Fig. 6.

Luteolin treatment improves motor function and promotes neurological functional recovery in ischemic stroke mice. (a) Experimental diagram showing the procedure for examining the effect of luteolin administration in vivo with a series of behavioral tests after the mice underwent ischemic stroke surgeries. (b and c) Representative images of magnetic resonance imaging (MRI) (b) and summary graph (c) of the infarct volumes after occlusions in tMCAO mice after luteolin and its control (saline) administration at days 1, 3, 6 and 9, respectively. Note that after day 6, intraperitoneal injection of luteolin significantly decreases the infarction volumes in tMCAO mice. ∗∗∗p < 0.001, n.s indicates not significant, two-tailed unpaired t-test. n represents the number of mice examined per group. (d) Schematic cartoon illustrates the severity of tMCAO mouse regarding corner test performance. As expected, the mouse of sham control does not have a preference to turn. After the mouse receives tMCAO, the animal prefers to turn left as evidenced by a significant increase of laterality index. (e) Summary graph shows a trend for improvement of the severity in tMCAO mice with luteolin treatment starting at day 6 compared with the saline group. ∗∗∗p < 0.001, n.s indicates not significant, two-tailed unpaired t-test. n represents the number of mice examined per group. (f) Schematic cartoon illustrates the motor ability of tMCAO mouse in the grid-walking performance test. (g) Summary graph shows tMCAO mice under luteolin treatment after day 6 demonstrating a better placement of their impaired left forelimbs/hindlimbs by decreasing their footfalls when they freely walked on the grid squares compared with the saline group. ∗∗∗p < 0.001, two-tailed unpaired t-test, n.s indicates not significant, n = 6 and 7 mice for saline and luteolin group, respectively. (h) Schematic cartoon illustrates sensorimotor function of tMCAO mouse during rotarod test performance. (i) Summary graph shows tMCAO mice under luteolin treatment after day 6 demonstrating a prolonged latency to fall when they were placed on an accelerating rotating rod. ∗p < 0.05, two-tailed unpaired t-test, n.s indicates not significant, n = 6 and 7 mice for saline and luteolin group, respectively. (j) Summary graph showing the modified neurological severity score (mNSS) to assess the mice motor, sensory, balance and reflex behaviors. 1 score point reflects the inability to perform the test and 16 score point indicates the worst severity of the injury. The tMCAO mice after 6 days administration of luteolin overall show a better neurological improvement compared with the saline group. ∗∗p < 0.01, two-tailed unpaired t-test, n.s indicates not significant, n = 6 and 7 mice for saline and luteolin group, respectively. (k) Summary graph of survival curve shows a 73% survival rate of tMCAO mice under a 9-day-period of luteolin treatment compared with a 53% survival rate of tMCAO mice in saline group. n = 15 mice for per group.