Anticonvulsant and related neuropharmacological effects of the whole plant extract of Synedrella nodiflora (L.) Gaertn (Asteraceae)

Abstract

Purpose: The plant Synedrella nodiflora (L) Gaertn is traditionally used by some Ghanaian communities to treat epilepsy. To determine if this use has merit, we studied the anticonvulsant and other neuropharmacological effects of a hydro-ethanolic extract of the whole plant using murine models.

Materials and methods: The anticonvulsant effect of the extract (10-1000 mg/kg) was tested on the pentylenetetrazole-, picrotoxin-, and pilocarpine-induced seizure models and PTZ-kindling in mice/rats. The effect of the extract was also tested on motor coordination using the rota-rod.

Results: The results obtained revealed that the extract possesses anticonvulsant effects in all the experimental models of seizures tested as it significantly reduced the latencies to myoclonic jerks and seizures as well as seizure duration and the percentage severity. The extract was also found to cause motor incoordination at the higher dose of 1000 mg/kg.

Conclusions: In summary, the hydro-ethanolic extract of the whole plant of S. nodiflora possesses anticonvulsant effects, possibly through an interaction with GABAergic transmission and antioxidant mechanisms and muscle relaxant effects. These findings thus provide scientific evidence in support of the traditional use of the plant in the management of epilepsy.

Keywords: Kindling; Synedrella nodiflora; pentylenetetrazole; picrotoxin; pilocarpine.

Figure 1a

Effect of SNE (100–1000 mg/kg) and phenobarbitone (3–30 mg/kg) on the latencies to myoclonic jerks induced by PTZ. Each column represents the mean ± SEM (n = 5). ^*P < 0.05, ^***P < 0.001 compared with vehicle-treated group (one-way analysis of variance followed by Newman–Keuls post hoc test)

Figure 1b

Effect of SNE (100–1000 mg/kg) and phenobarbitone (3–30 mg/kg) on the latencies to seizures induced by PTZ. Each column represents the mean ± SEM (n = 5). ^*P < 0.05, ^***P < 0.001 compared with vehicle-treated group (one-way analysis of variance followed by Newman–Keuls post hoc test)

Figure 2

Effect of SNE (100–1000 mg/kg) and phenobarbitone (3–30 mg/kg) on the total duration of the seizures induced by PTZ. Each column represents the mean ± SEM (n = 5). ^**P < 0.01 compared with vehicle-treated group (one-way analysis of variance followed by Newman–Keul's post hoc test)

Figure 3

Effect of SNE (100–1000 mg/kg) (a) and phenobarbitone (3–30 mg/kg) on the latency to myoclonic jerks and seizures induced by PIC. Each column represents the mean ± SEM (n=5). ^*P < 0.05, ^**P < 0.01, ^***P < 0.001 compared with vehicle-treated group (one-way analysis of variance followed by Newman–Keul's post hoc test)

Figure 4

Effect of SNE (100–1000 mg/kg) and phenobarbitone (3–30 mg/kg) on the frequency (a) and duration (b) of the convulsions induced by PIC. Each column represents the mean ± SEM (n=5). ^*P < 0.05, ^***P < 0.001 compared with vehicle-treated group (one-way analysis of variance followed by Newman–Keul's post hoc test)

Figure 5

Effect of SNE (100–1000 mg/kg) (a) and diazepam (1–10 mg/kg) (b) on the latency to and total duration of seizures induced by PILO. Each column represents the mean ± SEM (n=6). ^*P < 0.05, ^**P < 0.01, ^***P < 0.001 compared with vehicle-treated group (one-way analysis of variance followed by Newman–Keuls post hoc test)

Figure 6

The dose–response effects of SNE (100–1000 mg/kg) (a and b) and DZP (0.1–1.0 mg/kg) (c and d) on the PTZ-kindled rats. The left panels show the time course of effects over the 32-day period and the right panels show the percent severity of seizures calculated from the AUCs for the test duration. Values are means ± SEM (n=5). ^*P < 0.05, ^** P < 0.01, ^***P < 0.001 compared with vehicle-treated group (two-way analysis of variance followed by Bonferroni's post hoc test). †P<0.05, †††P<0.001 compared with vehicle-treated group (one-way analysis of variance followed by Newman–Keul's post hoc test)

Figure 7

The dose–response effects of SNE (10–1000 mg/kg) (a and b) and baclofen (1–10 mg/kg) (c and d) on the rota-rod. The left panels show the time course of the time spent on the rotating rod at 24 rpm over a 120-min period and the right panels show the motor coordination effect calculated from the AUCs of the time course curves. Values are means ± SEM (n=5). ^**P < 0.01, ^***P < 0.001 compared with vehicle-treated group (two-way analysis of variance followed by Bonferroni's post hoc test). ††P < 0.01 compared with vehicle-treated group (one-way analysis of variance followed by Newman–Keul's post hoc test)

Figure 8

Percentage inhibition of PTZ induced lipid peroxidation in PTZ-kindled rats by SNE (100–1000 mg/kg) and diazepam (0.1–1.0 mg/kg). Each point represents the mean ± SEM (n=5)