Objective To preliminarily explore the early process of hepatitis B virus (HBV) infection in HepG2 cells induced by dimethyl sulfoxide(DMSO) ,and provide cytological bases for mechanism study of HBV infection in vitro .Methods HepG cells were divided into the DMSO inducing group and control group ,and were cultured 4 days by DMEM containing 1 .5% DMSO and normal DMEM respectively ;changes of cellular morphology were observed .In addition ,selected ECV304 cells as the negative con‐trol group and treated with DMSO .Cells in the three groups were incubated 2 hours with HBV positive serum after culturing 24 hours ,then trypsin digestive solution ,HepG2 cells and ECV304 cells were collected and polymerase chain reaction (PCR) was used for the determination of HBV DNA .Simultaneously ,the blank control group was set ,and the position of HBsAg on HepG2 cells were detected by using indirect immunofluorescence .Results HepG2 cell volume in the DMSO inducing group was obviously in‐creased .HBV DNA was found in HepG2 cells both in DMSO inducing group and control group ,and DMSO inducing group ex‐pressed much stronger .The results of IIF shown that green fluorescent signals of cell membrane and cytoplasm of HepG 2 cells in the DMSO inducing group were increased obviously ,while the results of HBV DNA and IIF both were negative in the negative con‐trol group .Conclusion DMSO could facilitate adsorption of HBsAg in some extent ,which are benefit for completing the process of early infection .

Danshen, the dried roots and rhizomes of Salvia miltiorrhiza Bunge (S. miltiorrhiza), is widely used in the treatment of cardiovascular and cerebrovascular diseases. Tanshinones, the bioactive compounds from Danshen, exhibit a wide spectrum of pharmacological properties, suggesting their potential for future therapeutic applications. Tanshinone biosynthesis is a complex process involving at least six P450 enzymes that have been identified and characterized, most of which belong to the CYP76 and CYP71 families. In this study, CYP81C16, a member of the CYP71 clan, was identified in S. miltiorrhiza. An in vitro assay revealed that it could catalyze the hydroxylation of four para-quinone-type tanshinones, namely neocryptotanshinone, deoxyneocryptotanshinone, and danshenxinkuns A and B. SmCYP81C16 emerged as a potential broad-spectrum oxidase targeting the C-18 position of para-quinone-type tanshinones with an impressive relative conversion rate exceeding 90%. Kinetic evaluations andin vivo assays underscored its highest affinity towards neocryptotanshinone among the tested substrates. The overexpression of SmCYP81C16 promoted the accumulation of (iso)tanshinone in hairy root lines. The characterization of SmCYP81C16 in this study accentuates its potential as a pivotal tool in the biotechnological production of tanshinones, either through microbial or plant metabolic engineering.
Humans ; Salvia miltiorrhiza/metabolism* ; Biosynthetic Pathways ; Quinones/metabolism* ; Plant Roots/metabolism* ; Gene Expression Regulation, Plant