Resin glycosides in aerial parts of Ipomoea batatas are potent lipase inhibitors: potential upcycling of sweet potato by-products to combat obesity

Abstract

Sweet potato (Ipomoea batatas) is a staple food crop that is cultivated globally. While the tubers are widely utilised in the food industry, 95 – 98% of sweet potato leaves...

Sweet potato extract alleviates high-fat-diet-induced obesity in C57BL/6J mice, but not by inhibiting pancreatic lipases

“…In the present study, we prepared SPE and found that SPE can inhibit PL activity in a dose-dependent manner. This is in agreement with our previous work ( 12 ). A PL inhibition of 20–70% was measured with SPE concentrations at 20–150 μg/ml by turbidity assay ( Figures 1A,B ) and 15–70 μg/ml by pNPP assay ( Figures 1C,D ).…”

“…The obesity-associated disturbances in mice included the impairment of glucose homeostasis and lipid metabolism, enlarged adipocytes and hepatic steatosis, which were detected by measuring murine adipose tissue, liver, feces, and blood. The previous work from our lab found that the PL activity was inhibited notably by SPE as evidenced by in vitro assays ( 12 ). Since orlistat presents as a potent gastrointestinal lipase inhibitor against both pancreatic and gastric lipases ( 22 ), we proposed a scientific hypothesis that SPE could be used as a natural food supplement to promote weight control in obese individuals in a similar mechanism of action as orlistat.…”

“…To date, the therapeutic effects of sweet potato tuber or leaf on hyperglycemia in type 2 diabetes mellitus, dyslipidemia, cardiovascular health, and inflammation have been reported ( 6 – 9 ), suggesting that sweet potato products can possibly be utilized for anti-obesity treatment. We found previously that resin glycosides (RG) exhibited potent pancreatic lipase (PL) inhibitory activity and RG is the active compound in the ethanolic extract of I. batatas leaves and tubers ( 10 – 12 ). Inspired by orlistat, which is an anti-obesity drug due to its inhibition effect on gastric and PL, sweet potato extract (SPE) containing RG has the great potential for weight loss in obese individuals.…”

In Vitro Gastrointestinal Digestion of Various Sweet Potato Leaves: Polyphenol Profiles, Bioaccessibility and Bioavailability Elucidation

“…Previous studies demonstrated that SPLPs usually exhibit powerful antioxidant properties and certain antiglycemic activity in mice [4,30]. Figure 3C illustrated a significant increase in DPPH + scavenging activity throughout oral-GI digestion (p < 0.05).…”

“…Many previous studies have reported that SPLs are associated with promising bioactivities, including antioxidant, antidiabetic, antitumor and anti-inflammatory capacity, and protecting hepatic and/or cardiac lesions [3]. SPLs used to be discarded as a by-product in the sweet potato processing industry and only approximately 10% of the annual production is now being consumed as a new type of healthy vegetable in several countries [4]. Obviously, the lack of deep processing products of SPLs still exists [5], and only Toy et al have reported in recent years that they successfully extracted and modified the pectin from SPLs with enhanced biological activities [6].…”