One way to evaluate the toxicity of natural extracts of medicinal plants is the Allium cepa assay. This in vitro test is very useful as a first-tier analysis of cytotoxicity and genotoxicity, because of the simplicity, low relative cost, versatility and minimum laboratory

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The study evaluated the effects of Pterocarpus mildbraedii leaf extracts on myocardial infarction induced by isoproterenol (ISO) in Wistar albino rats with a view to ascertain the value of its use in the management of heart-related diseases. Fresh plant leaves were collected, identified, extracted, fractionated and the aqueous layer partitioned with ethyl acetate. GC-MS was carried out on the ethyl acetate fraction (EAF) and unknown compounds were identified by comparing measured mass spectral data with those in NIST 14 Mass Spectral Library. Twenty-five adult rats were divided into five groups of 5 rats each. Groups I &II were the control groups. Rats in groups III-V were pretreated with 50 mg/kg and 100 mg/kg of EAF and 1.8 mg/kg of propranolol respectively for 21 days. Myocardial infarction was then induced in all the rats (except those in Group I) with the intraperitoneal injection of ISO (85 mg/kg) for 2 days. Afterwards, the rats were sacrificed and blood samples, heart homogenate and samples for histological studies were aseptically collected. Activities of cardiac biomarkers, lipid profile, enzymatic and non-enzymatic antioxidants were evaluated using standard methods. GC-MS analysis showed that the most abundant components of the plant are propionic acid, 2,3-dimethylphenyl ester, catechol, octyl-β-D-glucopyranoside, phenol and n-Hexadecanoic acid. Administration of ISO caused significant elevation of the activities of cardiac biomarkers (troponin-T concentrations, creatine kinase-MB and lactate dehydrogenase) while rats pretreated with EAF had significantly lower levels of the biomarkers. Moreover, alterations in lipid profile, enzymatic and non-enzymatic antioxidants brought about by the administration of ISO were ameliorated. Histological examinations revealed lesser degree of myocardial injury in pre-treated rats.

The study evaluated the biochemical effects of methanolic seed extract of Aframomum melegueta (MEAM) on biochemical parameters of the brain of rats treated with monosodium glutamate (MSG) with a view to considering the possibility of using the plant as a remedy for the management of neurotoxic disorders. MEAM was prepared according to standard methods, phytochemically screened and followed by evaluation of its antioxidant and anti-inflammatory potentials as well as its biological activities. Phytochemical screening of the methanolic extract (ME) revealed the presence of alkaloids, cardiac glycosides, flavonoids, saponins, steroids, tannins and terpenoids. Administration of MSG (2 g/kg bwt) caused alterations in the levels of glutathione, nitric oxide, Vitamin C and E, as well as in the reduction of activities of enzymatic antioxidants. There were increases in the activities of brain marker enzymes, protein and peroxidation levels. Histopathological observations of brain sections revealed that MEAM protected the brain from glutamate-induced neurotoxicity. Conclusively, extract of A. melegueta elicited appreciable and potent neuroprotective potentials against neuro-degeneration caused by MSG oral administration, in a concentration dependent manner.