[Investigating the anti-epileptic and sedative effects of hydroalcoholic extract of Melissa officinalis [Lemon balm] leaf on pentylenetetrazol induced epileptiform seizures in wistar rat]

Since long lasting administration of anti-seizure drugs produces undesirable side effects, many efforts have been made during recent decades to find and replace the chemical drugs by medicinal plants. The aim of present study was to study the antiepileptic [anti-seizure] effects of hydroalcoholic extract of Melissa officinalis on experimental epileptiform seizures, induced by pentylenetetrazol [PTZ] in Wistar rat. After normalization, rats in experimental groups 1, 2 and 3 were injected [i.p] 50, 80 and 120 mg/kg hydroalcoholic extract of Melissa officinalis, respectively. Control animals were injected extract solvent as the same manner. After 30 minutes all rats were injected [i.p] 80 mg/kg PTZ and then examined for epileptiform behaviors for the next 60 minutes. The rate of mortality during the next 24 hour was also recorded. In comparison with control group, in all experimental groups the latent period of tonic-clonic generalized seizure was significantly [P < 0.05] increased. Moreover, the mortality rate was decreased from 90% in control group to 30, 50 and 60% in experimental groups 1, 2 and 3, respectively. It can be concluded that hydroalcoholic extract of Melissa officinalis has potential sedative and anticonvulsant effects and probably exerts its effects through GABAergic system

[Evaluating the protective effects of melissa officinalis on learning deficits of rat's offspring exposed to lead acetate during pre-and postnatal periods]

Lead contamination dramatically influences different body systems especially the central nervous system. Lead absorption during gestational period has deleterious effects on fetal differentiation and development and it may possibly result in learning deficits in adulthood. Recent studies have demonstrated positive effects of Melissa officinalis on memory improvement in some neural disorders. The aim of the present study is to investigate the protective effects of Melissa on learning deficits in lead acetate exposed rats. In this experimental study in department of Biology, Faculty of Sciences, Ferdowsi University of Mashhad [2008-2009], 40 mated Wistar rats were divided into 8 groups as follows: control, negative control [Pb], Melissa [M] and Pb+M, and each in 3 different subgroups. The treatment started from the 7th day of gestation and continued during pregnancy and lactation. The learning ability and memory retention of four months old offspring were tested by complex T-maze. The collected data was analyzed by the SPSS software using one-way ANOVA and Toki test. A significant difference was found between lead exposed group and other groups regarding the time to reach the goal and the number of errors; while there was no meaningful difference between the control and other experimental groups. In lead exposed rats, learning deficits were obviously noticed. Since there was meaningful difference between control and Pb+M subgroups, Melissa can possibly improve learning deficits in lead acetate exposed rats