Protective Effect of Dalbergia sissoo Extract Against Amyloid-β (1-42)-induced Memory Impairment, Oxidative Stress, and Neuroinflammation in Rats

Effect of Dalbergiella welwitschi alkaloid-rich leaf extracts on testicular damage in streptozotocin-induced diabetic rats

Diabetes mellitus is a chronic disease affecting young and old, even though it can be managed with orthodox medicine, which has a series of side effects. Therefore, Dalbergiella welwitschi is one of the medicinal plants that is commonly used for the management of diabetes mellitus and its associated complications. Hence, this study was designed to assess the testicular-protective ability of alkaloid-rich leaf extract of D. welwitschi in streptozotocin-induced type 2 diabetic rats D. welwitshii leaf alkaloid-rich extract was obtained using standard procedure. Streptozotocin was injected into the experimental animals intraperitoneally at a dose of 45 mg/kg body weight to induce type 2 diabetes mellitus. Prior to this, the animals were given 20% (w/v) fructose for one week. Thus, the animals were grouped into five (n = 8), comprising of un-induced rats (NC), diabetic control (DC), diabetic rats treated with low (50 mg/kg body weight) and high (100 mg/kg body weight) doses of D. welwitschi alkaloid-rich leaf extracts (i.e., DWL and DWH respectively) and 200 mg/kg body weight dose of metformin (MET). The animals were sacrificed on the 21st day, blood and testis were harvested and used for the determination of ions (Fe, Cu and Zn), sialic acid, some hormones (testosterone, luteinizing and follicle stimulating), oxidative stress biomarkers [malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and glutathione (GSH)] as well as histological examination. In addition, the results show that diabetic rats placed on DWL, and DWH significantly (p < 0.05) decreased ion levels (Fe, Cu and Zn) and ameliorated oxidative stress biomarkers such as MDA, SOD, CAT, GPx, GST, and GSH. These were supported by the histological examination by improving testicular-protective effects in diabetic rats administered DWL, and DWH. Therefore, it is that assume that the alkaloid-rich leaf extracts of D. welwitschi may offer potential benefits in the treatment of diabetic testicular dysfunction.

Unveiling the neuroprotective properties of isoflavones: current evidence, molecular mechanisms and future perspectives

Neurodegenerative diseases encompass a wide range of debilitating and incurable brain disorders characterized by the progressive deterioration of the nervous system's structure and function. Isoflavones, which are naturally occurring polyphenolic phytochemicals, have been found to regulate various cellular signaling pathways associated with the nervous system. The main objective of this comprehensive review is to explore the neuroprotective effects of isoflavones, elucidate the underlying mechanisms, and assess their potential for treating neurodegenerative disorders. Relevant data regarding isoflavones and their impact on neurodegenerative diseases were gathered from multiple library databases and electronic sources, including PubMed, Google Scholar, Web of Science, and Science Direct. Numerous isoflavones, including genistein, daidzein, biochanin A, and formononetin, have exhibited potent neuroprotective properties against various neurodegenerative diseases. These compounds have been found to modulate neurotransmitters, which in turn contributes to their ability to protect against neurodegeneration. Both in vitro and in vivo experimental studies have provided evidence of their neuroprotection mechanisms, which involve interactions with estrogenic receptors, antioxidant effects, anti-inflammatory properties, anti-apoptotic activity, and modulation of neural plasticity. This review aims to provide current insights into the neuroprotective characteristics of isoflavones and shed light on their potential therapeutic applications in future clinical scenarios.

Polyphenolic Contents, Free Radical Scavenging and Cholinesterase Inhibitory Activities of Dalbergiella welwitschii Leaf Extracts

A decoction of Dalbergiella welwitschii leaves has been used ethnomedicinally for the treatment of mental illness and inflammatory diseases amongst other diseases. In this study, the leaf methanol extract of D. welwitschii and its partition fractions: n-hexane, ethyl acetate and aqueous, were tested and evaluated for their polyphenolic contents, free radical scavenging and cholinesterase inhibitory activities. The total phenolic (TPC), flavonoid (TFC) and proanthocyanidin (TPA) contents were determined using standard colorimetric methods. The anti-radical activity of the extracts against the 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric ion and nitric oxide (NO) radicals as well as their effects on lipid peroxidation were monitored spectrophotometrically. The cholinesterase enzyme (AChE and BuChE) inhibitions by the extracts were determined by a modified method of Ellman. The result showed a concentration-dependent increase in inhibition of the free radicals and the cholinesterase enzymes, except for that of lipid peroxidation. The ethyl acetate (EtOAc) fraction exhibited the highest polyphenolic contents among the fractions, with a TPC of 1.08 mgGAE/g, TFC of 0.38 mgQuE/g and TPA of 0.21 mgGAE/g. It also demonstrated the highest free radical scavenging activities with 72.63% and 65.43% inhibitions of DPPH and NO, respectively. The EtOAc fraction inhibited AChE and BuChE enzymes with IC₅₀ values of 0.94 and 8.49 mg/mL, respectively. Our findings show that the plant may have polyphenol contents, in particular in the methanol extract and EtOAc fraction. These extracts showed considerable free radical scavenging and cholinesterase inhibitory properties. Thus, the observed bioactivities may serve as a justification for its folkloric use as a remedy for mental illness. The study also provides relevant information that could help in the search for lead cholinesterase inhibitors from medicinal plants that can be exploited against neurodegenerative disorders.