Antioxidant, cytotoxic, and anti-venom activity of Alstonia parvifolia Merr. Bark

Maria Tan; Mary Carranza; Raymond Malabed; Yves Reyes; Francisco Franco; Virgilio Linis; Raymond Malabed; Glenn Oyong

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Antioxidant, cytotoxic, and anti-venom activity of Alstonia parvifolia Merr. Bark

Author: Maria TAN ¹ ; Mary CARRANZA ¹ ; Raymond MALABED ¹ ; Yves REYES ¹ ; Francisco FRANCO ¹ ; Virgilio LINIS ² ; Raymond MALABED ³ ; Glenn OYONG ⁴
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1. Chemistry Department, De la Salle University
2. Biology Department, De la Salle University
3. Department of Chemistry, Graduate School of Science, Osaka University
4. Molecular Science Unit Laboratory, Center for Natural Sciences and Environmental Research, De la Salle University
Publication Type:Journal Article
Keywords: Alstonia parvifolia Merr.; Anti-venom; Cytotoxicity assay; Gas chromatography-electron ionization-mass spectrometry; Naja philippinensis Taylor; Secretory phospholipase A2
From:Asian Pacific Journal of Tropical Biomedicine 2021;11(10):460-468
CountryChina
Language:Chinese
Abstract: 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 >100 μg/mL). Moreover, Alstonia parvifolia was favorably cytotoxic to MCF-7 (IC 50: 4.42 μg/mL), followed by H69PR, HT-29, and THP-1, with IC 50 values of 4.94, 5.07, and 6.27 μg/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.