Ultrasound-Microwave Combined Extraction of Novel Polysaccharide Fractions from Lycium barbarum Leaves and Their In Vitro Hypoglycemic and Antioxidant Activities

Effects of Separation and Purification Methods on Antioxidation, Hypoglycemic and DNA Protection Activity of Fenugreek Polysaccharide

Six low molecular weight fenugreek polysaccharides (FP) were isolated and purified by ethanol stepwise precipitation (EFP-20, EFP-40, and EFP-60) and DEAE-52 cellulose column method (DFP-0, DFP-0.15, and DFP-0.3), respectively. The effects of different separation and purification techniques on the preliminary properties and biological activities of fenugreek polysaccharides were compared. The results showed that the DEAE-52 cellulose-eluted fractions had a higher total sugar content and displayed a looser structure. The molecular weights of all six fractions were in the range of 4-19 kDa, with significant changes in the ratio of galactose to mannose. All six fractions contained α-D-galactopyranose and β-D-mannopyranose structures. Activity tests showed that all six fractions possessed antioxidant, hypoglycemic and DNA-protective activities. Among them, the DFP-0 fraction showed the highest activity. Overall, different isolation and purification methods lead to changes in the properties and bioactivities of FP, which provides a theoretical basis for the development and application of FP in functional foods and drugs.

Response Surface Optimization of Polysaccharides from Jaboticaba (Myrciaria cauliflora [Mart.] O.Berg) Fruits: Ultrasound-Assisted Extraction, Structure Properties, and Antioxidant/Hypoglycemic Activities

Ultrasound-assisted extraction (UAE) method proves to be more effective compared to traditional extraction methods. In the present study, response surface methodology (RSM) was used to determine the optimal process parameters for extracting polysaccharides (U-MCP) from jaboticaba fruit using UAE. The optimum extraction conditions were ultrasonic time 70 min, extraction temperature 60 °C, and power 350 W. Under these conditions, the sugar content of U-MCP was 52.8 %. The molecular weights of the ultrasound-assisted extracted U-MCP ranged from 9.52×102 to 3.27×103  Da, and consisted of five monosaccharides including mannose, galacturonic acid, glucose, galactose, and arabinose. Moreover, in vitro antioxidant and hypoglycaemic assay revealed that U-MCP has prominent anti-oxidant activities (1,1-diphenyl-2-picryl-hydrazyl (DPPH) radicals, hydroxyl radicals and 2,2'-Azinobis (3-ethylbenzothiazoline-6-sulfonic Acid Ammonium Salt) (ABTS) radicals scavenging activities) and hypoglycemic activities (α-amylase and α-glucosidase inhibition activities).

Bioactive Components of Lycium barbarum and Deep-Processing Fermentation Products

Lycium barbarum, a homology of medicine and food, contains many active ingredients including polysaccharides, polyphenol, betaine, and carotenoids, which has health benefits and economic value. The bioactive components in Lycium barbarum exhibit the effects of antioxidation, immune regulation, hypoglycemic effects, and vision improvement. Recently, the development of nutrition and health products of Lycium barbarum has been paid more and more attention with the increase in health awareness. A variety of nutrients and bioactive components in wolfberry can be retained or increased using modern fermentation technology. Through fermentation, the products have better flavor and health function, which better meet the needs of market diversification. The main products related to wolfberry fermentation include wolfberry fruit wine, wolfberry fruit vinegar, and lactic acid fermented beverage. In this review, the mainly bioactive components of Lycium barbarum and its deep-processing products of fermentation were summarized and compared. It will provide reference for the research and development of fermented and healthy products of Lycium barbarum.

New Insights into the Latest Advancement in α-Amylase Inhibitors of Plant Origin with Anti-Diabetic Effects

The rising predominance of type 2 diabetes, combined with the poor medical effects seen with commercially available anti-diabetic medications, has motivated the development of innovative treatment approaches for regulating postprandial glucose levels. Natural carbohydrate digestion enzyme inhibitors might be a viable option for blocking dietary carbohydrate absorption with fewer side effects than manufactured medicines. Alpha-amylase is a metalloenzyme that facilitates digestion by breaking down polysaccharides into smaller molecules such as maltose and maltotriose. It also contributes to elevated blood glucose levels and postprandial hyperglycemia. As a result, scientists are being urged to target α-amylase and create inhibitors that can slow down the release of glucose from carbohydrate chains and prolong its absorption, thereby resulting in lower postprandial plasma glucose levels. Natural α-amylase inhibitors derived from plants have gained popularity as safe and cost-effective alternatives. The bioactive components responsible for the inhibitory actions of various plant extracts have been identified through phytochemical research, paving the way for further development and application. The majority of the findings, however, are based on in vitro investigations. Only a few animal experiments and very few human investigations have confirmed these findings. Despite some promising results, additional investigation is needed to develop feasible anti-diabetic drugs based on plant-derived pancreatic α-amylase inhibitors. This review summarizes the most recent findings from research on plant-derived pancreatic α-amylase inhibitors, including plant extracts and plant-derived bioactive compounds. Furthermore, it offers insights into the structural aspects of the crucial therapeutic target, α-amylases, in addition to their interactions with inhibitors.

Extraction, Purification, Structural Characteristics, Health Benefits, and Application of the Polysaccharides from Lonicera japonica Thunb.: A Review

Lonicera japonica Thunb. is a widely distributed plant with ornamental, economic, edible, and medicinal values. L. japonica is a phytoantibiotic with broad-spectrum antibacterial activity and a potent therapeutic effect on various infectious diseases. The anti-diabetic, anti-Alzheimer's disease, anti-depression, antioxidative, immunoregulatory, anti-tumor, anti-inflammatory, anti-allergic, anti-gout, and anti-alcohol-addiction effects of L. japonica can also be explained by bioactive polysaccharides isolated from this plant. Several researchers have determined the molecular weight, chemical structure, and monosaccharide composition and ratio of L. japonica polysaccharides by water extraction and alcohol precipitation, enzyme-assisted extraction (EAE) and chromatography. This article searched in the Chinese Pharmacopoeia, Flora of China, Web of Science, PubMed, and CNKI databases within the last 12 years, using "Lonicera. japonica polysaccharides", "Lonicera. japonica Thunb. polysaccharides", and "Honeysuckle polysaccharides" as the key word, systematically reviewed the extraction and purification methods, structural characteristics, structure-activity relationship, and health benefits of L. japonica polysaccharides to provide insights for future studies. Further, we elaborated on the potential applications of L. japonica polysaccharides in the food, medicine, and daily chemical industry, such as using L. japonica as raw material to make lozenges, soy sauce and toothpaste, etc. This review will be a useful reference for the further optimization of functional products developed from L. japonica polysaccharides.