Fig. 4
Protective effects of the crude ethanolic extract of S. asper leaves and its fractions against glutamate-induced neuronal cell death. a Relative MTT viability of HT22 cells exposed to various concentrations of extracts. ###P = 8.8 × 10− 5 for 25 μg/mL and ###P = 7.5 × 10− 6 for 50 μg/mL of basic fraction vs. control. b Relative MTT viability of HT22 cells exposed to glutamate alone or glutamate combined with different concentrations of extracts. ###P = 2.9 × 10− 11 vs. control; *P = 3.1 × 10− 2 and ***P = 2.9 × 10− 11 vs. glutamate-treated cells. c Representative morphological images at 5X magnification (scale bar = 100 μm) of untreated HT22 cells (control), or cells treated with glutamate alone, or with glutamate plus crude extract or fractions at 1 and 10 μg/mL. Data are expressed as means ± SEM of 4 independent experiments with 2–3 replicates each