Inhibitory Effect on Alpha-glucosidase Activity of Benjakul, Soros Benjakul and Their Plant Components

Abstract

Introduction: Acarbose as α-glucosidase inhibitor reduces blood sugar level and are used to treat diabetes. Thai traditional medicine considered it as an imbalance of body functions. Benjakul (B) and Soros Benjakul (SB) are formulas used for correcting the imbalance. This study reported α-glucosidase inhibition of these formulas.
Method: B and SB comprised 5 plants in different ratios. These were: fruit of Piper retrofractum Linn. (PR), root of Piper sarmentosum Roxb. (PS), stem of Piper interruptum Opiz. (PI), root of Plumbago indica Linn. (PL) and rhizome of Zingiber officinale Rosc. (ZO). Each plant and plant mixtures (B and SB1-SB5) were extracted by three different methods; 1) maceration, 2) decoction, and
3) digestion. The α-glucosidase inhibitory activity was performed and the content of piperine was analysed.
Results: The ethanolic extract and the digested extracts of PI gave IC₅₀ of 132.30 μg/ml and 151.35 μg/ml. Piperine showed IC₅₀ of 45.26 μg/ml. The IC₅₀ of acarbose was 142.77 μg/ml. SB2-SB4 after digestion showed improved activities.
Discussion: Piperine had strongest activity as α-glucosidase inhibitor and the content was highest in PI which explained higher activity of this plant. The digested extracts showed improvement of activities, especially SB2 and SB3.
Conclusion: Piperine and the ethanolic extracted of PI was more active than acarbose as α-glucosidase inhibitor. B and SB exerted moderate to good activity. The SB for diabetics should be the
formula for water (SB2) or wind (SB3) elements.