Phytochemical Characterization ofRhododendron ferrugineumandIn VitroAssessment of an Aqueous Extract on Cell Toxicity

Abstract

Within a systematic phytochemical investigation of the leaves of RHODODENDRON FERRUGINEUM L. (Ericaceae), the volatile oil was isolated (0.7 %) and its constituents were characterized. Eleven flavonoids were isolated and characterized, with quercetin 3- O-[6''- O-(2-methyl-1-oxobutyl)]-β- D-glucopyranoside and 2 R,3 R-dihydromyricetin 3- O- β- L-arabinopyranoside as new natural products. Beside monomeric flavan-3-ols (catechin, epicatechin, gallocatechin, epigallocatechin) from the tannin fraction (about 3.5 % calculated as pyrogallol), the dimeric procyanidins B1 to B7 were identified, as well as the trimeric compounds procyanidin C1, epicatechin-(4 β → 8)-epicatechin-(4 β → 8)-catechin and the trimeric A type-linked cinnamtannin B1. Additionally, phloroacetophenon 4- O- β- D-glucopyranoside and chlorogenic acid were isolated. Water-soluble carbohydrates comprised about 13.5 % of the dried leaves, including fructans (3 %), polysaccharides (1 %) (mainly type II arabinogalactans), glucose, fructose, sucrose, stachyose and raffinose. The IN VITRO effects on cellular vitality (MTT test), proliferation (BrdU incorporation) and necrosis (LDH release) of an aqueous extract were investigated. The extract did not exert any toxic effects, while the vitality and the proliferation rates of epithelial HaCaT keratinocytes were significantly increased at 100 µg/mL, indicating that the aqueous extract does not have negative effects against cellular activity.

Comparison of the polyphenolic profile and antibacterial activity of the leaves, fruits and flowers of Rhododendron ambiguum and Rhododendron cinnabarinum

“…All identified polyphenol compounds have been discovered in nature already [1, 15–26]. Out of the identified compounds, 46 were already reported to be found in Rhododendron species [1, 16–18]. In this study, 13 new polyphenolic compounds were identified in Rhododendron species .…”

Persea americanaMill. Seed: Fractionation, Characterization, and Effects on Human Keratinocytes and Fibroblasts

“…Extracts, cotyledon solvent partitions, and HSCCC fractions of P. americana were solved into a stock solution of 1 mg/mL in Aqua Millipore, sterilized by filtration through a 0.2  μ m regenerated cellulose acetate membrane, and solved in the recommended serum-free media to a final concentration of 10  μ g/mL. As positive control 10% FCS was added to test medium [21]. Incubation started 24 h after seeding when the cells had reached a confluence of 50% and ended 48 h later by adding 5-bromo-2′-deoxyuridine (BrdU), 3-(4, 5-Dimethyl-2-thiazolyl)-2, 5-diphenyl-2H-tetrazolium bromide (MTT), and (4-[3-(4-Iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1, 3-benzene disulfonate (WST-1).…”

In vitro inhibitory effects of dihydromyricetin on human liver cytochrome P450 enzymes

“…Wang (Vitaceae) is a medicinal and edible plant that is widely distributed in southern China, and its tender stem and leaves have been used as a medicinal tea for the prevention and treatment of the common cold, sore throat and icteric viral hepatitis for hundreds of years Bi et al 2016;Chen et al 2016). Dihydromyricetin (DHM) is the most abundant and active flavonoid component isolated from Ampelopsis grossedentata (Du et al 2002;Louis et al 2010;Yin et al 2010;Xia et al 2014;Zhong et al 2014). DHM possesses numerous biological and pharmacological activities, including anti-oxidative, anti-inflammatory, hepatoprotective, lipid and blood glucose regulation, and anticancer effects (Jiang et al 2014;Liu et al 2014;Chen et al 2015;Ji et al 2015;Meng et al 2015).…”