Mangifera indica ‘Namdokmai’ Prevents Neuronal Cells from Amyloid Peptide Toxicity and Inhibits BACE-1 Activities in a Drosophila Model of Alzheimer’s Amyloidosis

Bioactive compounds and in vitro biological properties of Arthrospira platensis and Athrospira maxima: a comparative study

Cyanobacteria, especially Arthrospira, are valuable resources of nutrients and natural pigments with many beneficial health-related properties. This study optimized the extraction conditions of Arthrospira to achieve high phenolic contents and antioxidant activities. Under optimized extraction conditions, the bioactive compounds (phenolics and pigment components), antioxidant activities, and inhibitions of the key enzymes relevant to some non-communicable diseases were compared between Arthrospira platensis and Arthrospira maxima. Optimized extraction conditions were determined as 2 h shaking time, 50 °C extraction temperature, and 1% (w/v) solid-to-liquid ratio, giving effective phenolic and phycocyanin contents using aqueous extraction, while 80% (v/v) aqueous ethanolic extraction provided high total chlorophyll content. Most antioxidant activities were higher using 80% (v/v) aqueous ethanolic extracts. Both Arthrospira species inhibited the key enzymes involved in controlling non-communicable diseases including hyperlipidemia (lipase), diabetes (α-amylase, α-glucosidase, and dipeptidyl peptidase-IV), Alzheimer's disease (acetylcholinesterase, butyrylcholinesterase and β-secretase), and hypertension (angiotensin-converting enzyme). High inhibitory activities were detected against β-secretase (BACE-1), the enzyme responsible for β-amyloid plaque formation in the brain that acts as a significant hallmark of Alzheimer's disease. Arthrospira extract and donepezil (Alzheimer's disease drug) synergistically inhibited BACE-1, suggesting the potential of Arthrospira extracts as effective BACE-1 inhibitors. Interestingly, A. maxima exhibited higher bioactive compound contents, antioxidant activities, and key enzyme inhibitions than A. platensis, indicating high potential for future food and medicinal applications.

Phenolic content of Thai Bao mango peel and its in-vitro antioxidant, anti-cholinesterase, and antidiabetic activities

Plant phenolics have been known for various biological activities. This study aims to extract and examine the presence of phenolics in Bao mango (Mangifera indica L. var.) peel ethanolic extract (MPE). Further, antioxidant, anti-diabetic (α-amylase, and α-glucosidase inhibitory activity), and anti- Alzheimer's disease (AD) (acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and β-secretase (BACE-1) inhibitory activity) efficacy of MPE were determined. The results indicated that mangiferin (8755.89 mg/ 100 g extract) was the major phenolic compound in MPE. An antioxidant mechanism revealed that MPE had a higher radical scavenging ability (4266.70 µmol TE/g extract) compared to reducing power (FRAP) or oxygen radical absorption capacity (ORAC). Further in-vitro enzyme inhibitory assay against diabetic and AD involved enzymes showed that MPE had stronger inhibitory action against an enzyme involved in diabetes compared to their standard drug (Acarbose) (P < 0.05). While a lower IC50 value was observed against AD-involved enzymes compared to their standard drug (donepezil) (P < 0.05). The results show that Thai Bao mango peel byproduct can be a potential source of nutraceuticals to lower diabetes and improve cognitive health.

Optimized Conditions for the Extraction of Phenolic Compounds from Aeginetia indica L. and Its Potential Biological Applications

Aeginetia indica L., a parasitic root in the Orobanchaceae family, is used as a food colorant in traditional Thai desserts. However, scant information is available on its food applications as well as medicinal properties, while overharvesting by the local people has severely depleted wild plant populations. This research, thus, aimed to extract optimized total phenolic content (TPC) in varying extraction conditions using response surface methodology (RSM) and the Box-Behnken design (BBD). Results indicated that an extraction temperature of 90 °C, 80% (v/v) aqueous ethanol, and 0.5% (w/v) solid-to-liquid ratio yielded the highest TPC at 129.39 mg gallic acid equivalent (GAE)/g dry weight (DW). Liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) identified the predominant phenolics as apigenin (109.06 mg/100 g extract) and luteolin (35.32 mg/100 g extract) with trace amounts of naringenin and rutin. Under the optimal extraction condition, the plant extract exhibited antioxidant activities of 5620.58 and 641.52 µmol Trolox equivalent (TE)/g DW determined by oxygen radical absorbance capacity (ORAC) and ferric ion reducing antioxidant power (FRAP) assay, while the scavenging capacity of total radicals at 50% (SC50) was determined to be 135.50 µg/mL using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The plant extract also exhibited inhibitory activities against the key enzymes relevant to type II diabetes, obesity, and Alzheimer's disease, suggesting the potential for medicinal applications.

Recent advancements in the role of phytochemicals and medicinal plants in prophylaxis and management of Alzheimer's disease

Medicinal plants and phytochemicals are some of the major sources in the treatment of various neurodegenerative disorders including Alzheimer's disease (AD). There is no FDA-approved drug to target AD pathology directly. Full cognitive restoration and management of psychosis-like symptoms are still to be achieved. Being comparatively safer with fewer side effects, medicinal plants have been among the major areas of interest to be researched. Several mechanistic pathways are involved in AD including anticholinesterase activity, glutamate toxicity, free radicals generation, Amyloid β (Aβ) toxicity, inflammation, and mitochondrial dysfunction. Various phytochemicals such as paenol, andrographolide, isoquercitrin, flavonoids, and saponins obtained from different plant sources, various medicinal plants like Spirulina maxima, Salicornia europaea, Curcuma longa, Citrus Junos Tanaka, Cassiae semen, Centella asiatica as well as various traditional medicinal plants of China, Asia, Europe, Turkey, and Iran have been found effective against one or more of these targets. Large numbers of clinical trials are under process to evaluate the role of different phytoconstituents in AD management. Out of 143 agents under clinical trials, 119 have been categorized as disease-modifying agents. The present review extensively covers the recent advancements in the usage of phytochemicals and medicinal plants in various experimental AD models. It involves clinical trials and other research works divided into three sections, including those performed in vitro, in vivo, and in humans mainly from the last five years along with disease markers and mechanistic pathways involved. However, phytochemicals should be explored further in order to achieve neurorestoration in AD.

Exploring the efficient natural products for Alzheimer's disease therapy via Drosophila melanogaster (fruit fly) models

Alzheimer's disease (AD) is a grievous neurodegenerative disorder and a major form of senile dementia, which is partially caused by abnormal amyloid-beta peptide deposition and Tau protein phosphorylation. But until now, the exact pathogenesis of AD and its treatment strategy still need to investigate. Fortunately, natural products have shown potential as therapeutic agents for treating symptoms of AD due to their neuroprotective activity. To identify the excellent lead compounds for AD control from natural products of herbal medicines, as well as, detect their modes of action, suitable animal models are required. Drosophila melanogaster (fruit fly) is an important model for studying genetic and cellular biological pathways in complex biological processes. Various Drosophila AD models were broadly used for AD research, especially for the discovery of neuroprotective natural products. This review focused on the research progress of natural products in AD disease based on the fruit fly AD model, which provides a reference for using the invertebrate model in developing novel anti-AD drugs.

Phenolic Profiles and Bioactivities of Ten Original Lineage Beans in Thailand

Legumes and pulses are important food components with various phytochemicals and health benefits. However, the health-related bioactivities of some underutilized species remain uninvestigated. To breed a new bean lineage with particular health-related properties, this study investigated phenolics (specifically, isoflavones) and the in vitro inhibitory activities of the enzyme relevant to some non-communicable diseases in underutilized cultivars of Phaseolus lunatus (lima beans), compared to the commonly consumed P. vulgaris (red kidney bean) and beans in the Glycine and Vigna genera. The results indicated that soybeans in the Glycine genus contained the highest isoflavone contents, especially glycitein (1825-2633 mg/100 g bean) and daidzein (1153-6471 mg/100 g bean), leading to potentially higher enzyme inhibitory activities (25-26% inhibition against α-amylase, 54-60% inhibition against α-glucosidase, 42-46% inhibition against dipeptidyl peptidase IV, 12-19% inhibition against acetylcholinesterase and 20-23% inhibition against butyrylcholinesterase) than those from other genera. Interestingly, lima beans with low isoflavone content (up to 2 mg/100 g bean) still possessed high inhibitory activities against lipase (12-21% inhibition) and β-secretase (50-58% inhibition), suggesting that bioactive compounds other than the isoflavones might be responsible for these activities. Isoflavone contents and enzyme inhibitory activities in Vigna beans were diverse, depending on the particular cultivars. The information gained from this study can be used for further investigation of bioactive components and in-depth health properties, as well as for future breeding of a new lineage of bean with specific health potentials.