The effect of extraction temperature and extractions time on antioxidant activity in orthosiphon stamineus

A plants namely Orthosiphon stamineus was collected from Kelantan, Malaysia were screened for their in vitro antioxidants. Stems and leaves of selected plants were dried at room temperature 24˚C and blended to powder form for further extraction. Then, extraction was performed in water-bath machine with the solvent 100% methanol. By employing DPPH (2,2 diphenyl-1- radical) scavenging assays, it was show that all the methanol extracts of the samples collected were endowed with antioxidant activity with a range of colour change for the sample, as expected, their potency varied according to the different part and species. In particular, stem of Orthosiphon Stamineus displayed slightly more activity than leaves part. The IC50 value of the extracts tested were ranged from 0.122 μg/ml - 1.953 μg/ml. It is generally accepted that a diet rich in plants associated with a reduced incidence of degenerative diseases, such as atherosclerosis and cancer. This study suggests that the antioxidants properties in Orthosiphon stamineus plants could be significantly effect by extraction in high temperature and extraction time.