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
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.
