Table 5.

Antityrosinase activity and IC₅₀ (mg/mL) of various M. speciosa stem extracts.

Compound	Concen. (mg/mL)	Petroleum ether		Ethyl acetate		Methanol
		Inhibition (%) ± SD	IC50 (mg/mL)	Inhibition (%) ± SD	IC50 (mg/mL)	Inhibition (%) ± SD	IC50 (mg/mL)
Extract	0.5	31.22 ± 0.70	4.58	29.54 ± 0.73	6.10	13.72 ± 0.70	8.91
	2.0	36.29 ± 0.63		33.52 ± 0.65		19.49 ± 0.68
	3.5	44.53 ± 0.62		38.79 ± 0.66		26.27 ± 0.63
	5.0	51.67 ± 0.64		45.39 ± 0.55		32.57 ± 0.90
	6.5	59.99 ± 0.72		52.61 ± 0.83		39.92 ± 0.72
	8.0	70.97 ± 0.66		59.84 ± 0.67		46.67 ± 0.67
Positive control	Concen. (mg/mL)						IC50 (mg/mL)
Arbutin	0.5	2.0	3.5	5.0	6.5	8.0	3.49
	Inhibition (%) ± SD
	27.23 ± 0.29	38.19 ± 0.72	50.89 ± 0.56	62.16 ± 0.81	71.65 ± 0.66	82.65 ± 0.66
Vitamin C	Concen. (mg/mL)						2.73
	0.5	2.0	3.5	5.0	6.5	8.0
	Inhibition (%) ± SD
	32.75 ± 0.59	44.35 ± 0.56	56.12 ± 0.52	67.69 ± 0.53	78.73 ± 0.59	92.89 ± 1.17