Effects of different drying methods on the antioxidant properties of leaves and tea of ginger species
... Abstract. Effects of five different drying methods on the antioxidant properties (AOP) of lea... more ... Abstract. Effects of five different drying methods on the antioxidant properties (AOP) of leaves of Alpinia zerumbet, Etlingera elatior, Curcuma longa, and Kaempferia galanga were assessed. ...Etlingera elatior or Torch Ginger is widely cultivated throughout the tropics. ...
Background: Our earlier study on the antiproliferative (APF) activity of leaf extracts of ten Apo... more Background: Our earlier study on the antiproliferative (APF) activity of leaf extracts of ten Apocynaceae species showed that leaves of Vallaris glabra possessed strong and broad‑spectrum properties. Materials and Methods: In this study, sequential extracts of leaves, flowers and stems, and fractions and isolated compounds from dichloromethane (DCM) leaf extract of V. glabra were assessed for APF activity using the sulphorhodamine B (SRB) assay. Apoptotic effect of MDA‑MB‑231 cancer cells treated with DCM leaf extract of V. glabra was studied using Hoechst 33342 dye and caspase colorimetry. Results: Both DCM extracts of leaves and flowers possessed broad‑spectrum APF activity against HT‑29, MCF‑7, MDA‑MB‑231 and SKOV‑3 cancer cells. From DCM leaf extract, stearic acid (SA) and ursolic acid (UA) were isolated by column chromatography, and identified by NMR and MS analyses. APF activity of SA from DCM leaf extract displayed weak inhibitory activity and scientific literature showed UA has anticancer properties against those cancer cells used in this study. MDA‑MB‑231 cancer cells treated with DCM leaf extract and stained with Hoechst 33342 dye provided evidence that the extract had an apoptotic effect on the cells. Caspase colorimetry showed that the apoptotic effect involved activation of caspase‑8, ‑9 and ‑3, but not caspase‑6. Conclusion: The potential of V. glabra as a candidate species for anticancer drugs warrants further investigation.
Lagerstroemia speciosa (Lythraceae) has several common names, which reflect its attractive and co... more Lagerstroemia speciosa (Lythraceae) has several common names, which reflect its attractive and colourful pink or purple flowers. Native to South and Southeast Asia, L. speciosa is a common ornamental tree planted along roadsides, and in gardens and parks. The species has been traditionally used in folk medicine as remedy for illnesses and ailments, particularly for lowering blood sugar level, reducing body weight, and as a remedy for diabetes. The current knowledge on the phytochemistry and pharmacology of L. speciosa is reviewed since the species has been regarded as a natural product for anti-diabetic drugs. Triterpenes, tannins, ellagic acids, glycosides and flavones have been isolated from the leaves. Pharmacological properties of the species include antioxidant, antibacterial, antiviral, anti-inflammatory, antinociceptive, antidiarrhoeal, cytotoxic, xanthine oxidase inhibition, anti-obesity and anti-fibrotic activities. A more exhaustive review is accorded to its anti-diabetic properties, which have generated much research involving in vitro, animal and human studies.
Uploads
Papers by Siu Kuin Wong
properties. Materials and Methods: In this study, sequential extracts of leaves, flowers and stems, and fractions and isolated compounds from dichloromethane (DCM) leaf extract of V. glabra were assessed for APF activity using the sulphorhodamine B (SRB) assay. Apoptotic effect of MDA‑MB‑231 cancer cells treated with DCM leaf extract of V. glabra was studied using Hoechst 33342 dye and caspase colorimetry. Results: Both DCM extracts of leaves and flowers
possessed broad‑spectrum APF activity against HT‑29, MCF‑7, MDA‑MB‑231 and SKOV‑3 cancer cells. From DCM leaf extract, stearic acid (SA) and ursolic acid (UA) were isolated by column chromatography, and identified by NMR and MS analyses. APF activity of SA from DCM leaf extract displayed weak inhibitory activity and scientific literature showed UA has anticancer properties against those cancer cells used in this study. MDA‑MB‑231 cancer cells treated with DCM leaf extract and stained with Hoechst 33342 dye provided evidence that the extract had an apoptotic effect on the cells. Caspase colorimetry showed that the apoptotic effect involved
activation of caspase‑8, ‑9 and ‑3, but not caspase‑6. Conclusion: The potential of V. glabra as a candidate species for anticancer drugs warrants further investigation.