Behavioral and Biochemical Indices of Neurotoxicity in Jimson weed Administered Rats

This study examined the effect of alkaloid extracts from leaf and fruit of Jimson weed (Datura stramonium L; a toxic food contaminant of global reputation) on cognitive function, antioxidant status and activities of critical enzymes of monoaminergic and cholinergic systems of neurotransmission in rats. Alkaloid extracts were prepared by solvent extraction method. The gas chromatograph coupled with mass spectroscopic (GC-MS) characterization of the extracts was also carried out. Thereafter, rats were administered 100 and 200 mg/kg body weight (p.o) of extracts for thirty days. Prior to termination of the experiment, the rats were subjected to spontaneous alternation and hole-board behavioral tests. Thereafter, rats were sacrificed and activities of acetylcholinesterase (AChE), monoamine oxidase (MAO) and antioxidant enzymes (superoxide dismutase (SOD), glutathione-S-transferase (GST) and catalase), as well as malondialdehyde (MDA) and total thiol (TSH) contents of their brain homogenates were determined. The results showed that rats administered the extracts exhibited reduced memory index and also exhibited increased level of anxiety-like behavior. Furthermore, rats administered the extracts exhibited significantly reduced levels of brain AChE, MAO, SOD, catalase and GST activities, reduced amount of brain TSH and elevated brain MDA content compared to control. Results from the GC-MS characterization revealed the presence of hyoscyamine (atropine), scopolamine, amphetamine, cathine, phenlyephirine and Tropine trifluoroacetate among others in the extracts. Therefore, the alterations in cholinergic, monoaminergic and antioxidant systems in brain of rats administered fruit and leaf alkaloid extracts of Jimson weed could be one of the major biochemical mechanisms underlying their ability to induce impairment of cognitive functions which could be significantly linked to their constituent alkaloids

Effect of processing on in vitro glycemic indices and carbohydrate catabolizing enzyme inhibitory properties of some tropical grain legumes

Background: Glycemic index (GI) is often used as a measure of how a particular food can elicit rise in blood glucose and low GI foods have often been advocated as  therapeutically important in managing  hyperglycemia. Legumes are important staple foods especially in developing countries due to being cheap but rich sources of proteins. This study sought to investigate the effect of processing (roasting and boiling) on the glycemic indices, soluble sugar and starch contents as well as the α-amylase and α-glucosidase inhibitory properties of some tropical grain legumes; soybean (Glycine max (L.) Merrill), African yam bean (Spenostylis stenocarpa Harms) and bambara groundnut (Vigna subterranea (L.) Verdc).Methods: Each sample was divided into three portions; one portion was roasted, another boiled, while the last portion was not processed. Thereafter, the samples  were analyzed for their in vitro glycemic indices, soluble sugar and starch contents as well as, in vitro α-amylase and α-glucosidase inhibitory properties.Results: The result revealed that roasting caused a decrease in the glycemic indices, starch and sugar contents of the samples. In addition, roasting also caused an increase in the α-amylase and α-glucosidase inhibitory property of all samples.Conclusion: Hence, roasting of the legume grains appeared to be a better processing method in that it led to low soluble sugar and starch content, with a concomitant decrease in their glycemic indices as well as increased α-amylase and α- glucosidase inhibitory properties which are good qualities for potential  antidiabetic food and food components; nevertheless, roasted bambara groundnut appeared to be the most promising. Key words: Legume grains, Thermal processing, Glycemic response, Hyperglycemi

In vitro neuroprotective properties of some commonly consumed green leafy vegetables in Southern Nigeria

Green leafy vegetable is one of the major cuisines in Southern Nigeria and they are not only consumed for their palatability, but also for their nutritional and medicinal properties as reported in folklore. Notable among them are afang (Gnetum africanum), editan (Lasianthera africana) and utazi (Gongronema latifolium). In this study, we investigated the effect of aqueous extracts from afang, editan and utazi leaves on cholinesterases [acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)] and monoamine oxidase (MAO) activities. Fe2+ chelating abilities were also determined as an assessment of their neuroprotective potentials in vitro. We also assayed for their total phenol contents while the constituent phenolics were characterized using high performance liquid chromatography coupled with diode array detector (HPLC-DAD). The results revealed that the extracts inhibited AChE, BChE and MAO activities and also chelated Fe2+ in concentration dependent manner. The HPLC-DAD characterization showed that gallic, caffeic and ellagic acids and rutin were the dominant phenolic compounds in the extracts; nevertheless, utazi had the highest distribution of identified phenolics while afang had the least. The ability of the aqueous extracts of the vegetables to inhibit key enzymes (AChE, BChE and MAO) relevant to neurodegeneration, as well chelate metal ion could help suggest their possible neuroprotective properties. These vegetables could be use as dietary intervention in the management of neurodegenerative diseases such as Alzheimer's and Parkinson's diseases