Tea and tea drinking: China's outstanding contributions to the mankind.

BACKGROUND: Tea trees originated in southwest China 60 million or 70 million years ago. Written records show that Chinese ancestors had begun drinking tea over 3000 years ago. Nowadays, with the aging of populations worldwide and more people suffering from non-communicable diseases or poor health, tea beverages have become an inexpensive and fine complementary and alternative medicine (CAM) therapy. At present, there are 3 billion people who like to drink tea in the world, but few of them actually understand tea, especially on its development process and the spiritual and cultural connotations. METHODS: We searched PubMed, Google Scholar, Web of Science, CNKI, and other relevant platforms with the key word "tea", and reviewed and analyzed tea-related literatures and pictures in the past 40 years about tea's history, culture, customs, experimental studies, and markets. RESULTS: China is the hometown of tea, tea trees, tea drinking, and tea culture. China has the oldest wild and planted tea trees in the world, fossil of a tea leaf from 35,400,000 years ago, and abundant tea-related literatures and art works. Moreover, tea may be the first Chinese herbal medicine (CHM) used by Chinese people in ancient times. Tea drinking has many benefits to our physical health via its antioxidant, anti-inflammatory, immuno-regulatory, anticancer, cardiovascular-protective, anti-diabetic, and anti-obesity activities. At the moment, COVID-19 is wreaking havoc across the globe and causing severe damages to people's health and lives. Tea has anti-COVID-19 functions via the enhancement of the innate immune response and inhibition of viral growth. Besides, drinking tea can allow people to acquire a peaceful, relaxed, refreshed and cheerful enjoyment, and even longevity. According to the meridian theory of traditional Chinese medicine, different kinds of tea can activate different meridian systems in the human body. At present, black tea (fermented tea) and green tea (non-fermented tea) are the most popular in the world. Black tea accounts for over 90% of all teas sold in western countries. The world's top-grade black teas include Qi Men black in China, Darjeeling and Assam black tea in India, and Uva black tea in Sri Lanka. However, all top ten famous green teas in the world are produced in China, and Xi Hu Long Jing tea is the most famous among all green teas. More than 700 different kinds of components and 27 mineral elements can be found in tea. Tea polyphenols and theaflavin/thearubigins are considered to be the major bioactive components of black tea and green tea, respectively. Overly strong or overheated tea liquid should be avoided when drinking tea. CONCLUSIONS: Today, CAM provides an array of treatment modalities for the health promotion in both developed and developing countries all over the world. Tea drinking, a simple herb-based CAM therapy, has become a popular man-made non-alcoholic beverage widely consumed worldwide, and it can improve the growth of economy as well. Tea can improve our physical and mental health and promote the harmonious development of society through its chemical and cultural elements.

Efficacy and Mechanism of Active Fractions in Fruit of Amomum villosum Lour. for Gastric Cancer.

Amomi Fructus is the dried ripe fruit of Amomum villosum Lour. (A. villosum). It is a well-known traditional Chinese medicine widely used to treat gastrointestinal diseases, while the efficacy or mechanism of main components in Amomi Fructus on cancer treatment remains unknown. In this study, volatile oil of A. villosum (VOAV), total flavonoids of A. villosum (FNAV) and the other residue of A. villosum (RFAV) were distilled, extracted and separated as different active fractions of A. villosum. The cell toxicity test results indicated that VOAV and FNAV can effectively inhibit the cell growth of MFC cells. Flow cytometry test results confirmed that MFC cells were caused apoptosis after being treated with VOAV, FNAV or RFAV. VOAV, FNAV or RFAV induced MFC cells apoptosis through reactive oxygen species (ROS)-mediated mitochondrial pathway, evident by the increase of endogenous ROS and mitochondrial membrane potential collapse. In addition, FNAV exhibited robust inhibitory effects on MFC tumor growth, and could improve the health status of mice compared to that of mice in 5-FU treated group. To sum up, all the above results suggest that FNAV may be a good candidate for the development of new drugs for the treatment of gastric cancer.

Astragaloside IV protects against hyperglycemia-induced vascular endothelial dysfunction by inhibiting oxidative stress and Calpain-1 activation.

AIMS: Vascular endothelial cells act as a selective barrier between circulating blood and vessel wall and play an important role in the occurrence and development of cardiovascular diseases. Astragaloside IV (As-IV) has a protective effect on vascular endothelial cells, but its underlying mechanism remains unclear. This study is aimed at investigating the effect of As-IV on endothelial dysfunction (ED). METHODS: Male Sprague-Dawley (SD) were injected intraperitoneally with 65 mg/kg streptozotocin (STZ) to induce diabetes and then administered orally with As-IV (40, 80 mg/kg) for 8 weeks. Vascular function was evaluated by vascular reactivity in vivo and in vitro. The expression of calpain-1 and eNOS in the aorta of diabetic rats was examined by western blot. NO production was measured using nitrate reductase method. Oxidative stress was determined by measuring SOD, GSH-px and ROS. RESULTS: Our results showed that As-IV administration significantly improved diabetes associated ED in vivo, and both NAC (an antioxidant) and MDL-28170 (calpain-1 inhibitor) significantly attenuated hyperglycemia-induced ED in vitro. Meanwhile, pretreatment with the inhibitor l-NAME nearly abolished vasodilation to ACh in all groups of rats. Furthermore, As-IV increased NO production and the expression of eNOS in the thoracic aorta of diabetic rats. In addition, the levels of ROS were significantly increased, and the activity of SOD and GSH-px were decreased in diabetic rats, while As-IV administration reversed this change in a concentration-dependent manner. CONCLUSION: These results suggest that As-IV improves endothelial dysfunction in thoracic aortas from diabetic rats by reducing oxidative stress and calpain-1.