OBJECTIVE: This study investigates the antidiabetic and antioxidant effects of M. latifolia bark extracts, fractions, and isolated constituents.
MATERIALS AND METHODS: Melicope latifolia extracts (hexane, chloroform, and methanol), fractions, and isolated constituents with varying concentrations (0.078-10 mg/mL) were subjected to in vitro α-amylase and dipeptidyl peptidase-4 (DPP-4) inhibitory assay. Molecular docking was performed to study the binding mechanism of active compounds towards α-amylase and DPP-4 enzymes. The antioxidant activity of M. latifolia fractions and compounds were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and β-carotene bleaching assays.
RESULTS: Melicope latifolia chloroform extract showed the highest antidiabetic activity (α-amylase IC50: 1464.32 μg/mL; DPP-4 IC50: 221.58 μg/mL). Fractionation of chloroform extract yielded four major fractions (CF1-CF4) whereby CF3 showed the highest antidiabetic activity (α-amylase IC50: 397.68 μg/mL; DPP-4 IC50: 37.16 μg/mL) and resulted in β-sitosterol (1), halfordin (2), methyl p-coumarate (3), and protocatechuic acid (4). Isolation of compounds 2-4 from the species and their DPP-4 inhibitory were reported for the first time. Compound 2 showed the highest α-amylase (IC50: 197.53 μM) and β-carotene (88.48%) inhibition, and formed the highest number of molecular interactions with critical amino acid residues of α-amylase. The highest DPP-4 inhibition was exhibited by compound 3 (IC50: 911.44 μM).
DISCUSSION AND CONCLUSIONS: The in vitro and in silico analyses indicated the potential of M. latifolia as an alternative source of α-amylase and DPP-4 inhibitors. Further pharmacological studies on the compounds are recommended.
METHOD: Twenty-four male Wistar rats were divided into four groups which consist of normal, 1.8 g/kg ethanol (40% v/v), 200 mg/kg Z. zerumbet extract plus ethanol and 400 mg/kg Z. zerumbet plus ethanol. The extract of Z. zerumbet was given once daily by oral gavage, 30 min prior to ethanol exposure via intraperitoneal route for 14 consecutive days. The rats were then sacrificed. Blood and brain homogenate were subjected to biochemical tests and part of the brain tissue was sectioned for histological analysis.
RESULT: Treatment with ethyl-acetate Z. zerumbet extract at 200 mg/kg and 400 mg/kg significantly reduced the level of malondialdehyde (MDA) and protein carbonyl (p
METHOD: Dichloromethane, methanol, and water extracts of the leaves and roots of M. pumilum var. alata, M. pumilum var. pumila, and M. pumilum var. lanceolata were tested using an in vitro xanthine oxidase inhibitory assay. Bioassay-guided fractionation and isolation were carried out on the most active extract using chromatographic techniques. The structures of the isolated compounds were determined using spectroscopic techniques.
RESULTS: The most active dichloromethane extract of M. pumilum var. pumila leaves (IC50 = 161.6 μg/mL) yielded one new compound, 3,7-dihydroxy-5-methoxy-4,8-dimethyl-isocoumarin (1), and five known compounds, viz. ardisiaquinone A (2), maesanin (3), stigmasterol (4), tetracosane (5), and margaric acid (6). The new compound was found to be the most active xanthine oxidase inhibitor with an IC50 value of 0.66 ± 0.01 μg/mL, which was not significantly different (p > 0.05) from that of the positive control, allopurinol (IC50 = 0.24 ± 0.00 μg/mL).
CONCLUSION: This study suggests that the new compound 3,7-dihydroxy-5-methoxy-4,8-dimethyl-isocoumarin (1), which was isolated from the dichloromethane extract of M. pumilum var. pumila leaves, could be a potential xanthine oxidase inhibitor.
AIM OF THE STUDY: To investigate the effects of E. guineensis leaf on wound healing activity in rats.
METHODS: A phytochemical screening was done to determine the major phytochemicals in the extract. The antimicrobial activity of the extract was examined using the disk diffusion technique and broth dilution method. The wound healing activity of leaves of E. guineensiswas studied by incorporating the methanolic extract in yellow soft paraffin in concentration of 10% (w/w). Wound healing activity was studied by determining the percentage of wound closure, microbial examination of granulated skin tissue and histological analysis in the control and extract treated groups.
RESULTS: Phytochemical screening reveals the presence of tannins, alkaloids, steroids, saponins, terpenoids, and flavonoids in the extract. The extract showed significant activity against Candida albicans with an MIC value of 6.25 mg/mL. The results show that the E. guineensis extract has potent wound healing capacity, as evident from better wound closure, improved tissue regeneration at the wound site, and supporting histopathological parameters pertaining to wound healing. Assessment of granulation tissue every fourth day showed a significant reduction in microbial count.
CONCLUSIONS: E. guineensis accelerated wound healing in rats, thus supporting this traditional use.
METHODS: The cytoprotective role of AEIA was measured on mouse hepatocytes by cell viability assay followed by Hoechst staining and flow cytometric assay. The effect on ROS production, lipid peroxidation, protein carbonylation, intracellular redox status were measured after incubating the hepatocytes with Pb-acetate (6.8 μM) along with AEIA (400 μg/ml). The effects on the expressions of apoptotic signal proteins were estimated by western blotting. The protective role of AEIA was measured by in vivo assay in mice. Haematological, serum biochemical, tissue redox status, Pb bioaccumulation and histological parameters were evaluated to estimate the protective role of AEIA (100 mg/kg) against Pb-acetate (5 mg/kg) intoxication.
RESULTS: Pb-acetate treated hepatocytes showed a gradual reduction of cell viability dose-dependently with an IC50 value of 6.8 μM. Pb-acetate treated hepatocytes exhibited significantly enhanced levels (p < 0.01) of ROS production, lipid peroxidation, protein carbonylation with concomitant depletion (p < 0.01) of antioxidant enzymes and GSH. However, AEIA treatment could significantly restore the aforementioned parameters in murine hepatocytes near to normalcy. Besides, AEIA significantly reversed (p < 0.05-0.01) the alterations of transcription levels of apoptotic proteins viz. Bcl 2, Bad, Cyt C, Apaf-1, cleaved caspases [caspase 3, caspase 8 and caspase 9], Fas and Bid. In in vivo bioassay, Pb-acetate treatment caused significantly high intracellular Pb burden and oxidative pressure in the kidney, liver, heart, brain and testes in mice. In addition, the haematological and serum biochemical factors were changed significantly in Pb-acetate-treated animals. AEIA treatment restored significantly the evaluated-parameters to the near-normal position.
CONCLUSION: The extract may offer the protective effect via counteracting with Pb mediated oxidative stress and/or promoting the elimination of Pb by chelating. The presence of substantial quantities of flavonoids, phenolics and saponins would be responsible for the overall protective effect.
AIM OF THE STUDY: This study is designed to investigate the vasorelaxant effect of Chen pi and to study its pharmacology effects.
MATERIALS AND METHODS: The vasorelaxant effect of water extract of Chen pi (CRW) were evaluated on thoracic aortic rings isolated from Sprague Dawley rats. The fingerprint of Chen pi and the extracts were developed with quantification of hesperidin content by HPTLC.
RESULTS: CRW exhibited the strongest vasorelaxant activity. CRW caused the relaxation of the phenylephrine pre-contracted aortic rings in the presence and absence of endothelium as well as in potassium chloride pre-contracted endothelium-intact aortic ring. The incubation of propranolol (β-adrenergic receptor blocker), atropine (muscarinic receptor blocker), Nω-nitro-L-arginine methyl ester (NO synthase inhibitor), ODQ (sGC inhibitor), indomethacin (COX inhibitor), 4-aminopyridine (KV blocker), barium chloride (Kir blocker), and glibenclamide (KATP blocker) significantly reduced the vasorelaxant effects of CRW. CRW was also found to be active in reducing Ca2+ releases from the sarcoplasmic reticulum and suppressing the voltage-operated calcium channels.
CONCLUSION: The vasorelaxant effect of CRW on rat aorta involves NO/sGC, calcium and potassium channels, muscarinic and β-adrenergic receptors.
METHODS: The aqueous ethanolic leaf extracts of C. caudatus were characterized by NMR and LC-MS/MS. The total phenolic content and α-glucosidase inhibitory activity were evaluated by the Folin-Ciocalteu method and α-glucosidase inhibitory assay, respectively. The statistical significance of the results was evaluated using one-way ANOVA with Duncan's post hoc test, and correlation among the different activities was performed by Pearson's correlation test. NMR spectroscopy along with multivariate data analysis was used to identify the metabolites correlated with total phenolic content and α-glucosidase inhibitory activity of the C. caudatus leaf extracts.
RESULTS: It was found that the α-glucosidase inhibitory activity and total phenolic content of the optimized ethanol:water (80:20) leaf extract of the plant increased significantly as the plant matured, reaching a maximum at the 10th week. The IC50 value for α-glucosidase inhibitory activity (39.18 μg mL- 1) at the 10th week showed greater potency than the positive standard, quercetin (110.50 μg mL- 1). Through an 1H NMR-based metabolomics approach, the 10-week-old samples were shown to be correlated with a high total phenolic content and α-glucosidase inhibitory activity. From the partial least squares biplot, rutin and flavonoid glycosides, consisting of quercetin 3-O-arabinofuranoside, quercetin 3-O-rhamnoside, quercetin 3-O-glucoside, and quercetin 3-O-xyloside, were identified as the major bioactive metabolites. The metabolites were identified by NMR spectroscopy (J-resolve, HSQC and HMBC experiments) and further supported by dereplication via LC-MS/MS.
CONCLUSION: For high phytomedicinal quality, the 10th week is recommended as the best time to harvest C. caudatus leaves with respect to its glucose lowering potential.