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Crocetin is an aglycone of crocin naturally occurring in saffron and produced in biological systems by hydrolysis of crocin as a bioactive metabolite. It is known to exist in several medicinal plants, the desiccative ripe fruit of the cape jasmine belonging to the Rubiaceae family, and stigmas of the saffron plant of the Iridaceae family. According to modern pharmacological investigations, crocetin possesses cardioprotective, hepatoprotective, neuroprotective, antidepressant, antiviral, anticancer, atherosclerotic, antidiabetic, and memory-enhancing properties. Although poor bioavailability hinders therapeutic applications, derivatization and formulation preparation technologies have broadened the application prospects for crocetin. To promote the research and development of crocetin, we summarized the distribution, preparation and production, total synthesis and derivatization technology, pharmacological activity, pharmacokinetics, drug safety, drug formulations, and preparation of crocetin.

This study reported the isolation and characterization of 11 rifamycin congeners including six new ones (1–6) from the agar fermentation extract of Amycolatopsis mediterranei S699. Compounds 1 and 2 are rifamycin glycosides named as rifamycinosides A and B, respectively. Their polyketide skeleton represents a novel cleavage pattern of the rifamycin ansa chain. Compounds 6 and 8 showed potential T3SS inhibitory activity, and 6 induced G2/M phase arrest and caused DNA damage in HCT116 cells.

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High altitude cerebral edema (HACE) is a high altitude malady caused by acute hypobaric hypoxia (AHH), in which pathogenesis is associated with oxidative stress and inflammatory cytokines. Potentilla anserina L is mainly distributed in Tibetan Plateau, and its polysaccharide possesses many physiological and pharmacological properties. In the present study, the protective effect and potential treatment mechanism of Potentilla anserina L polysaccharide (PAP) in HACE were explored. First, we measured the brain water content and observed the pathological changes in brain tissues, furthermore, malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), and glutathione (GSH) were evaluated by kits. Finally, the protein contents and mRNA expressions of pro‐inflammatory (IL‐1β, IL‐6, TNF‐α, vascular endothelial cell growth factor [VEGF], NF‐κB, and hypoxia inducible factor‐1 α [HIF‐1α]) were detected by ELISA kits, RT‐PCR, and western blotting. The results demonstrated that PAP reduced the brain water content, alleviated brain tissue injury, reduce the levels of MDA and NO, and increased the activity of SOD and GSH level. In addition, PAP blocking the NF‐κB and HIF‐1α signaling pathway activation inhibited the generation of downstream pro‐inflammatory cytokines (IL‐1β, IL‐6, TNF‐α, and VEGF). Therefore, PAP has a potential to treat and prevent of HACE by suppression of oxidative stress and inflammatory response.

Background. Hypoxia exerts pressure on cells and organisms, and this pressure can occur under both pathological and nonpathological conditions. There are many reports confirmed that hydroxytyrosol has good in vitro antioxidant activity, while the research about hydroxytyrosol on hypoxia-mediated cell damage is still unclear. Purpose. The aim of this study was to investigate the effect and mechanism of hydroxytyrosol on hypoxia-mediated cell damage. Methods. We studied the effects of hydroxytyrosol on the content of reactive oxygen species, the change of antioxidant enzymes activity of SOD, CAT, and GSH-Px and the content of oxidation products MDA and GSH, and the changes of cell membrane potential and effect on PI3K/AKT/mTOR-HIF-1α signaling pathway under hypoxia-mediated PC12 cell. Results. PC12 cell treated with hydroxytyrosol abated the cell apoptosis and alleviated the oxidative stress through scavenging of reactive oxygen species, improving the enzyme activity and changing the content of oxidation products and alleviating mitochondria damage. Western blotting confirmed that the mechanism maybe related to the PI3K/AKT/mTOR-HIF-1α signaling pathway. The inhibition experiment confirmed that hydroxytyrosol takes part in the expression of protein PI3K and p-mTOR. Conclusion. Hydroxytyrosol reduced the oxidative stress and resisted the inhibition of PI3K/AKT/mTOR-HIF-1α signaling pathway caused by hypoxia, improved cell apoptosis, and ameliorated the antihypoxia ability of PC12 cells under hypoxia.

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