Polyphenolic-Protein-Polysaccharide Complexes from Hovenia dulcis: Insights into Extraction Methods on Their Physicochemical Properties and In Vitro Bioactivities

Abstract

Seven extraction methods, including hot water extraction (HWE), pressurized water extraction (PWE), ultrasound-assisted extraction, microwave-assisted extraction, ultrasound-assisted enzymatic extraction, high-speed shearing homogenization extraction, and ultrasound-microwave-assisted extraction, were utilized to extract polyphenolic-protein-polysaccharide complexes (PPPs) from Hovenia dulcis. Next, their physicochemical properties and in vitro antioxidant activities, antiglycation effects, and inhibition activities on α-glucosidase and α-amylase were studied and compared. The findings from this study indicate that various extraction processes exhibit notable influences on the physicochemical properties and in vitro bioactivities of PPPs. Extraction yields, contents of polyphenolics and flavonoids, apparent viscosities, molecular weights, molar ratios of monosaccharide compositions, and ratios of amino acid compositions in PPPs varied in different extraction methods. Furthermore, 13 phenolic compounds in PPPs, including rutin, myricitrin, myricetin, quercetin, kaempferol, protocatechuic acid, gallocatechin, p-hydroxybenzoic acid, ampelopsin, quercetin-7,4′-diglucoside, dihydroquercetin, 5-methylmyricetin, and naringenin, were identified. The relatively strong in vitro antioxidant activities, antiglycation effects, and inhibition activities on α-glucosidase and α-amylase were determined in both PPP-W and PPP-P obtained by HWE and PWE, respectively. The high content of total polyphenolics may be one of the main contributors to their in vitro bioactivities. The findings have shown that the PWE method can be an appropriate method to prepare PPPs with strong bioactivities for application in the functional food industry.

Structural and Biological Properties of Water Soluble Polysaccharides from Lotus Leaves: Effects of Drying Techniques

“…Additionally, the high degree of esterification of pectic-polysaccharides might contribute to their high inhibitory effects on digestive enzymes [ 41 ]. Furthermore, the high content of bound polyphenolics may also contribute to the high inhibitory effects of natural polysaccharides against digestive enzymes [ 14 , 18 , 42 ]. Therefore, in the present study, the lower molecular weight distribution, higher degree of esterification, and higher content of bound polyphenolics of LLP-M might contribute to its stronger inhibitory effect on α-glucosidase.…”

Hovenia dulcis Thumberg: Phytochemistry, Pharmacology, Toxicology and Regulatory Framework for Its Use in the European Union

“…It was also reported that myricetin was the most promising compound since its activity was more effective than acarbose [52]. The in vitro inhibitory activity against α-amylase and α-glucosidase enzymes was also demonstrated for H. dulcis extract, mainly composed of polysaccharides, and their bioactivity was affected by the extraction method [73][74][75]. The antidiabetic effect was investigated and proven also on different in vivo models of diabetic mice and rats [53,[76][77][78].…”

“…Both in vitro and in vivo studies have demonstrated the antidiabetic effect of H. dulcis extracts. Different in vitro studies reported the inhibitory effect of crude extracts against α-amylase and α-glucosidase [ 52 , 73 , 74 , 75 ]. Meng et al [ 52 ] showed that total flavonoids, myricetin and quercetin obtained from H. dulcis ethanol seeds extract have an inhibitory effect on α-amylase and α-glucosidase.…”

Changes in Physicochemical and Biological Properties of Polyphenolic-Protein-Polysaccharide Ternary Complexes from Hovenia dulcis after In Vitro Simulated Saliva-Gastrointestinal Digestion

“…Hovenia dulcis (Rhamnaceae), commonly known as Japanese grape, 'Guai Zao' and 'Zhi Ju', is native to East Asia such as Japan, Korea, and China [1]. It is a delicious and sweet fruit, and it is also widely used as a functional food and a traditional Chinese herb in China [2]. Generally, H. dulcis has a long history been used as a traditional Chinese herb for the treatment of liver disease and alcohol poisoning [1,2].…”

“…It is a delicious and sweet fruit, and it is also widely used as a functional food and a traditional Chinese herb in China [2]. Generally, H. dulcis has a long history been used as a traditional Chinese herb for the treatment of liver disease and alcohol poisoning [1,2]. Recently, a numerous number of in vitro and in vivo studies have demonstrated that H. dulcis possesses diverse health-promoting effects, such as anti-diabetic, anti-cancer, anti-oxidant, antiinflammatory, and hepatoprotective effects [3,4].…”