Aim： To determine the cellular distribution of secretory phospholipase A2 （sPLA2） in dependence on the acrosomal state and under the action of elastase released under inflammatory processes from leukocytes. Methods...Aim： To determine the cellular distribution of secretory phospholipase A2 （sPLA2） in dependence on the acrosomal state and under the action of elastase released under inflammatory processes from leukocytes. Methods： Acrosome reaction of spermatozoa was triggered by calcimycin. Human leukocyte elastase was used to simulate inflammatory conditions. To visualize the distribution of sPLA2 and to determine the acrosomal state, immunofluorescence techniques and lectin binding combined with confocal laser scanning fluorescence microscopy and flow cytometry were used. Results： Although sPLA2 was detected at the acrosome and tail regions in intact spermatozoa, it disappeared from the head region after triggering the acrosome reaction. This release of sPLA2 was associated with enhanced binding of annexin V-fluoroscein isothiocyanate （FITC） to spermatozoa surfaces, intercalation of ethidium-homodimer I, and binding of FITC-labelled concanavalin A at the acrosomal region. Spermatozoa from healthy subjects treated with elastase were characterized by release of sPLA2, disturbance of acrosome structure, and loss of vitality. Conclusion： The ability of spermatozoa to release secretory phospholipase A2 is related to the acrosomal state. Premature destabi- lization of the acrosome and loss of sPLA2 can occur during silent inflammations in the male genital tract. The distribution pattern of sPLA2 in intact spermatozoa might be an additional parameter for evaluating sperm quality.展开更多
A novel series of eight SMS and sPLA2 dual inhibitors containing indole and a-amino cyanide fragments of different length and substitution position was synthesized and evaluated by three different in vitro assays. Bio...A novel series of eight SMS and sPLA2 dual inhibitors containing indole and a-amino cyanide fragments of different length and substitution position was synthesized and evaluated by three different in vitro assays. Biological evaluation showed that all compounds provided inhibitory effects against SMS （about 50% inhibition at 100 μmol/L） and sPLA2 （14-32 μmol/L）. All the compounds had the SMS activity better than the positive control compound D609 in SMS2 homogenate, with compounds 5b and fie ideal for liver homogenate and SMS2 high expression cell homogenate, respectively.展开更多
Objective:To evaluate antioxidant,cytotoxic,and anti-venom capacity of crude bark extracts of Alstonia parvifolia Merr.Methods:Gas chromatography-mass spectrometry(GC-MS)and energy dispersive X-ray analyses were accom...Objective:To evaluate antioxidant,cytotoxic,and anti-venom capacity of crude bark extracts of Alstonia parvifolia Merr.Methods:Gas chromatography-mass spectrometry(GC-MS)and energy dispersive X-ray analyses were accomplished to characterize the chemical constituents of Alstonia parvifolia.Biochemical characterization was evaluated using an inhibitory phospholipase A_(2)(PLA_(2))assay,DPPH,and cytotoxicity assays.Using the constituents listed in the GC-MS analyses,molecular docking was conducted to inspect the binding energies between the chosen compounds and selected PLA_(2) isoforms.Results:GC-MS analyses showed that the Alstonia parvifolia crude extract consisted predominantly of acetylmarinobufogenin(14.89%),γ-sitosterol(10.44%),3-O-methyl-D-glucose(5.88%),3,5-dimethoxy-4-hydroxyphenylacetic acid(5.30%),(2α,5α)-17-methoxyaspidofractinin-3-one(AFM)(4.08%),and 2,3,5,6,7,8,9-heptahydro-1-phenyl-5-(p-chlorophenylimino)-1H-benzo[e][1,4]thiazepine(HPT)(1.37%).The principal elemental components of Alstonia parvifolia were Ca(4.012%)and K(1.496%),as exhibited by energy dispersive X-ray examination.Alstonia parvifolia showed significant free radical scavenging ability(IC_(50):0.287 mg/mL)and was non-cytotoxic to normal HDFn cells(IC_(50)>100μg/mL).Moreover,Alstonia parvifolia was favorably cytotoxic to MCF-7(IC_(50):4.42µg/mL),followed by H69PR,HT-29,and THP-1,with IC_(50) values of 4.94,5.07,and 6.27µg/mL,respectively.Alstonia parvifolia also displayed notable inhibition against PLA_(2) activity of Naja philippinensis Taylor venom with IC_(50) of(15.2±1.8)μg/mL.Docking and cluster analyses projected negative binding energies from AFM(−6.36 to−9.68 kcal/mol),HPT(−7.38 to−9.77 kcal/mol),and acetylmarinobufogenin(−7.22 to−9.59 kcal/mol).These calculations were for the particular interactions of Alstonia parvifolia constituents to PLA_(2) homologues where the utmost affinity was detected in HPT owing to the dipole interactions with amino acid residues.Conclusions:The bark extract of Alstonia parvifolia shows great potential as an anti-venom agent due to its low cytotoxic profile,remarkable PLA_(2) inhibition,and docking binding energies between its bioactive constituents and PLA_(2) homologues.展开更多
文摘Aim： To determine the cellular distribution of secretory phospholipase A2 （sPLA2） in dependence on the acrosomal state and under the action of elastase released under inflammatory processes from leukocytes. Methods： Acrosome reaction of spermatozoa was triggered by calcimycin. Human leukocyte elastase was used to simulate inflammatory conditions. To visualize the distribution of sPLA2 and to determine the acrosomal state, immunofluorescence techniques and lectin binding combined with confocal laser scanning fluorescence microscopy and flow cytometry were used. Results： Although sPLA2 was detected at the acrosome and tail regions in intact spermatozoa, it disappeared from the head region after triggering the acrosome reaction. This release of sPLA2 was associated with enhanced binding of annexin V-fluoroscein isothiocyanate （FITC） to spermatozoa surfaces, intercalation of ethidium-homodimer I, and binding of FITC-labelled concanavalin A at the acrosomal region. Spermatozoa from healthy subjects treated with elastase were characterized by release of sPLA2, disturbance of acrosome structure, and loss of vitality. Conclusion： The ability of spermatozoa to release secretory phospholipase A2 is related to the acrosomal state. Premature destabi- lization of the acrosome and loss of sPLA2 can occur during silent inflammations in the male genital tract. The distribution pattern of sPLA2 in intact spermatozoa might be an additional parameter for evaluating sperm quality.
基金The work was funded by the National Natural Science Foundation of China，Specialized Research Fund for the Doctoral Program of Higher Education，Chinese Ministry of Education,the open grant of the State Key Laboratory of Bio-organic and Natural Products Chemistry,CAS,and open grant of Institute of Bioscience,Fudan University
文摘A novel series of eight SMS and sPLA2 dual inhibitors containing indole and a-amino cyanide fragments of different length and substitution position was synthesized and evaluated by three different in vitro assays. Biological evaluation showed that all compounds provided inhibitory effects against SMS （about 50% inhibition at 100 μmol/L） and sPLA2 （14-32 μmol/L）. All the compounds had the SMS activity better than the positive control compound D609 in SMS2 homogenate, with compounds 5b and fie ideal for liver homogenate and SMS2 high expression cell homogenate, respectively.
基金supported by the De La Salle University Science Foundation in coordination with the University Research Coordination Office(Project number:18FU2TAY16-3TAY17).
文摘Objective:To evaluate antioxidant,cytotoxic,and anti-venom capacity of crude bark extracts of Alstonia parvifolia Merr.Methods:Gas chromatography-mass spectrometry(GC-MS)and energy dispersive X-ray analyses were accomplished to characterize the chemical constituents of Alstonia parvifolia.Biochemical characterization was evaluated using an inhibitory phospholipase A_(2)(PLA_(2))assay,DPPH,and cytotoxicity assays.Using the constituents listed in the GC-MS analyses,molecular docking was conducted to inspect the binding energies between the chosen compounds and selected PLA_(2) isoforms.Results:GC-MS analyses showed that the Alstonia parvifolia crude extract consisted predominantly of acetylmarinobufogenin(14.89%),γ-sitosterol(10.44%),3-O-methyl-D-glucose(5.88%),3,5-dimethoxy-4-hydroxyphenylacetic acid(5.30%),(2α,5α)-17-methoxyaspidofractinin-3-one(AFM)(4.08%),and 2,3,5,6,7,8,9-heptahydro-1-phenyl-5-(p-chlorophenylimino)-1H-benzo[e][1,4]thiazepine(HPT)(1.37%).The principal elemental components of Alstonia parvifolia were Ca(4.012%)and K(1.496%),as exhibited by energy dispersive X-ray examination.Alstonia parvifolia showed significant free radical scavenging ability(IC_(50):0.287 mg/mL)and was non-cytotoxic to normal HDFn cells(IC_(50)>100μg/mL).Moreover,Alstonia parvifolia was favorably cytotoxic to MCF-7(IC_(50):4.42µg/mL),followed by H69PR,HT-29,and THP-1,with IC_(50) values of 4.94,5.07,and 6.27µg/mL,respectively.Alstonia parvifolia also displayed notable inhibition against PLA_(2) activity of Naja philippinensis Taylor venom with IC_(50) of(15.2±1.8)μg/mL.Docking and cluster analyses projected negative binding energies from AFM(−6.36 to−9.68 kcal/mol),HPT(−7.38 to−9.77 kcal/mol),and acetylmarinobufogenin(−7.22 to−9.59 kcal/mol).These calculations were for the particular interactions of Alstonia parvifolia constituents to PLA_(2) homologues where the utmost affinity was detected in HPT owing to the dipole interactions with amino acid residues.Conclusions:The bark extract of Alstonia parvifolia shows great potential as an anti-venom agent due to its low cytotoxic profile,remarkable PLA_(2) inhibition,and docking binding energies between its bioactive constituents and PLA_(2) homologues.
