ABSTRACT
Objective To development a cooling crystallization process that is suitable for industrial preparation of purified dihydromyricetin.Methods Screen design was used to investigate effects of process parameters such as,temperature,concentration ethanol aqueous,quantity of activated charcoal and adsorption time on yield and purity of dihydromyricetin.Purity was verified by high performance liquid chromatography and thin layer chromatography.The solubility of dihydromyricetin in water at viable temperature and ethanol proportion was also determined by UV spectrophotometry.The solid form was characterized by thermal analysis and powder X-ray diffractometry.Results When temperature was ＞ 85 ℃,ethanol concentration ＜ 10％,dosage of activated charcoal 0.1％-0.3％,and adsorption time 1-3 min,yield of dihydromyricetin was more than 70％,and the purity greater than 98％.The crystals,prepared by cooling crystallization from water and ethanol aqueous,had the same physical form and crystal habit.Conclusion Cooling crystallization from low concentration of ethanol aqueous gets higher yield and the process is more robust than crystallization from water.
ABSTRACT
s:Apoptosis, also known as programmed cell death, is a gene controlled active cell suicide process in order to maintain balance of organisms. Apoptosis is mainly mediated through three signal pathways, including the endoplasmic reticulum, mitochondria, and death receptor. As a kind of naphthoquinone compounds and one of the main active ingredients of Lithospermum, shikonin has many biological activities, and its anti-cancer research is recent hot spot. The anti-cancer mechanism of shikonin is closely related with apoptosis and three kinds of signaling pathways. This article reviewed the research progress in apoptosis and signal pathways induced by shikonin.
ABSTRACT
Objective To explore the effects of volatile oil and 2-undecanone from Houttuynia Cordata Thunb. (H. cordata) on LPS-TLR4 / MD-2-TNF-α signaling pathway. Methods TLR4 / MD-2 blocking agent was used to mask the TLR4 /MD-2 site,then protein expression levels of TLR4 in cells treated with volatile oil and 2-undecanone were analyzed by western blot. ELISA was used to detect the secretion of the inflammatory cytokines such as TNF-α,IL-1β and IL-10. Comparison analysis was then performed from the results of cell experiments in vitro and anti-inflammatory effects through xylene-induced ear edema test in vivo. Results In concentrations between 1 to 10 μg · mL-1 ,Houttuynia volatile oil showed better effect than 2-undecanone on inhibition of TLR4 protein in LPS-induced RAW264. 7 cells, and had some differences in the effects on inflammatory factors. Compared with the LPS+TLR4 / MD-2 group,the LPS+TLR4 / MD-2 + volatile oil group had no significant difference in the expression of TLR4 protein (P>0. 05),but the LPS+TLR4 / MD-2 +2-undecanone group reduced the expression of TLR4 protein obviously. It appeared that volatile oil exerts its anti-inflammatory effect through LPS-TLR4 / MD-2-TNF-αpathway,but 2-undecanone may exert its anti-inflammatory effect by other means. Houttuynia volatile oil showed better anti-inflammatory activity than 2-undecanone in vivo at the same dose. Conclusion There are some differences in anti-inflammatory effects and related mechanisms between volatile oil and 2-undecanone, probably owing to the synergistic effects of multi-ingredients in the volatile oil.