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Background: Asystasia gangetica, also referred to as Chinese Violet is an invasive weed that has been revealed to contain biologically active components and manifest pharmacological effects. Phytochemical analysis on different extracts of A. gangetica reported that the plant contains steroids, sugars, phenolics, flavonoids, saponins, tannins and amino acids, alkaloids, terpenoids, quinines and carbohydrates and bioassay techniques performed using the plant material manifested its antioxidant, anti-asthmatic and antidiabetic properties. Materials and Methods: To further understand how the existing and the potential abilities of A. gangetica possibly work, the total phenolics, total flavonoids, total condensed tannins and total polysaccharide content of different extracts of A. gangetica have been analyzed as well as its antioxidation properties using DDPH and FRAP assays. The effect of combining A. gangetica extract to the methanolic extract of Morus alba leaves on the potency of the antioxidation properties of both plant materials was also explored. Results: Evaluation of the results revealed that A. gangetica ethanol extract is the extract most abundant in polyphenol, DCM extract in flavonoids and condensed tannins, while only a few extracts had polysaccharides. Ethanol extract has the most promising DPPH free radical scavenging activity, while methanol extract was reported to have the highest Trolox equivalent. No significant synergistic effect was observed in the combination of A. gangetica and M. alba extracts. Conclusion: These findings provide information on the A. gangetica extracts as antioxidant agents and as a source of natural products. Consequently, the results provide a new direction for medical research. [ABSTRACT FROM AUTHOR]

Background: This study aimed to isolate the bioactive components from the aerial parts of Premna odorata Blanco and to evaluate the hypoglycemic potentials of the crude extracts, sub-fractions and final isolate. Materials and Methods: The plant material underwent a series of enzyme assay-guided isolation and purification having the fractions assayed for inhibitory activity against a-amylase using 3,5-dinitrosalicylic acid (DNS) colorimetric method for each stage. H.1 isolate was tested for a-amylase and a-glucosidase inhibitory activity and glucose uptake by yeast cells. Phytochemical characterization and 1H and 13C NMR spectral analysis were done for the structure elucidation of H.1. Results: In vitro amylase studies revealed that at 100 µg/mL concentrations, hexane crude extract, fraction F (20%/80% and 10%/90% n-hexane/dichloromethane fractions) and F.3 (10:1 v/v petroleum ether/ethyl acetate sub-fraction) exhibited 34.38±0.116%, 71.86± 4.909% and 42.16±1.257% inhibition against a-amylase (at 1000 µg/mL concentration), respectively. H.1 isolate exerted significant inhibition (p < 0.05) of 55.99± 2.202% and 72.43±3.988% against a-amylase and a-glucosidase enzyme (both at 1000 µg/mL concentration), respectively and significant glucose uptake of 13.85± 0.368%. The purified isolate was spectroscopically confirmed as a 5:1 mixture of ß-sitosterol (H.1a) and stigmasterol (H.1b). Conclusion: The compounds have significant inhibitory activity against carbohydrate-hydrolyzing enzymes and may be potentially developed as adjuvant pharmacotherapy for type 2 diabetes. [ABSTRACT FROM AUTHOR]