest that T2Rs are feasible molecular targets for the development of novel treatment strategies for nasal infection and inflammation.

Background : Bitter gourd (Momordica charantia) is a vegetable with pantropical distribution and contains the active ingredient, such as momordicine and charantin. Moreover, bitter gourd has been reported to exhibit antidiabetic, anticancer, cardiovascular-protective and antioxidant effects. But, the distinctive bitter taste of bitter gourd was not suitable for food preference. This study was conducted to evaluate the improvement effects of bitter taste of bitter gourd with natural fermentation and roasting process. Methods and Results : Bitter gourd fruits were obtained from Headeulnyeokae Co., Ltd.(Gang-Jin 59253, Repubilc Korea). Fruits of bitter gourd were prepared by natural fermentation process for 4h at 25℃. After natural fermentation, the fruits were dried in hot-air dryer for 15h at 49-55℃. The dried fruits were roasted in 500 g batches at 120℃ for 10 min in the electric rotisserie oven. After roasting, fruit pieces were extracted with hot water and cold water. One of them was cool-type, and the other was hot-type bitter gourd tea. In the sensory evaluation, hot tea and cold tea showed the high scores on color, flavor and overall acceptability. Conclusion : These mean that roasted bitter gourd had less bitter, and it could be utilized widely as drink and food material.