# Activation of the Insulin Receptor by Sarcopoterium spinosum Extract and Identification of Sarcocyanidin A as a Novel Active Compound

## TL;DR

This study identifies a new compound in Sarcopoterium spinosum that lowers blood sugar by activating the insulin receptor.

## Contribution

Discovery of sarcocyanidin A, a novel procyanidin trimer, as an insulin receptor activator from Sarcopoterium spinosum.

## Key findings

- Sarcocyanidin A activates insulin signaling in cell models and reduces blood glucose in mice.
- The compound directly interacts with the insulin receptor, as shown by binding assays.
- The antidiabetic effects of Sarcopoterium spinosum are partially mediated by sarcocyanidin A.

## Abstract

Sarcopoterium
spinosum is a medicinal
plant, presenting glucose-lowering properties. The study aimed to
identify the active components and their mechanisms of action. Bioguided
fractionation was utilized to isolate the active molecules, followed
by NMR and HRESI MS for their identification and structural elucidation.
Binding to the insulin receptor (IR) and activation of the receptor
were measured in vitro. Glucose-lowering effects
were validated in vivo. A novel procyanidin trimer,
named sarcocyanidin A (1, catechin-(4α-8)-epicatechin-(4β-8)-epicatechin),
was identified. Sarcocyanidin A (1) activated insulin
signaling in CHO-IR and L6 myotubes, while the IR inhibitor abolished
this effect. IR autofluorescence and cell-based thermal shift assays
indicate a direct interaction of sarcocyanidin A (1)
with IR. Sarcocyanidin A (1) also activated insulin signaling
and reduced blood glucose in mice. Sarcocyanidin A, a novel procyanidin
trimer, mediates at least part of the antidiabetic properties of SSE,
through activation of IR.