The inhibition of α-glycosidase and protein tyrosine phosphatase 1B (PTP1B) activities by ginsenosides from Panax ginseng C.A. Meyer and simultaneous determination by HPLC-ELSD

• 25-OH-PPT, 25-OCH3-PPT, PPT, PT, 25-OH-PPD, 25-OCH3-PPD, PPD and PD are hydrolysis compounds.
• An HPLC-ELSD method was developed to simultaneously determine 8 ginsenosides in different ginseng parts.
• HPLC-ELSD was proven to be a simple, fast, and effective method.
• Eight compounds were tested for their α-glycosidase and PTP1B inhibitory activities.
• 25-OH-PPT exerted stronger inhibitory activity than acarbose and Na3VO4.

Panax ginseng C.A. Meyer is extensively used as a food additive because of its medicinal and nutritional properties. This study investigated the inhibitory activity of eight ginsenosides against α-glycosidase and protein tyrosine phosphatase 1B (PTP1B). Results showed the anti-hyperglycaemic activities of the eight ginsenosides were in the order of 20(R)-dammarane-3β, 6α, 12β, 20, 25-pentol (25-OH-PPT) > 20(R)-25-methoxydammarane-3β, 12β, 20-tetrol (25-OCH3-PPT) > 20(R)-protopanaxatriol (PPT) > 20(S)-panaxatriol (PT) > 20(R)-dammarane-3β, 12β, 20, 25-tetrol (25-OH-PPD) > 20(R)-25-methoxydammarane-3β, 12β, 20-triol (25-OCH3-PPD) > 20(R)-protopanaxadiol (PPD) > 20(S)-panaxadiol (PD), and 25-OH-PPT exerted stronger inhibitory activity than acarbose and Na3VO4. Meanwhile, simultaneous quantitative estimation results of eight ginsenosides suggested good linear regression within test ranges, precision, accuracy. 25-OH-PPT of the stems (leaves), flowers, and fruits contained 2.69, 3.31 and 7.20%, respectively. High performance liquid chromatography-evaporative light-scattering detector (HPLC-ELSD) method was proven to be simple, fast, and effective.