Hepatocellular carcinoma(HCC)is one of the most common tumor types and remains a major clinical challenge.Increasing evidence has revealed that mitophagy inhibitors can enhance the effect of chemotherapy on HCC.However,few mitophagy inhibitors have been approved for clinical use in humans.Pyrimethamine(Pyr)is used to treat infections caused by protozoan parasites.Recent studies have reported that Pyr may be beneficial in the treatment of various tumors.However,its mechanism of action is still not clearly defined.Here,we found that blocking mitophagy sensitized cells to Pyr-induced apoptosis.Mechanistically,Pyr potently induced the accumulation of autophagosomes by inhibiting autophagosome-lysosome fusion in human HCC cells.In vitro and in vivo studies revealed that Pyr blocked autophagosome-lysosome fusion by upregulating BNIP3 to inhibit synaptosomal-associated protein 29(SNAP29)-vesicle-associated membrane protein 8(VAMP8)interaction.Moreover,Pyr acted synergistically with sorafenib(Sora)to induce apoptosis and inhibit HCC proliferation in vitro and in vivo.Pyr enhances the sensitivity of HCC cells to Sora,a common chemotherapeutic,by inhibiting mitophagy.Thus,these results provide new insights into the mechanism of action of Pyr and imply that Pyr could potentially be further developed as a novel mitophagy inhibitor.Notably,Pyr and Sora combination therapy could be a promising treatment for malignant HCC.

The present study was designed to determine the chemical constituents of Delphinium caeruleum Jacq. ex Camb.. The chemical constituents were isolated and purified by column chromatography with silica gel, ODS, and Sephadex LH-20. Their structures were elucidated by IR, MS, and NMR. Ten compounds were obtained and identified as caerudelphinine A (1), lycoctonine (2), talitine B (3), talitine A (4), talitine C (5), tatsienine-V (6), d-magnoflorine (7), 2-trimethyl-ammonio-3-(3-indolyl) propionate (8), vakhmatine (9), and delatisine (10). Compound 1 was a new lycoctonine-type C19-diterpenoid alkaloid, and compounds 4-10 were isolated from this plant for the first time.
Aconitine ; analogs & derivatives ; chemistry ; isolation & purification ; Alkaloids ; chemistry ; isolation & purification ; Aporphines ; chemistry ; isolation & purification ; Delphinium ; chemistry ; Diterpenes ; chemistry ; isolation & purification ; Magnetic Resonance Spectroscopy ; Molecular Structure ; Plant Components, Aerial ; chemistry ; Plant Extracts ; chemistry

Objective Throush identify biochemical characteristics and virulence factors of 2 strains suspected Yersinia pestis(Y.pestis)isolated from the dead Marmota himalayana(M.himalayana)to confirm the nature epidemic focus in Dege County,Sichuan Province.Methods Y.pestis was analyzed by specific staining and shape,culturing characteristics,splitting-test by bacteriophage,test of biochemical characteristics and glycolysis ability,virulence factors,virulence,nutritional requirement,plasmid,genetic test and genetic type. Results The tested strains were Gram staining bacilus.The main biochemical characteristics were Arabinose(+)、 Rhamnose(-),Maltose(+),Melibiose(-),Glycerol(+),Denitrification(+).The virulence factors with FI+.VW+, Pgm+,Pst I+;and with the common 6.0×106,45.0×106,65.0×106 plasmids,also with the virulence-relative plasmid gene.Both their absolutely lethal dose(LD100)in mice were 50 bacteria.The nutritional requirement appeared which were depended on Phenylalanine and Methionine.With the Genomovar 5 genotype characteristics of M.himalayana plague foci of Qinghai-Tibet plateau.The difference between tested strains and Yersinia pseudotubercuosis on the 3 different culture medium was obvious.The tested strains had a Y.pestis' specific 3a fragment,Pst I and FI-Ag,at 22 ℃,the strains could be split by bacteriophage completely.Conclusions According to the diagnostic criteria of plague in China,the 2 suspected strains isolated from Dege County,Sichuan Province ale confirmed as Y.pestis.both with powerful virulenceand with the characteristics of the Y.pestis of M.himahtyana in Qinghai-Tibet plateau plague natural focus.