Foods (Oct 2023)

Inhibitory Effects of Saponin-Rich Extracts from <i>Pouteria cambodiana</i> against Digestive Enzymes α-Glucosidase and Pancreatic Lipase

  • Kawisara Sanneur,
  • Noppol Leksawasdi,
  • Nutsuda Sumonsiri,
  • Charin Techapun,
  • Siraphat Taesuwan,
  • Rojarej Nunta,
  • Julaluk Khemacheewakul

DOI
https://doi.org/10.3390/foods12203738
Journal volume & issue
Vol. 12, no. 20
p. 3738

Abstract

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Pouteria cambodiana is a perennial plant that has a wide distribution in tropical regions. It is commonly referred to as ’Nom-nang’ in the northern region of Thailand. The bark of this plant has been used for the purpose of promoting lactation among breastfeeding mothers. Moreover, P. cambodiana bark has a high nutraceutical potential due to the presence of saponins, which are secondary metabolites. The purpose of this study was to determine the optimal conditions for ultrasound-assisted extraction (UAE) of saponins from the bark of P. cambodiana and to assess the in vitro inhibitory activities of saponin-rich extracts. The most effective extraction conditions involved a temperature of 50 °C and a 50% concentration level of ethanol as the solvent, which allowed the extraction of saponin at a concentration of 36.04 mg/g. Saponin-rich extracts and their hydrolysates from P. cambodiana bark were evaluated for their ability to inhibit α-glucosidase and pancreatic lipase. The IC50 values for saponin- and sapogenin-rich extracts inhibiting α-glucosidase were 0.10 and 2.98 mg/mL, respectively. Non-hydrolysed extracts also had a stronger inhibitory effect than acarbose. In the case of pancreatic lipase, only the hydrolysed extracts exhibited inhibitory effects on pancreatic lipase (IC50 of 7.60 mg/mL). Thus, P. cambodiana bark may be an applicable natural resource for preparing ingredients for functional products with inhibitory activity against α-glucosidase and pancreatic lipase. The phenolic contents, saponin contents, and antioxidant activities of the dried extract stored at a low temperature of 25 °C for 2 months showed the best stability, with more than 90% retention.

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