Table 1.

IC₅₀ values of the methanol extracts of the four plants investigated on untreated SH-SY5Y cells.

Plant and part	Neutral red assay IC50 (µg/ml)	MTT assay IC50 (µg/ml)
Z. mucronata roots	>100	>100
L. schweinfurthii roots	>100	>100
T. sericea roots	>100	95.14 ± 2.45
C. bulbispermum roots	10.71 ± 0.26	12.53 ± 0.89
C. bulbispermum bulbs	47.26 ± 0.68	48.84 ± 4.62