Caffeine-free hawk tea lowers cholesterol by reducing free cholesterol uptake and the production of very-low-density lipoprotein.

Medicinal plants show important therapeutic value in chronic disease treatment. However, due to their diverse ingredients and complex biological effects, the molecular mechanisms of medicinal plants are yet to be explored. By means of several high-throughput platforms, here we show hawk tea extract (HTE) inhibits Niemann-Pick C1-like 1 (NPC1L1)-mediated free cholesterol uptake, thereby inducing the transcription of low-density lipoprotein receptor (LDLR) downstream of the sterol response element binding protein 2 (SREBP2) pathway. Meanwhile, HTE suppresses hepatocyte nuclear factor 4α (HNF4α)-mediated transcription of microsomal triglyceride transfer protein (MTP) and apolipoprotein B (APOB), thereby decreasing the production of very-low-density lipoprotein. The catechin EGCG ((-)-epigallocatechin gallate) and the flavonoids kaempferol and quercetin are identified as the bioactive components responsible for the effects on the NPC1L1-SREBP2-LDLR axis and HNF4α-MTP/APOB axis, respectively. Overall, hawk tea works as a previously unrecognized cholesterol-lowering agent in a multi-target and multi-component manner.

Composition and safety evaluation of tea from New Zealand kawakawa (Piper excelsum).

Kawakawa (Piper excelsum) has food, medicinal and cultural importance to the indigenous Maori people of New Zealand, and is being incorporated into a range of commercial food and therapeutic products, including tea. In this study, the chemical compositions of kawakawa fresh leaves, dried leaves for tea, and hot brewed tea, were analysed and compared. The key metabolites were diayangambin, elemicin, myristicin, unidentified lignans and amides. The safety of brewed tea and tea leaves were evaluated in 8 week old Sprague Dawley rats in a 14 day acute study followed by a 28 day subacute study. In the 14 day study, the rats received the equivalent of 1, 2, 3 or 4 cups of kawakawa tea, and the rats in the 28 day study received daily doses that were equivalent to 4 cups per day. There were no adverse effects observed in the rats, and body weights and food intakes were not significantly different between the control and the kawakawa treated animals. There were small differences in organ weights, biochemical and haematology parameters observed in the rats given the kawakawa tea. In conclusion, the consumption of kawakawa tea could be considered safe within the conditions used in this study.

Functional Teas from the Stems of Penthorum chinense Pursh.: Phenolic Constituents, Antioxidant and Hepatoprotective Activity.

Penthorum chinense Pursh (PCP), a medicinal and edible plant, is traditionally used for liver protection and treatment of liver diseases. In this study, we compared the differences of composition and activity of flowers, stems and leaves of PCP to select a bioactive part. The stems of PCP with stronger antioxidant activity (6.25-100 µg/mL) and lower cytotoxicity (25-200 µg/mL) than the flowers and leaves were a better bioactive part. Then the chemical composition and hepatoprotective effects of an aqueous extract and an 70% ethanolic extract made with stems of PCP were investigated. We found that the 70% ethanolic extract enriched more polyphenols and flavonoids and possessed significantly stronger hepatoprotective activity than the aqueous extract in the dose range of 25-200 µg/mL, which indicated that 70% ethanol is the better solvent of PCP in extraction technology. Moreover, ethyl acetate extract of stems of PCP (PSE) was used to evaluate the hepatoprotective ability of PCP against oxidative damage using an in vitro model of a normal rat's liver cell (BRL-3A). Besides, 12 phenolic compounds were identified from PSE by ultra-performance liquid chromatography followed by electrospray ionization mass spectrometry (UPLC-ESI-MS). Obtained results strongly support the traditional use of PCP and prove stems of PCP to be an important source of bioactive compounds associated with hepatoprotective activity.

Elemental characterisation of the medical plant Alchemilla velebitica.

Alchemilla, commonly called "lady's mantle", is a genus of herbaceous perennial plants belonging to the family Rosaceae. The species Alchemilla velebitica is found only in Southern Europe, like in the Croatian National Park Northern Velebit. Its benefits, such as a astringent and emmenagogue activity as well as wound healing are correlated to the organic compounds found in the plant, but also certain trace elements are known to reduce skin lesions, such as zinc, selenium, copper, manganese, silicon and lithium. Thus the objective of the present study was the elemental characterization of leaves, blossoms and roots of A. velebitica. After acidic microwave assisted digestion the concentrations of selected essential and trace elements were determined by inductively coupled plasma--atomic emission spectrometry and inductively coupled plasma--mass spectrometry. Other minor elements, such as Al, B, Cu, Fe, Mn, Sr and Zn are also found in leaves, blossoms and roots with contents in µg/kg range. The preparation of decoctions and the extraction yields of the elements of interest are calculated.