Investigation of phenolic compounds at the leaves and shoots Arctostaphylos spp. and their antioxidant and antityrosinase activities.

Comparative phytochemical and pharmacological analysis of leaves and shoots of Arctostaphylos uva-ursi (L.) Spreng. and endemic of Transcaucasia and North Caucasia Arctostaphylos caucasica Lipsch. was carried out. Phenolic compounds in methanol extracts were investigated by HPLC-PDA-ESI-MS. Pharmacological investigation was carried out at the models of generation of superoxide, DPPH, hydroxyl and nitrosyl radicals. The antityrosinase properties were evaluated in the reaction of tyrosinase inhibition using L -tyrosine as a substrate. Five new compounds were identified in the shoots and leaves of A. uva-ursi: 4,6-di-О-galloylglucose; 2,3-di-О-galloylglucose; 1,4,6-tri-О-galloylglucose; 1,2,4,6-tetra-О-galloylglucose; tetra-О-galloylhexose. Thirty-five phenolic compounds and two saponins were identified for the first time in A. caucasica. Water-alcohol extract (70% ethanol) from A. caucasica had the highest antiradical activity. Water extracts from both species had antityrosinase activity and possessed comparable efficiency (IC50 = 36.4 ± 1.2 µg/ml and IC50 = 35,5 ± 2 µg/ml, respectively).

Genistein: An Integrative Overview of Its Mode of Action, Pharmacological Properties, and Health Benefits.

Genistein is an isoflavone first isolated from the brooming plant Dyer's Genista tinctoria L. and is widely distributed in the Fabaceae family. As an isoflavone, mammalian genistein exerts estrogen-like functions. Several biological effects of genistein have been reported in preclinical studies, such as the antioxidant, anti-inflammatory, antibacterial, and antiviral activities, the effects of angiogenesis and estrogen, and the pharmacological activities on diabetes and lipid metabolism. The purpose of this review is to provide up-to-date evidence of preclinical pharmacological activities with mechanisms of action, bioavailability, and clinical evidence of genistein. The literature was researched using the most important keyword "genistein" from the PubMed, Science, and Google Scholar databases, and the taxonomy was validated using The Plant List. Data were also collected from specialized books and other online resources. The main positive effects of genistein refer to the protection against cardiovascular diseases and to the decrease of the incidence of some types of cancer, especially breast cancer. Although the mechanism of protection against cancer involves several aspects of genistein metabolism, the researchers attribute this effect to the similarity between the structure of soy genistein and that of estrogen. This structural similarity allows genistein to displace estrogen from cellular receptors, thus blocking their hormonal activity. The pharmacological activities resulting from the experimental studies of this review support the traditional uses of genistein, but in the future, further investigations are needed on the efficacy, safety, and use of nanotechnologies to increase bioavailability and therapeutic efficacy.