[Research on autophagy induced by two xanthone compounds in HepG2 cells].

To investigate the inhibitory effects of two xanthone compounds, 1-hydroxy-2,3,4,8-4 methoxy xanthone(here in after referred to as Fr15) and 1-hydroxy-2,3,4,6-4 methoxy xanthone(here in after referred to as Fr17), on the proliferation of hepatocellular carcinoma cells HepG2, and to further investigate their mechanism in combination with transcriptomics. Cell counting was used to detect the effects of two kinds of xanthone compounds Fr15 and Fr17(0, 0.03, 0.15, 0.3 mmoL·L~(-1)) on the proliferation of HepG2 cells; the effects of the two compounds Fr15 and Fr17 on HepG2 cell cycle were detected by flow cytometry; the changes of autophagosomes count in cells were observed under fluorescence microscope; the expression of autophagy marker proteins autophagy marker proteins SQSTM 1(p62) and microtubule associated protein 1 light chain 3 Ⅰ/Ⅱ(LC3 Ⅰ/Ⅱ) in the cells was detected by Western blot; the differentially expressed genes between the control group and the experimental group were analyzed by RNA-seq transcriptome sequencing; qRT-PCR was used to verify the differentially expressed genes in sequencing. The results showed that compounds Fr15 and Fr17 inhibited the proliferation of HepG2 cells with the increase of drug concentration and time. Flow cytometry showed that compounds Fr15 and Fr17 had little effect on HepG2 cell cycle. Fluorescence microscopy results showed that the number of autophagosomes in cells increased with the increase of drug concentration. Western blot showed that the expression of p62 protein was decreased and the expression of LC3-Ⅱ protein was significantly increased after drug addition. The results of RNA sequencing showed that 26 102 and 52 351 differentially expressed genes were obtained in Fr15 and Fr17 respectively. Analysis of KEGG showed that drug treatment had a great effect on autophagy pathway. qRT-PCR verified that 6 up-regulated genes were related to autophagy, and their trend was consis-tent with sequencing results, where all 6 genes showed an up-regulated trend. Two xanthone compounds Fr15 and Fr17 may inhibit proliferation of HepG2 cells by inducing autophagy.

Triptolide, A Potential Autophagy Modulator.

As a major active component extracted from traditional Chinese herb Tripterygium wilfordii Hook F, triptolide exhibits multiple pharmacological effects. Autophagy is an evolutionary conserved intracellular catabolic process involved in cytoplasmic materials degradation. Autophagic dysfunction contributes to the pathologies of many human diseases, which makes it a promising therapeutic target. Recent studies have shown that triptolide exerts neuroprotection, anti-tumor activities, organ toxicity, and podocyte protection by modulating autophagy. This article highlights the current information on triptolide-modulated autophagy, analyzes the possible pathways involved, and describes the crosstalk between autophagy and apoptosis modulated by triptolide, in hope of providing implications for the roles of autophagy in pharmacological effects of triptolide and expanding its novel usage as an autophagy modulator.

[Purification and biochemical function of Astragalus membtanaceus pathogenesis-related protein 10].

Astragalus membranaceus pathogenesis-related protein 10 (AmPR-10) is largely expressed in case of environmental pressure and pathogen invasion. This study aims to explore the biochemical functions of AmPR-10. The dried root of Astragalus membranaceus was mechanically homogenized and extracted by Tris-HCl buffer to obtain its crude extract, which was then purified by anion exchange chromatography and gel filtration chromatography to obtain electrophoretically pure AmPR-10. The nuclease activity of AmPR-10 was tested with different RNAs by detecting the absorption value at 260 nm. The results demonstrated potent nuclease activity toward yeast tRNA, yeast RNA, Poly (A) and Poly (C). The optimum reaction temperature was 50 °C and pH was 7-8. EDTA showed no effect on its activity, while Mg²âº exhibited potent activation effect on the activity, and Co²âº, Ca²âº and Zn²âº manifested moderately inhibition of the activity. Since AmPR-10 had no sequence homology with other known nucleases, AmPR-10 was probably a novel nuclease. The inhibition kinetic data against papain was analyzed by Lineweaver-Burk plots, and the results showed that the inhibition of papain followed noncompetitive-type kinetics. AmPR-10 played an important role in Astragalus membranaceus defense mechanism against environmental pressure and pathogen invasion, which may be achieved by inhibiting cycteine enzymes activity.

[Study on triterpenes from of Ligularia xanthotricha].

OBJECTIVE: To investigate the chemical constituents of Ligularia xanthotricha. METHOD: Silica gel column chromatography and preparative TLC were employed for the isolation and purification. The structures were identified on the basis of spectral data (IR, EI-MS, 1H-NMR, 13C-NMR, DEPT) and chemical evidence. RESULT: Seven compounds were isolated and identified as follows: lupeol (1), lupeol palmitate (2), 3, 28-dihydroxyl-lupeol (3), betulinic acid (4), taraxasterol (5), taraxasteryl palmitat (6) and taraxasteryl acetate(7). CONCLUSION: All the compounds were isolated from this plant for the first time.

[Study on chemical constiuents from Ligularia intermedia of shanxi].

OBJECTIVE: To study the chemical constituents of Ligularia intermedia of Shanxi. METHOD: The compounds were isolated by column chromatography on silica gel and preparative TLC. The structures were identified by IR, MS, 1D/2DNMR spectral data and X-ray single crystal diffraction and other methods1. RESULT: Nine compound were isolated and identified as 8beta-hydroxyeremophil-7(11)-ene-12, 8alpha(4beta, 6alpha)-diolide (1), 8beta-methoxyeremophil-7(11)-ene-12, 8alpha(4beta, 6alpha)-diolide (2), petasin (3), isopetasin (4), liguhodgsonal (5), ligudentatol (6), ligujapone (7), lupeol (8) and lupeol palmitate (9). CONCLUSION: Compounds 2, 3, 4, 6, 7 and 9 were isolated from the plant for the first time.