Chemical composition, sensory qualities, and pharmacological properties of primary leaf hawk tea as affected using different processing methods

Tibetan tea consumption prevents obesity by modulating the cellular composition and metabolic reprogramming of white adipose tissue

Obesity, a global health concern, is linked with numerous metabolic and inflammatory disorders. Tibetan tea, a traditional Chinese beverage rich in theabrownin, is investigated in this study for its potential anti-obesity effects. Our work demonstrates that Tibetan tea consumption in C57BL/6J mice significantly mitigates obesity-related phenotypic changes without altering energy intake. Computational prediction revealed that Tibetan tea consumption reconstructs gene expression in white adipose tissue (WAT), promoting lipid catabolism and thereby increasing energy expenditure. We also note that Tibetan tea suppresses inflammation in WAT, reducing adipocyte hyperplasia and immune cell infiltration. Furthermore, Tibetan tea induces profound metabolic reprogramming, influencing amino acid metabolic pathways, specifically enhancing glutamine synthesis, which in turn suppresses pro-inflammatory chemokine production. These findings highlight Tibetan tea as a potential candidate in obesity prevention, providing a nuanced understanding of its capacity to modulate the cellular composition and metabolic landscape of WAT.

Preliminary exploration of herbal tea products based on traditional knowledge and hypotheses concerning herbal tea selection: a case study in Southwest Guizhou, China

BACKGROUND

Herbal tea usually refers to "beverage plants that do not belong to the genus Camellia", and it holds a significant historical legacy as a traditional beverage among specific regions and ethnic groups. In light of this, our research aims to investigate and analyze the traditional knowledge pertaining to herbal tea plants used by local people in the Qianxinan Buyi and Miao Autonomous Prefecture, Guizhou Province. We also initiated preliminary efforts to create tea products from herbal tea leaves using various processing techniques. Additionally, we attempted to test hypotheses to elucidate how local people select herbal tea plants.

METHODS

Data related to the use of herbal tea plants in this study were collected through semi-structured interviews and participatory observations in four villages in Qianxinan. Quantitative indicators, including the relative frequency of citation (RFC) and the relative importance (RI) value, were calculated, and the availability of plants was also evaluated. General linear model was performed to examine the relationship between the frequency of citation and resource availability, as well as the correlation between the relative frequency of citation and the relative importance, to test both the resource availability hypothesis and the versatility hypothesis. Centella asiatica tea was processed using techniques from green tea, black tea and white tea, with a preliminary sensory evaluation conducted.

RESULTS

A total of 114 plant species were documented as being used for herbal teas by local residents, representing 60 families and 104 genera. Of these, 61% of herbal tea plants were found growing in the wild, and 11 species were exotic plants. The family with the highest number of species was Asteraceae (20 species). The study identified 33 major medicinal functions of herbal tea, with clearing heat-toxin and diuresis being the most common functions. General linear model revealed a strong correlation (correlation coefficient of 0.72, p < 0.001) between the frequency of citation and plant availability, as well as a significant correlation (correlation coefficient of 0.63, p < 0.001) between RFC and RI. Under different processing conditions, the characteristics of Centella asiatica tea exhibited variations and were found to be suitable for consumption.

CONCLUSION

The consumption of herbal tea serves as a preventive measure against common ailments for local residents. The resource availability hypothesis, diversification hypothesis and the versatility hypothesis were shown to provide some insight into "how and why local communities select plants for use." Exotic herbal tea plants in the study area also possess valuable therapeutic properties. The processing and production of Centella asiatica herbal tea products hold promising prospects.

Pterostilbene-Loaded Soluplus/Poloxamer 188 Mixed Micelles for Protection against Acetaminophen-Induced Acute Liver Injury

Excessive acetaminophen (APAP) induces excess reactive oxygen species (ROS), leading to liver damage. Pterostilbene (PTE) has excellent antioxidant and anti-inflammatory activities, but poor solubility limits its biological activity. In this study, we prepared PTE-loaded Soluplus/poloxamer 188 mixed micelles (PTE-MMs), and the protective mechanism against APAP-induced liver injury was investigated. In vitro results showed that PTE-MMs protected H₂O₂-induced HepG2 cell proliferation inhibition, ROS accumulation, and mitochondrial membrane potential destruction. Immunofluorescence results indicated that PTE-MMs significantly inhibited H₂O₂-induced DNA damage and cGAS-STING pathway activation. For in vivo protection studies, PTE-MMs (25 and 50 mg/kg) were administered orally for 5 days, followed by APAP (300 mg/kg). The results showed that APAP significantly induced injury in liver histopathology as well as an increase in serum aspartate aminotransferase and alanine aminotransferase levels. Moreover, the above characteristics of APAP-induced acute liver injury were inhibited by PTE-MMs. In addition, APAP-induced changes in the activities of antioxidant enzymes such as SOD and GSH in liver tissue were also inhibited by PTE-MMs. Immunohistochemical results showed that PTE-MMs inhibited APAP-induced DNA damage and cGAS-STING pathway activation in liver tissues. For in vivo therapeutic effect study, mice were first given APAP (300 mg/kg), followed by oral administration of PTE-MMs (50 mg/kg) for 3 days. The results showed that PTE-MMs exhibited promising therapeutic effects on APAP-induced acute liver injury. In conclusion, our study shows that the Soluplus/poloxamer 188 MM system has the potential to enhance the biological activity of PTE in the protection and therapeutic of liver injury.

Hawk Tea Flavonoids as Natural Hepatoprotective Agents Alleviate Acute Liver Damage by Reshaping the Intestinal Microbiota and Modulating the Nrf2 and NF-κB Signaling Pathways

Hawk tea (Litsea coreana Levl. var. lanuginosa) is a traditional herbal tea in southwestern China, and was found to possess hepatoprotective effects in our previous study. However, it is unclear whether hawk tea flavonoids (HTF) can alleviate alcoholic liver damage (ALD). Firstly, we extracted and identified the presence of 191 molecules categorized as HTFs, with reynoutrin, avicularin, guaijaverin, cynaroside, and kaempferol-7-O-glucoside being the most prevalent. After taking bioavailability into consideration and conducting comprehensive sorting, the contribution of guaijaverin was the highest (0.016 mg/mice). Then, by daily intragastric administration of HTF (100 mg/kg/day) to the ALD mice, we found that HTF alleviated liver lipid deposition (inhibition of TG, TC, LDL-C) by reducing liver oxidative-stress-mediated inflammation (up-regulation NRF2/HO-1 and down-regulation TLR4/MyD88/NF-κB pathway) and reshaping the gut microbiota (Lactobacillus, Bifidobacterium, Bacillus increased). Overall, we found HTF could be a potential protective natural compound for treating ALD via the gut–liver axis and guaijaverin might be the key substance involved.

Targeted and untargeted metabolomic analyses and biological activity of Tibetan tea

Tibetan tea is not only a national product of geographical identity, but also a traditional beverage inherits Chinese tradition. This study evaluated the metabolic profiles and biological activity in four Tibetan teas. 83 non-volatile metabolites were identified as differentially expressed metabolites, including amino acids and their derivatives, phenolic acids, flavonoids, nucleotides and their derivatives, terpenes, alkaloids, organic acids, lipids and others. CC and 131 were rich in terpenoids and lipids. MZ contained the highest contents of amino acids and their derivatives, phenolic acids and flavonoids. 26 key volatile compounds were considered as odor-active compounds. MZ showed the highest level of antioxidant and hypoglycemic activity. Statistics analysis indicated that polyphenols, flavonoids and catechins were significantly correlated (|r| ≥ 0.7, P < 0.05) with biological activities. This study indicated significant differences in the metabolic profiles of various types of Tibetan tea, which provided a clear database for quality detection of Tibetan tea.