No abstract

No abstract

Mani (2015) Enhancement of β-secretase inhibition and antioxidant activities of tempeh, a fermented soybean cake through enrichment of bioactive aglycones, Pharmaceutical Biology, 53:5, 758-766, DOI: 10.3109/13880209.2014 Context: Soybean and its fermented products are the most common source of isoflavones in human food.Objective: The present study quantifies the major glycosides and aglycones in soybean and its fermented product tempeh isoflavone extracts. The comparision of antioxidant effects and BACE1 inhibitory activity between the isoflavones of soybean and tempeh were also established. Materials and methods:The major isoflavones such as daidzein and genistein (aglycones), and their sugar conjugates (glycosides) daidzin and genistin in soybean and tempeh isoflavones were quantified using HPLC analysis. Comparative studies on BACE 1 (b-site amyloid precursor protein cleaving enzyme 1 or b-secretase 1) inhibition and free-radical scavenging activities (diphenyl-1-picrylhydrazyl (DPPH) and ferrous ion chelating ability) were conducted.Results: The amount of actives (mg/100 g) in soybean isoflavone compared with tempeh isoflavone is as follows: daidzein 16.72 mg/100 g versus 38.91 mg/100 g, genistein 11.10 mg/ 100 g versus 24.03 mg/100 g, daidzin 6.16 mg/100 g versus 0.69 mg/100 g, and genistin 24.61 mg/100 g versus 6.57 mg/100 g. The IC 50 values of soybean and tempeh isoflavones against BACE1 were 10.87 and 5.47 mg/ml, respectively. The tempeh isoflavone had a more potent DPPH free-radical scavenging activity (IC 50 ¼ 2.67 mg/ml) than the soybean isoflavone (IC 50 ¼ 10 mg/ml). The ferrous ion chelating ability of the isoflavones was practically similar (IC 50 ¼ 10.40 mg/ml, soybean and 11.13 mg/ml, tempeh). Discussion and conclusion: The present study indicates that tempeh is a healthy supplement to alleviate oxidative stress through the enrichment of aglycones.

Alzheimer's disease (AD) is characterized by signs of major oxidative stress and the loss of cholinergic cells. The present study was designed to investigate the role of the total alkaloidal extract from Murraya koenigii (MKA) leaves on age related oxidative stress and the cholinergic pathway in aged mice. Ascorbic acid (100 mg/kg, p.o.) was used as a standard drug. The MKA improved the level of protective antioxidants such as glutathione peroxidase (GPx), reduced glutathione (GSH), glutathione reductase (GRD), superoxide dismutase (SOD) and catalase (CAT) in brain homogenate at higher doses (20 and 40 mg/kg, p.o.). Moreover, a dose dependent decline was noted in lipid peroxidation (LPO) and the nitric oxide assay (NO) at all doses of MKA (10, 20 and 40 mg/kg, p.o.). Interestingly, significant progress was noted with the supplementation of MKA by an improvement of the acetylcholine (ACh) levels and a reduction in the acetylcholinesterase (AChE) activity in aged mouse brain. In addition, a significant elevation of serum albumin (ALBU), alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate transaminase (AST) and total protein as well as a decline in creatinine, total cholesterol, urea nitrogen and glucose levels with MKA also ameliorated the hepatic and renal functions in normal ageing process. The results showed the possible utility of Murraya koenigii leaves in neuroprotection against neurodegenerative disorders such as Alzheimer's disease.

Soybean and local fermented soybean, tempeh have been known for their health benefits and memory enhancement. It has been reported that soybean has potential role in reducing the progression of neurodegenerative disorder. Reactive oxygen species (ROS) play a crucial role in ageing and age-related neurodegenerative changes. The present study highlighted the comparative studies between total isoflavone extract from soybean and tempeh on the neuronal antioxidant. The total isoflavone extracts were administered orally for 15 days with three selected doses (10, 20 and 40 mg/kg). Piracetam (400 mg/kg, p.o.) was used as standard drug. The measurement of brain catalase, superoxide dismutase (SOD), glutathione (GSH), glutathione reductase (GR), TBARS and nitric oxide (NO) were extended. Our results showed that soybean and tempeh extracts significantly improved antioxidant activities by significantly increased the levels of catalase, SOD, GR and GSH while decreased levels of TBARS and NO level in the rat brain. This suggests that soybean and tempeh extract might be useful in the age-related neurodegenerative changes including management and prevention of Alzheimer's disease through its antioxidant activities.