ABSTRACT
The present study was designed to evaluate protective activity of an ethanol extract of the stems of Schisandra chinensis (SCE) and explore its possible molecular mechanisms on acetaminophen (APAP) induced hepatotoxicity in a mouse model. The results of HPLC analysis showed that the main components of SCE included schisandrol A, schisandrol B, deoxyschisandrin, schisandrin B, and schisandrin C and their contents were 5.83, 7.11, 2.13, 4.86, 0.42 mg·g, respectively. SCE extract was given for 7 consecutive days before a single hepatotoxic dose of APAP (250 mg·kg) was injected to mice. Our results showed that SCE pretreatment ameliorated liver dysfunction and oxidative stress, which was evidenced by significant decreases in aspartate transaminase (AST), alanine aminotransferase (ALT), malondialdehyde (MDA) contents and elevations in reduced glutathione (GSH) and superoxide dismutase (SOD) levels. These findings were associated with the result that the SCE pretreatment significantly decreased expression levels of 4-hydroxynonenal (4-HNE) and 3-nitrotyrosine (3-NT). SCE also significantly decreased the expression levels of Bax, mitogen- activated protein kinase (MAPK), and cleaved caspase-3 by APAP exposure. Furthermore, supplementation with SCE suppressed the expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), suggesting alleviation of inflammatory response. In summary, these findings from the present study clearly demonstrated that SCE exerted significant alleviation in APAP-induced oxidative stress, inflammation and apoptosis mainly via regulating MAPK and caspase-3 signaling pathways.
Subject(s)
Animals , Humans , Male , Mice , Acetaminophen , Alanine Transaminase , Metabolism , Apoptosis , Aspartate Aminotransferases , Metabolism , Caspase 3 , Genetics , Metabolism , Chemical and Drug Induced Liver Injury , Genetics , Metabolism , Drugs, Chinese Herbal , Chemistry , Glutathione , Metabolism , Liver , Metabolism , Malondialdehyde , Metabolism , Mice, Inbred ICR , Mitogen-Activated Protein Kinases , Chemistry , Genetics , Metabolism , Oxidative Stress , Schisandra , Chemistry , Signal TransductionABSTRACT
The present study was designed to evaluate protective activity of an ethanol extract of the stems of Schisandra chinensis (SCE) and explore its possible molecular mechanisms on acetaminophen (APAP) induced hepatotoxicity in a mouse model. The results of HPLC analysis showed that the main components of SCE included schisandrol A, schisandrol B, deoxyschisandrin, schisandrin B, and schisandrin C and their contents were 5.83, 7.11, 2.13, 4.86, 0.42 mg·g, respectively. SCE extract was given for 7 consecutive days before a single hepatotoxic dose of APAP (250 mg·kg) was injected to mice. Our results showed that SCE pretreatment ameliorated liver dysfunction and oxidative stress, which was evidenced by significant decreases in aspartate transaminase (AST), alanine aminotransferase (ALT), malondialdehyde (MDA) contents and elevations in reduced glutathione (GSH) and superoxide dismutase (SOD) levels. These findings were associated with the result that the SCE pretreatment significantly decreased expression levels of 4-hydroxynonenal (4-HNE) and 3-nitrotyrosine (3-NT). SCE also significantly decreased the expression levels of Bax, mitogen- activated protein kinase (MAPK), and cleaved caspase-3 by APAP exposure. Furthermore, supplementation with SCE suppressed the expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), suggesting alleviation of inflammatory response. In summary, these findings from the present study clearly demonstrated that SCE exerted significant alleviation in APAP-induced oxidative stress, inflammation and apoptosis mainly via regulating MAPK and caspase-3 signaling pathways.
Subject(s)
Animals , Humans , Male , Mice , Acetaminophen , Alanine Transaminase , Metabolism , Apoptosis , Aspartate Aminotransferases , Metabolism , Caspase 3 , Genetics , Metabolism , Chemical and Drug Induced Liver Injury , Genetics , Metabolism , Drugs, Chinese Herbal , Chemistry , Glutathione , Metabolism , Liver , Metabolism , Malondialdehyde , Metabolism , Mice, Inbred ICR , Mitogen-Activated Protein Kinases , Chemistry , Genetics , Metabolism , Oxidative Stress , Schisandra , Chemistry , Signal TransductionABSTRACT
ObjectiveTo clarify the influence of human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein 120 V4 region with mutations at amino acid locuses on its abilities to enter target cells.Methods Based on the facts that ADA strains was a CCR5-tropic strain,only had the ability to infect CCR5 cells; that HXB2 strains was a CXCR4-tropic strain,only had the ability to infect CXCR4 cells,serial glycoprotein 120 mutants with alanine substitution in V4 region of ADA and HXB2 strains,were constructed by overlaping PCR.Eukaryotic expression vectors of mutants and expression vectors of HIV framework gene with luciferase reporter gene were cotransfected into eukaryotic cells to produce pseudoviruse.Concentration of HIV-1 gag P24 in pseudoviruses was detected by enzyme-linked immunosorbent assay(ELISA).U87.CD4.CCR5 and U87.CD4.CXCR4 cells were infected with 20 and 40 ng pseudoviruses,with wild ADA and HXB2 strains as control groups,respectively.The ability to infect cells of pseudovirus of each mutant with HIV-1 V4- region mutated at amine acid locuses 386-417 was measured by detecting the luciferase activity (relative light unit,RLU).ResultsTen mutants with alanine substitution in V4 region of HIV-1 ADA and HXB2 strains were successfully constructed,respectively.Mutants of pseudoviruse with 20 ng and 40 ng at locuses 389-391 and 414-417 with alanine substitution of V4 region in both ADA and HXB2 strains lost completely the abilities to enter CCR5 and CXCR4 expressing cells[ (0 ± 0)％].It was found that introduction of alanine to ADAs 400-403 and ADAs 408-410 increased the ability to infect cells to (124 ± 35)％,(182 ± 29)％ and (127 ± 8)％,( 134 ± 16)％ with pseudoviruse of 20 ng and 40 ng,respectively.Likewise,the ability to infect CXCR4 expressing cells also increased to (144 ± 42 )％ and (121 ± 18 )％ with pseudoviruse of 20 ng and 40 ng,respectively by introduction of alanine to HXB2s 395-397.However,other mutants in V4 region of ADA and HXB2 only maintained partial entry abilities( 15％- 84％).ConclusionsMutants of V4 region of HIV-1 envelope glycoprotein 120 with alanine substitution at locuses 389-391 and 414-417 in both ADA and HXB2 strains have been constructed successfully.They completely lost the ability to enter target cells.