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

Table 2

Effects of extract/fractions of O. stamineus on cell viability.

Treatment*	Concentrations of extract/fractions of O. stamineus
	500 μg/mL	250 μg/mL	125 μg/mL	62.5 μg/mL
HF + Hydrogen Peroxide	25.90±0.95 *	22.37±1.56 *	20.61±0.94 *	23.10±3.18 *
CF + Hydrogen Peroxide	70.81±10.24 **	43.03±2.65 **	24.81±0.09 **	20.66±1.56 *
EAF + Hydrogen Peroxide	100.00±27.75 **	100.00±16.51 **	84.82±3.98 **	56.43±5.98 **
NBF + Hydrogen Peroxide	100.00±8.69 **	66.03±0.01 **	37.92±0.99 **	29.90±4.00 **
WF + Hydrogen Peroxide	65.62±10.70 **	35.20±13.12 *	23.88±1.51 *	23.41±5.49 *
CAME + Hydrogen Peroxide	91.31±5.32 **	52.64±7.56 **	37.53±1.65 *	26.27±1.86 *
Quercetin + Hydrogen Peroxide	95.45±3.72 **
Hydrogen Peroxide control	15.86±0.23
Control cells	100**

*Cell viability after 2 h exposure in 400 μmol/L H₂O₂ was assayed by MTT. Cells were preincubated with different tested samples (62.5, 125, 250, and 500 μg/mL) for 10 min before the addition of 400 μmol/L H₂O₂. After 2 h incubation, MTT was added to a final concentration of 0.5 mg/mL and then incubated at 37°C for another 2 hrs; the resultant formazan product was extracted for 4 h with DMSO and detected by UV-spectrometer at 570 nm. Values are expressed as means ± SD (𝑁=3). *𝑃<.05, **𝑃<.01 versus hydrogen peroxide control.