Effects of Periploca chevalieri Browicz on Postprandial Glycemia and Carbohydrate-Hydrolyzing Enzymes

Abstract

Background/Objectives:Periploca chevalieri Browicz (Apocynaceae), an endemic species of the Cabo Verde archipelago, is commonly used in traditional medicine for the treatment of diabetes. The aim of this study was to characterize the chemical profiles of the aqueous and hydroethanolic (70%) extracts of the P. chevalieri dried aerial parts (PcAE and PcEE) and evaluate their potential to modulate postprandial glycemia and inhibit key carbohydrate-hydrolyzing enzymes. Methods: The chemical characterization was performed by LC/UV-DAD-ESI/MS/MS. An in vivo evaluation of postprandial glycemia modulation was conducted on healthy CD1 mice submitted to an oral sucrose tolerance test. In vitro enzymatic inhibition was performed for the α-amylase, α-glucosidase, and DPP4 enzymes. Additionally, antioxidant and antiglycation activities were also assessed. Results: Phenolic acid derivatives, flavanols, proanthocyanidins, and flavonols were the major classes of secondary metabolites identified. PcEE at 170 mg/kg of body weight significantly (p < 0.05) reduced the postprandial glycemia peak in CD1 mice submitted to sucrose overload. Regarding the enzymatic inhibition, both extracts showed concentration-dependent inhibitory potential against the α-amylase, α-glucosidase, and DPP4 enzymes. Both extracts inhibited α-glucosidase more effectively than acarbose. Conclusions: The obtained results supports the traditional use of P. chevalieri and suggest the potential for further pharmacological investigation.

Keywords: DPP4; Periploca chevalieri; antiglycation; diabetes; herbal medicine; α-amylase; α-glucosidase.

Figure 1

LC/UV-DAD maxplot chromatogram profile and UV spectra with retention times of the Periploca chevalieri aqueous extract (PcAE) and Periploca chevalieri hydroethanolic extract (PcEE).

Figure 2

Main marker secondary metabolite structures from P. chevalieri aerial part extracts.

Figure 3

Blood glucose curves for the oral sucrose tolerance test (OSTT) in CD-1 mice treated with the Periploca chevalieri hydroethanolic extract (PcEE) or acarbose compared to the normoglycemic and hyperglycemic control groups. Doses: PcEE-D1, 40 mg/kg bw; PcEE-D2, 170 mg/kg bw; PcEE-D3, 300 mg/kg bw; and acarbose, 50 mg/kg bw. The blood samples were taken at 0, 30, 60, 90, and 120 min after the administration of sucrose (3 g/kg) by gavage. The data are presented as the means ± SEs (n = 6–8). Significance levels among different groups at p ≤ 0.05 (* p < 0.05 vs. control (hyperglycemic); ^# p < 0.01 vs. control (hyperglycemic); and ^δ p < 0.0001 vs. control (hyperglycemic).

Figure 4

Lipid profile. Evaluation of mice gavaged with three different doses of the P. chevalieri aerial part extracts and acarbose to determine the levels of (a) cholesterol, (b) HDL, (c) LDL, (d) VLDL, (e) triglycerides, and (f) total lipids and a comparison with the normoglycemic and hyperglycemic control groups. Significance level among different groups at p ≤ 0.05.