No abstract

9-Dehydro-17-hydro-andrographolide (DHA) and sodium 9-dehydro-17-hydro-andrographolide-19-yl sulfate (DHAS) are active ingredients of xiyanping injection in clinical use. A simple, rapid and sensitive UHPLC-ESI-MS/MS method was developed for the determination of DHA and DHAS in rat plasma, and the pharmacokinetics of DHA and DHAS after intravenous administration of xiyanping injection was investigated. The plasma samples were treated with methanol to precipitate out protein, and the separation of DHA and DHAS was achieved on a Waters BEH C18 column with a mobile phase consisting of acetonitrile and 10 mmol/L ammonium acetate solution at a flow rate of 0.4 mL/min. DHA, DHAS and the internal standard (internal standard, IS) diethylstilbestrol were detected at negative ion mode. The precursor-product ion pairs used in multiple reaction monitoring mode were: m/z 349.1 → 286.9 (DHA), m/z 428.9 → 96.0 (DHAS) and m/z 267.1 → 236.9 (IS). Calibration curves offered satisfactory linearity within the test range, and all correlation coefficients were >0.995. The lower limit of detection of DHA and DHAS in plasma samples were determined to be 0.1 ng/mL. The lower limit of quantitation was 0.5 ng/mL for DHA and DHAS. All the recoveries of the quality control samples were in the range of 86.0-102.4%. The ratios of matrix effect were between 89.2 and 105.1%. The method was fully validated and successfully applied to the pharmacokinetic study of DHA and DHAS in rats. The study showed that both DHA and DHAS were distributed and eliminated rapidly in rats.

The sun is the energy source for living organisms and the earth.Regarding human health, solar radiation exerts most of its positive effects by activating 7-dehydrocholesterol to synthesize Vitamin D 3 in human skin epidermis to prevent osteomalacia. In addition, nitric oxide (NO) production induced by ultraviolet (UV) helps to reduce blood pressure and is anti-bacterial. Exposure to UV rays can improve one's mood by inducing the release of endorphins.Solar UV radiation is divided into three categories based on wavelength, namely UVA (400-315 nm), UVB (315-280 nm) and UVC (280-100 nm). 1 UVC rays are dispersed and reduced by the ozone layer and do not reach the ground. About 90%-99% of UVA and 1%-10% of UVB rays reach the earth's surface. The epidermis of the skin serves as a barrier to protect the body from the external environment. 2 Nonetheless, chronic exposure or intermittent over-exposure of human skin to UV rays leads to various skin diseases, including immunosuppression, irreversible skin photoaging and dermal pathologies, including tumorigenesis. Sunscreen is the

The growth inhibitory effects of garlic polysaccharide (GPS) combined with