Insect tea originated from ethnic minority regions in Southwest China: A review on the types, traditional uses, nutrients, chemistry and pharmacological activities.

Abstract

Insect tea is a special non-Camellia tea produced from the feces of insects in ethnic minority regions in Southwest China. Insect tea was recorded to have the traditional functions to treat summer heat, dampness, digestive disturbance, excessive phlegm, shortness of breath and otitis, etc. AIM OF THIS STUDY: This review provides an updated and comprehensive review of insect tea on the tea types, host plants, tea-producing insects, producing process, traditional uses, nutritional values, chemistry, pharmacological activities, biological safety and toxicity. Moreover, the general challenges and the possible suggestions on insect tea in future were also discussed. The relevant literature on insect tea was obtained from scientific database, including Elsevier, PubMed, Springer, Wiley, Web of Science, Google Scholar, SciFinder, China National Knowledge Infrastructure (CNKI), Baidu Scholar, Wanfang Database, etc. In addition, pertinent information available in Ph.D theses, MSc. dissertations, books, records, and some classical Chinese herbal literature were also included. The references cited in this review were up to September 2022. Insect tea has been traditionally used as popular beverage with various medicinal functions in the ethnic minority regions in Southwest China for centuries. At present, ten types of insect teas are recorded in different regions. Ten species tea-producing insect and fifteen species host plants are used to in the production of the tea. Insect teas were rich in various nutrients including proteins, carbohydrates, fat, minerals, dietary fiber and Vitamins. A total of 71 compounds have been isolated from insect teas, mainly including flavonoids, ellagitannins, chlorogenic acids and other phenolic compounds as well as the alkaloids. Modern studies demonstrated that insect tea had a variety of pharmacological activities in vitro and in vivo, such as anti-diabetic, lipid-lowing and anti-hypertensive, hepato-protective, gastro-intestinal promoting, anti-cancer, anti-mutagenic, antioxidant, and anti-aging activity, etc. Moreover, existing experimental results showed that insect teas are non-toxicity and biological safety. Insect tea is a unique and niche product originated in the ethnic minority regions of Southwest China with various health-promoting benefits. Phenolics including flavonoids, ellagitannins, chlorogenic acids were reported as the main chemical constituents identified from insect tea. Multiple pharmacological activities of insect tea have been reported, which indicated that it had great potential for further development and application as drugs and health-promoting products. However, more studies on the tea-producing insects, host plants, chemistry and pharmacological activity of insect tea, as well as the toxicology should be further investigated.