Antiapoptotic and Antioxidant Properties of Orthosiphon stamineus Benth (Cat's Whiskers)‎ : Intervention in the Bcl-2-Mediated Apoptotic Pathway

Abstract EN

Antiapoptotic and antioxidant activities of aqueous-methanolic extract (CAME) of Orthosiphonstamineus Benth(OS), and its hexane (HF), chloroform (CF), n-butanol (NBF), ethyl acetate (EAF) and water (WF) fractions were investigated.

Antioxidant properties were evaluated using the assays of Folin-Ciocalteu, aluminiumtrichloride, β-carotene bleaching and DPPH.

The role of OS against hydrogen peroxide induced apoptosis on MDA-M231 epithelial cells was examined using MTT assay, phase contrast microscope, colorimetric assay of caspase-3, western blot and quantitative real-time PCR.

Results showed that EAF showed the highest total phenolic content followed by CAME, NBF, WF, CF and HF, respectively.

Flavonoid content was in the order of the CF > EAF > HF > CAME > NBF > WF.

The IC50 values on DPPH assay for different extract/fractions were 126.2 ± 23, 31.25 ± 1.2, 15.25 ± 2.3, 13.56 ± 1.9, 23.0 ± 3.2, and 16.66 ± 1.5 μg/ml for HF, CF, EAF, NBF, WF and CAME, respectively.

OSreduced the oxidation of β-carotene by hydroperoxides.

Cell death was dose-dependently inhibited by pretreatment with OS.

Caspase-3 and distinct morphological features suggest the anti-apoptotic activities of OS.

This plant not only increased the expression of Bcl-2, but also decreased Bax expression, and ultimately reduced H2O2-induced apoptosis.

The current results showed that phenolics may provide health and nutritional benefits.