Clinical studies have identified that an excessive exposure of UV light can cause oxidative stress (OS) and tyrosinase enzyme over-expression, which are associated with multiple diseases including atherosclerosis, cancers, diabetics, rheumatoid arthritis. In this study, we investigated the impact of grape seed proanthocyanidin (GSPE) on regulating OS and tyrosinase activity in human epidermal melanocytes. This study revealed that GSPE did not affect cell viability and protected cells from UV induced damage in a dose-dependent manner. 5-(-6)-Carboxy-2,7-di-chlorodihydro-fluorescein diacetate staining (i.e., a fluorescence staining for intracellular (OS)) indicated that GSPE reduced OS level caused by UV exposure. A similar trend was also confirmed by flow cytometry analysis, where GSPE down-regulated OS level. Tyrosinase analysis showed that GSPE treatment decreased tyrosinase activity. Taken all data together, GSPE may restore the cellular damage caused by excessive UV-exposure and promote skin health by reducing tyrosine generation. Clinically, GSPE could be potentially utilized for improving skin health against excessive UV exposure.

In this study, two laboratory-scale simulated landfill bioreactors were established, of which Reactor A was operated only with leachate recirculation and served as the control, and Reactor B was operated as semi-aerobic bioreactor landfill with leachate recirculation. In situ leachate treatment and accelerating organic decomposition in semi-aerobic bioreactor landfill was investigated. The results indicated that the introduction of air into the landfill was favourable for optimising the micro-organism growth environment and accelerating the degradation of organic matter. It can be seen clearly from the results that NH4+-N can be removed in situ in the semi-aerobic bioreactor landfill with leachate recirculation. Moreover, semi-aerobic bioreactor landfill showed lower emissions for leachate than those in leachate from anaerobic landfill, with low concentrations of COD, VFA, NH4+-N and TKN, and which saved the disposing process of the discharged leachate. The three-dimensional excitation-emission matrix fluorescence spectroscopy (EEMs) of dissolved organic matter (DOM) in Reactor B changed greatly, and fluorescence peak changed from protein-like fluorescence at Day 60 to humic-like fluorescence at Day 95 and 250, while in Reactor A, fluorescence peak of DOM was always protein-like fluorescence. The comparison of the EEMs indicated that the semi-aerobic landfill accelerated the organic decomposition.