Effect of Ethanolic Extract of Indigofera tinctoria on Chemically-Induced Seizures and Brain GABA Levels in Albino Rats

OBJECTIVES

Indigofera tinctoria Linn. of Fabaceae family is claimed to be useful to control epileptic seizures in the Indian system of folkore medicine. This study was designed to evaluate tinctoria and to verify the claim.

MATERIALS AND METHODS

Seizures were induced in male albino rats with pentylenetetrazole (PTZ). The test group animals were administered ethanolic extract of Indigofera tinctoria (EEIT) orally. The time of onset and duration of clonic convulsions were recorded. Maximal electroshock seizures (MES) were induced in animals. The duration of hind limb tonic extension (HLTE) was recorded. GABA levels and GABA transaminase activity in brain were estimated.

RESULTS

In PTZ model, EEIT significantly (P< 0.01, P< 0.001) delayed the onset of convulsions and reduced the duration of seizures in a dose dependent manner. A significant (P< 0.05) reduction in the duration of HLTE at higher doses of EEIT was observed in MES model. Increase in brain GABA levels was observed on treatment with EEIT at 500 and 1000 mg/kg doses, suggested that the plant may be acting by facilitating GABAergic transmission. A significant reduction (P< 0.05) in the activity of brain GABA transaminase was observed at higher doses. No neurotoxic signs were observed with rotarod test, pentobarbital induced sleeping time, locomotor activity and haloperidol-induced catalepsy.

CONCLUSION

The ethanolic extract of tinctoria was found to be useful to control and treat the variety of seizures.

Anticonvulsant Activity of Teucrium polium Against Seizure Induced by PTZ and MES in Mice

Teucrium polium (Labiatae) is a plant that widely grows in Iran. Some of species of Teucrium are used for a considerable range of actions in traditional medicine and T. polium has frequently been used as anticonvulsant. In this study, we investigated the protective effects of T. polium ethanolic aqueous extracts and related fractions on seizures induced by pentylenetetrazole (PTZ) and maximal electroshock stimulation (MES). Moreover, presence of alkaloids, terpenoids, tannins and flavonoid contents were evaluated. It was found that aqueous extract (ED50 = 22.4 mg/kg body weight) and related n-butanol fraction (ED50 = 12.6 mg/kg body weight) have antiseizure effects comparing to control groups. There was no difference between preventing of PTZ-induced death and MES-induced hindlimb tonic extension (HLTE) in ethanolic extract comparing to control groups. Our results showed that the amount of flavonoid quantity present in aqueous extract is higher than that of ethanolic extract. These data also showed that the quantity of the flavonoid in n-butanol fraction of aqueous extract is more than other fractions. In conclusion, it was realized that flavonoid rich extracts are more potent than other fractions in showing antiseizure effects.

MPEP reduces seizure severity in Fmr-1 KO mice over expressing human Abeta

Metabotropic glutamate receptor 5 (mGluR(5)) regulates the translation of amyloid precursor protein (APP) mRNA. Under resting conditions, mRNA is bound to and translationally repressed by the fragile X mental retardation protein (FMRP). Upon group 1 mGluR activation, FMRP dissociates from the mRNA and translation ensues. APP levels are elevated in the dendrites of primary neuronal cultures as well as in synaptoneurosomes (SN) prepared from embryonic and juvenile fmr-1 knockout (KO) mice, respectively. In order to study the effects of APP and its proteolytic product Abeta on Fragile X syndrome (FXS) phenotypes, we created a novel mouse model (FRAXAD) that over-expresses human APPSwe/Abeta in an fmr-1 KO background. Herein, we assess (1) human APP(Swe) and Abeta levels as a function of age in FRAXAD mice, and (2) seizure susceptibility to pentylenetetrazol (PTZ) after mGluR(5) blockade. PTZ-induced seizure severity is decreased in FRAXAD mice pre-treated with the mGluR(5) antagonist MPEP. These data suggest that Abeta contributes to seizure incidence and may be an appropriate therapeutic target to lessen seizure pathology in FXS, Alzheimer's disease (AD) and Down syndrome (DS) patients.