Studies on effects of Emblica officinalis (Amla) on oxidative stress and cholinergic function in scopolamine induced amnesia in mice.

Emblica officinalis, commonly known as amla, is an important medicinal plant of India. Its fruits have potent antioxidant activity due to the presence of tannoids, tannins, vitamin C and flavonoids. The aim of this study was to investigate the beneficial effect of the hydroalcoholic extract of the fruits of Emblica officinalis (EO) on memory impairment in Swiss albino mice. Scopolamine (1 mg kg-1, i.p) was administered to induce amnesia and the memory was evaluated by using elevated plus-maze and passive avoidance tests. Piracetam (200 mg kg-1, i.p.) was used as a standard nootropic agent. The EO extract was administered intraperitoneally in four graded doses (150, 300, 450 and 600 mg kg-1) for 7 consecutive days to different groups of mice. The mice were sacrificed on the 8th day following assessment of memory. The brain malondialdehyde (MDA) and glutathione (GSH) as well as acetylcholinesterase (AchE)) activity was determined. It was observed that EO extract reversed the amnesia induced by scopolamine. The mean transfer latency and retention latency in the EO extract 600 mg kg-1 group vs the vehicle treated scopolamine group was 13.46 sec (p<0.001) and 134.4 sec (p<0.001) vs 23.99 sec and 44.55 sec, respectively. EO extract treatment also significantly (p<0.001) ameliorated the oxidative stress induced by scopolamine administration. The mice brain MDA and GSH levels in the EO extract 600 mg kg-1 group vs the scopolamine group were 29.95 nmol g-1 of wet tissue and 51.87 μg g-1 tissue vs 55.22 nmol g-1 of wet tissue and 28.33 μg g-1 tissue, respectively. Further, EO extract (300, 450 and 600 mg kg-1, i.p) significantly (p<0.001) reversed the rise in brain acetyl cholinesterase (AchE) level induced by scopolamine. The mice brain AchE levels in the EO extract 600 mg kg-1 group as compared to the scopolamine group was 70.23 vs 151.49 U mg-1 protein-1, respectively. These results suggest that EO possesses memory enhancing, antioxidant and anti-cholinesterase activity. It may be useful for the treatment of cognitive impairments induced by cholinergic dysfunction. Its potential in the management of dementia and Alzheimer disease needs to be further explored.

Cardioprotective effects of Commiphora mukul against isoprenaline-induced cardiotoxicity: A biochemical and histopathological evaluation.

Commiphora mukul commonly known as Guggul is one of the oldest and commonly consumed herb for promoting heart and vascular health. Present study was undertaken to evaluate cardioprotective potential of Commiphora mukul against isoprenaline-induced myocardial necrosis in rats. Wistar albino rats were divided into three main groups: sham (saline only), isoprenaline control (saline and isoprenaline) and Commiphora mukul treated (Commiphora mukul and isoprenaline) groups. Commiphora mukul was administered in three doses 100, 200 and 400 mg kg-1 p.o. for 30 days. On 29th and 30th day, the animals of isoprenaline control and Commiphora mukul pretreatment groups were administered isoprenaline (85 mg kg-1; s.c.), consecutively at an interval of 24 hr. Isoprenaline administration produced a significant (p<0.05) decrease in myocardial antioxidants; superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSHPx), reduced glutathione (GSH), and myocyte injury marker enzymes creatine- phosphokinase - MB (CK-MB) and lactate dehydrogenase (LDH) along with enhanced lipid peroxidation; malondialdehyde (MDA) in heart. Commiphora mukul pretreatment reversed the isoprenaline-induced oxidative changes in rat myocardium by significant (p<0.05) increase in SOD, CAT, GSHPx, GSH and reduction of MDA. In addition to improving myocardial antioxidant status, Commiphora mukul also prevented the leakage of LDH and CK-MB from heart. Further, histopathological examination showed the reduction of necrosis, edema and inflammation following Commiphora mukul pretreatment. Based on present findings, it is concluded that Commiphora mukul may be a potential preventive and therapeutic agent against the oxidative stress associated ischemic heart disease owing to antioxidant and antiperoxidative activity.

Effect of Inula racemosa root extract on cardiac function and oxidative stress against isoproterenol-induced myocardial infarction.

The cardioprotective potential of Inula racemosa root hydroalcoholic extract against isoproterenol-induced myocardial infarction was investigated in rats. The rats treated with isoproterenol (85 mg/kg, s.c.) exhibited myocardial infarction, as evidenced by significant (P<0.05) decrease in mean arterial pressure, heart rate, contractility, relaxation along with increased left ventricular end diastolic pressure, as well as decreased endogenous myocardial enzymatic and non-enzymatic antioxidants. Isoproterenol also significantly (P<0.05) induced lipid peroxidation and increased leakage of myocyte injury marker enzymes. Pretreatment with I. racemosa extract (50, 100 or 200 mg/kg per day, p.o.) for 21 consecutive days, followed by isoproterenol injections on days 19th and 20th significantly (P<0.05) improved cardiac function by increasing the heart rate, mean arterial pressure, contractility and relaxation along with decreasing left ventricular end diastolic pressure. Pretreatment with I. racemosa also significantly (P<0.05) restored the reduced form of glutathione and endogenous antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase from the heart, which were depleted after isoproterenol administration. In addition to restoration of antioxidants, I. racemosa significantly (P<0.05) inhibited lipid peroxidation and prevented the leakage of myocytes specific marker enzymes creatine phosphokinase-MB and lactate dehydrogenase from the heart. Thus, it is concluded that I. racemosa protects heart from isoproterenol-induced myocardial injury by reducing oxidative stress and modulating hemodynamic and ventricular functions of the heart. Present study findings demonstrate the cardioprotective effect of I. racemosa and support the pharmacological relevance of its use and cardioprotection mechanism in ischemic heart disease as well as substantiate its traditional claim

Hydroalcoholic extract of Emblica officinalis Gaertn. affords protection against PTZ-induced seizures, oxidative stress and cognitive impairment in rats.

The cognitive impairment seen in epileptics may be a consequence of either the underlying epileptogenic process alone or it could manifest on account of the use of antiepileptic drugs that cause cognitive impairment as an adverse effect or both. Thus, there is a need for drugs that can suppress epileptogenesis without contributing to or , if possible, by acting to prevent the development of cognitive impairment. Emblica officinalis, an Indian medicinal plant, has marked antioxidant property. The effect of seven days pretreatment of 300, 500 and 700 mg/kg doses of hydroalcoholic extract of E. officinalis (HAEEO) administered intraperitoneally to rats was evaluated on pentylenetetrazole (PTZ) induced seizures, cognitive deficit and oxidative stress markers viz malondialdehyde (MDA) and glutathione. The 500 and 700 mg/kg ip doses of HAEEO completely abolished the generalized tonic seizures and also improved the retention latency in passive avoidance task. Further, HAEEO dose-dependently ameliorated the oxidative stress induced by PTZ. These findings suggest the potential of HAEEO to be used as an adjuvant to treatment with antiepileptic drugs.