Bioguided Fractionation and Purification of Natural Bioactives Obtained from<i>Alpinia conchigera</i> Water Extract with Melanin Inhibition Activity

Abstract

Crude extracts of Alpinia conchigera a species from the Malaysian Ginger (Zingiberaceae) family and its fractions obtained from various extraction methods were assayed for melanogenesis inhibition activity and cell viability. The crude extract obtained from the ethanolic extraction and the super critical fluid extraction did not exhibit significant melanin inhibition activity and was shown to be toxic to the melanocyte cells in comparison to the water extract. The crude aqueous extracts displayed melanin inhibition of 96.38 ± 1.60% and cell viability 109.90 ± 8.32% at a concentration of 500 µg/mL. Bioassay guided fractionation was performed on the water extracts to isolate the active compounds. The actives were identified as trans-cinnamaldehyde and chavicol glucopyranoside with both compound showing potent anti-melanogenesis activity. At 4.9 µg/ml, both trans-cinnamaldehyde and chavicol glucopyranoside gave 85% inhibition of melanin formation in vitro with 77% and 97% cell viability respectively. In comparison, kojic acid, a known skin lightening agent showed 90.0% inhibition at 100 µg/mL. The bioactive composition comprising the extract, active fraction, purified compounds or mixture thereof of Alpinia conchigera may be used for cosmetic and pharmaceutical applications, particularly for the purposes of reducing skin pigmentation.

Preparation of medicinal plants: Basic extraction and fractionation procedures for experimental purposes

“…The container is then closed and kept for at least three days. [ 1 2 3 4 11 16 ] The content is stirred periodically, and if placed inside bottle it should be shaken time to time to ensure complete extraction. At the end of extraction, the micelle is separated from marc by filtration or decantation.…”

“…Subsequently, the micelle is then separated from the menstruum by evaporation in an oven or on top of water bath. [ 1 2 3 4 11 16 ] This method is convenient and very suitable for thermolabile plant material. Infusion .…”

“…Separation is initiated via interaction of the compounds in the mixture with the solid particle of the stationary phase. [ 1 4 5 16 23 ] The apparatus consists of a solvent reservoir, sample injector, pressure pump, HPLC tube, and diode detector. The process begins by injecting the mixture to be separated at the bottom of HPLC.…”

“…Finally, the mixture moved into the diode detector, which separated the compounds, removed the waste, and pumped the final content to processing units. [ 1 4 5 16 23 ]…”

Anti-quorum sensing and anti-biofilm activity of Amomum tsaoko (Amommum tsao-ko Crevost et Lemarie) on foodborne pathogens

“…The percentage of extraction yields will increase or decrease with the ratio of solvent, temperature of extraction and extraction methods (green extractions, microwave assisted solvent extraction, ultrasound, etc.). Crude extracts of Alpinia conchigera a species from the Malaysian Ginger (Zingiberaceae) family showed 10.76% extractions yield when the ratio of powdered rhizomes and ethanol was 1:10 (w/v) (Ujang et al, 2013). This is consistent with our result.…”