High-resolution Tandem Mass Spectrometry for Studying Chemical Constituents of Gynura bicolor DC.

The separation and analysis of the desired chemical components are important subjects for the fundamental research of traditional Chinese medicine (TCM). Ultra-high-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC-Q-TOF-MS/MS) has gradually become a leading technology for the identification of TCM ingredients. Gynura bicolor DC. (BFH), a perennial stemless herb used for medicine and food in China has medicinal effects such as clearing heat, moistening the lung, relieving cough, dispersing stasis, and relieving swelling. Polyphenols and flavonoids contain numerous isomers, which hinder the identification of the complex compounds in BFH. This paper presents a systematic protocol for studying chemical constituents of BFH based on solvent extraction and integrated data via UPLC-Q-TOF-MS. The method described here includes systematic protocols for sample pretreatment, MS calibration, MS acquisition, data processing, and analysis of results. Sample pretreatment includes collection, cleaning, drying, crushing, and extraction. MS calibration consists of multipoint and single-point correction. Data processing includes data importing, method establishment, analysis processing, and result presentation. Representative results of the typical fragmentation pattern of phenolic acids, esters, and glycosides in Gynura bicolor DC. (BFH) are presented in this paper. In addition, organic solvent selection, extraction, data integration, collision energy selection, and method improvement are discussed in detail. This universal protocol can be widely used to identify complex compounds in TCM.

Ethanol extract of Gynura bicolor (GB) protects against UVB-induced photodamage of skin by inhibiting P53-mediated Bcl-2/BAX/Caspase-3 apoptosis pathway.

To investigate the protective effect of ethanol extract of Gynura bicolor (GB) against UVB-induced photodamage of skin and the possible mechanisms. DPPH (1,1-diphenyl-2-pico radical) test was used to detect the antioxidant capacity of ethanol extract of Gynura bicolor (GB). The protective effects of GB against UVB irritation were detected both in Hacat cells and photodamage rat models. UVB irradiation could inhibit viability and induce apoptosis of Hacat cells in a dose-dependent manner. The pretreatment of Hacat cells by GB could obviously reverse the effects in a dose-dependent manner. The mRNA and protein expressions of p53, Bax, caspase-3 were increased, while anti-apoptotic protein Bcl-2 was decreased and this effect could be reversed by GB pretreatment in a dose-dependent manner. In vivo, the application of GB could alleviate the skin damage of SD rats and improve the superficial inflammation of the dermis as well as inhibit the expressions of P53 and Caspase-3 induced by UVB irradiation. Ethanol extract of Gynura bicolor could protect the photodamage of human Hacat keratinocytes and SD rats against UVB irradiation by inhibiting P53-mediated Bcl-2/ BAX/Casaspe-3 apoptosis pathway.