Anticonvulsant activity of aqueous fraction of Carissa edulis root bark

Figures & data

Figure 1. Scheme depicting different fractions of ethanolic root bark extract of Carissa edulis (CEE), EAF, NBF, PEF, and RAF.

Table 1. Phytochemical constituents RAF.

Constituents	RAF
Alkaloids	−
Anthraquinones	+
Tannins	+
Steroids/triterpenes	+
Cardiac glycosides	−
Saponins	+
Flavonoids	+

Key: +, present; −, absent; RAF, residual aqueous fraction.

Table 2. Effects RAF on pentylenetetrazole (PTZ)-induced seizures in mice.

Treatment (mg/kg)	Mean onset of seizure (min)	% Seizure protection	Mean onset of mortality (min)	% Mortality protection
Control	4.67 ± 0.42	0.0	17.0 ± 3.18	16.7
RAF 150	5.40 ± 1.44	33.3	13.75 ± 1.89	33.3
RAF 300	12.40 ± 4.08	16.7	15.20 ± 2.67	16.7
RAF 600	12.67 ± 0.67***	50.0	19.33 ± 4.33	50.0
VAL 200	0.00	100.00	0.00	100.00
DZP 1	0.00	100.00	0.00	100.00

Control, distilled water, RAF, residual aqueous fraction; VAL, sodium valproate was administered 30 min intraperitoneally before the injection of PTZ (85 mg/kg) subcutaneously. Values are the mean ± SEM, n = 6, ***p < 0.001 Dunnett’s post hoc multiple comparison test after one-way ANOVA.

Table 3. Effects of RAF on picrotoxin-induced seizures in mice.

Treatment (mg/kg)	Onset of seizure (min)	% Seizure protection	% Mortality protection
Control	6.17 ± 0.65	0.0	0.0
RAF 150	9.00 ± 0.73*	0.0	0.0
RAF 300	8.67 ± 0.56*	0.0	0.0
RAF 600	8.17 ± 0.98	0.0	0.0
PHB 30	10.6 ± 1.21*	16.7	16.7

Control, distilled water; RAF, residual aqueous fraction; PHB, phenobarbital was administered 30 min intraperitoneally before the injection of picrotoxin (10 mg/kg) subcutaneously. Values are the mean ± SEM, n = 6, one-way ANOVA df: 28, F: 3.55, α < 0.05; *p < 0.05 Dunnett’s post hoc multiple comparison.

Table 4. Effects of RAF on strychnine-induced seizures in mice.

Treatment (mg/kg)	Onset of seizure/ mortality (min)	% Seizure/mortality protection
Control	6.67 ± 0.71	0.0
RAF 150	6.83 ± 0.70	16.7
RAF 300	7.17 ± 0.70	0.0
RAF 600	8.25 ± 1.03	33.3
PHB 30	0.0	100

Control, distilled water; RAF, residual aqueous fraction; PHB, phenobarbital was administered 30 min intraperitoneally before the injection of strychnine (2.5 mg/kg) subcutaneously. Values are the mean ± SEM, n = 6.

Figure 2. Effects of residual aqueous fraction (RAF) of ethanolic extract of Carissa edulis root bark on maximal electroshock test (MEST)-induced seizures in chicks, n = 10.

Table 5. Effects of RAF on N-methyl-d-aspartate (NMDA)-induced seizures in mice.

Treatment (mg/kg)	Quantal protection	Mean seizure onset (min)	Mortality rate	Mean mortality time (min)
Control	0/6	9.25 ± 1.97	6/6	13.25 ± 3.77
RAF 150	0/6	13.20 ± 2.94	6/6	13.20 ± 2.94
RAF 300	1/6	10.00 ± 1.70	3/6	9.00 ± 1.53
RAF 600	1/6	11.80 ± 1.93	6/6	12.80 ± 2.42
PHB 30	0/6	8.17 ± 0.54	3/6	13.25 ± 3.77

Control, distilled water; RAF, residual aqueous fraction; PHB, phenobarbital was administered 30 min intraperitoneally before the injection of NMDA (320 mg/kg) subcutaneously. Values are the mean ± SEM, n = 6.

Table 6. Effect of RAF on aminophylline-induced seizures in mice.

Treatment (mg/kg)	Mean onset of myoclonic seizure (min)	Quantal protection	Mean onset of THLE/mortality
Control	31.33 ± 0.88	0/6	39.00 ± 2.08
RAF 150	40.17 ± 4.14	4/6	39.50 ± 6.50
RAF 300	51.33 ± 6.42*	3/6	44.67 ± 7.75
RAF 600	36.00 ± 2.65	2/6	35.00 ± 4.72
PHB 30	51.00 ± 0.00	6/6	–
ONE WAY  ANOVA	F = 3.100, α < 0.05		Not significant

Data presented as mean ± SEM, n = 6. Control, distilled water; RAF, residual aqueous fraction; PHB, phenobarbital; *p < 0.05 Dunnett’s post hoc test of multiple comparisons.

Table 7. Effect of residual aqueous fraction (RAF) of ethanolic extract of Carissa edulis root bark on isoniazid (INH)-induced seizures in mice.

Treatment (mg/kg)	Mean onset of myoclonic seizure (min)	Quantal protection	Mean onset of THLE/mortality
Control	23.17 ± 0.79	0/6	27.67 ± 0.99
RAF 150	27.16 ± 3.15	0/6	35.83 ± 3.82
RAF 300	27.67 ± 1.91	0/6	32.17 ± 3.03
RAF 600	31.67 ± 3.51	0/6	41.33 ± 3.54*
PYR 200	25.17 ± 1.78	0/6	33.67 ± 2.76
PHB 30	36.67 ± 1.90**	0/6	48.33 ± 4.30***
ONE WAY  ANOVA	F = 4.178, α < 0.005		F = 5.083, α < 0.05

Data presented as mean ± SEM, n = 6. Control, distilled water; RAF, residual aqueous fraction; PYR, pyridoxine; PHB, phenobarbital; *p < 0.05, **p < 0.005, and ***p < 0.001 Dunnett’s post hoc test of multiple comparisons.

Table 8. Effects of sub-fraction S1 of RAF on pentylenetetrazole (PTZ)-induced seizures in mice.

Treatment (mg/kg)	Mean onset of seizure (min)	% Seizure protection	Mean onset of mortality (min)	% Mortality protection
Control	4.50 ± 0.76	0.00	6.83 ± 0.91	0.0
S1 250	10.67 ± 2.06***	0.00	13.17 ± 2.20*	0.0
S1 500	14.60 ± 0.75 ***	16.67	14.33 ± 1.20*	33.3
S1 1000	11.40 ± 1.12***	16.67	11.40 ± 1.12	16.7
VA 200	0.0	100.0	0.0	100

Control, distilled water, S1 sub-fraction; VA, sodium valproate was administered 30 min intraperitoneally before the injection of PTZ (85 mg/kg) subcutaneously. Values are the mean ± SEM, n = 6. One-way ANOVA df: 21, F: 9.92, α < 0.001 (seizure onset), α < 0.05 (mortality onset), ***p < 0.001 and *p < 0.05 Dunnett post hoc test.

Table 9. Effects of sub-fraction S2 RAF on pentylenetetrazole (PTZ)-induced seizures in mice.

Treatment (mg/kg)	Mean onset of seizure (min)	% Seizure protection	Mean onset of mortality (min)	% Mortality protection
Control	4.50 ± 0.76	0.00	6.83 ± 0.91	0.00
S2 250	10.67 ± 2.06*	0.00	13.17 ± 2.20	0.00
S2 500	10.8 ± 1.02*	16.67	10.8 ± 1.02	16.67
S2 1000	9.83 ± 2.60*	0.00	15.5 ± 3.41**	0.00
VA 200	0.00	100	0.00	100

Control, distilled water, S2 sub-fraction; VA, sodium valproate was administered 30 min intraperitoneally before the injection of PTZ (85 mg/kg) subcutaneously. Values are the mean ± SEM, n = 6, one-way ANOVA df: 21, F: 3.07, α < 0.05 (seizure onset), *p < 0.05 and **p < 0.01 Dunnett post hoc test.

Figure 3. Effect of RAF (300 mg/kg) on mean seizure duration (MSD) in electrically induced kindling in adult rats.

Figure 4. Effect of RAF (300 mg/kg) on behavioral seizure scores (BSS) in electrically induced kindling in adult rats.

Figure 5. Effect of RAF (600 mg/kg) on mean seizure duration (MSD) in electrically induced kindling in adult rats.

Figure 6. Effect of RAF (600 mg/kg) on behavioral seizure scores (BSS) in electrically induced kindling in adult rats.

Figure 7. Effect of RAF (6, 12, and 20 μg/ml) on sodium (NaV 1.6) channels blockade at holding potential (VH) of −60 mV using human embryonic kidney cells (HEK cells 293) in electrophysiological studies. n = 5.