Therapeutic Mechanisms of Herbal Medicines Against Insulin Resistance: A Review

Abstract

Insulin resistance is a condition in which insulin sensitivity is reduced and the insulin signaling pathway is impaired. Although often expressed as an increase in insulin concentration, the disease is characterized by a decrease in insulin action. This increased workload of the pancreas and the consequent decompensation are not only the main mechanisms for the development of type 2 diabetes (T2D), but also exacerbate the damage of metabolic diseases, including obesity, nonalcoholic fatty liver disease, polycystic ovary syndrome, metabolic syndrome, and others. Many clinical trials have suggested the potential role of herbs in the treatment of insulin resistance, although most of the clinical trials included in this review have certain flaws and bias risks in their methodological design, including the generation of randomization, the concealment of allocation, blinding, and inadequate reporting of sample size estimates. These studies involve not only the single-flavored herbs, but also herbal formulas, extracts, and active ingredients. Numerous of in vitro and in vivo studies have pointed out that the role of herbal medicine in improving insulin resistance is related to interventions in various aspects of the insulin signaling pathway. The targets involved in these studies include insulin receptor substrate, phosphatidylinositol 3-kinase, glucose transporter, AMP-activated protein kinase, glycogen synthase kinase 3, mitogen-activated protein kinases, c-Jun-N-terminal kinase, nuclear factor-kappaB, protein tyrosine phosphatase 1B, nuclear factor-E2-related factor 2, and peroxisome proliferator-activated receptors. Improved insulin sensitivity upon treatment with herbal medicine provides considerable prospects for treating insulin resistance. This article reviews studies of the target mechanisms of herbal treatments for insulin resistance.

C2C12 cell model: its role in understanding of insulin resistance at the molecular level and pharmaceutical development at the preclinical stage

“…[140] C2C12 cells have been utilised to assess the potential of various natural and drug compounds in relieving metabolic conditions. A number of natural and drug compounds have gained attention due to their favourable effects in insulin resistance, [141] anti-ageing, [142][143][144] muscle atrophy [145,146] and hyperlipidaemia. [147,148] For example, previous review showed that natural products, such as Zengye Decoction, Seyoeum, Wu-Mei-Wan, Erchen Decoction, Linguizhugan Decoction, Fenugreek seed, mulberry leaf and Jinlida, could improve insulin resistance in vitro or in vivo.…”

Gegen Qinlian Decoction Coordinately Regulates PPARγ and PPARα to Improve Glucose and Lipid Homeostasis in Diabetic Rats and Insulin Resistance 3T3-L1 Adipocytes

“…GLUTs, PI3K, AMPK, and MAPKs involved in the insulin signaling pathway (Li et al, 2019). Given the clinical significance of GQD in treating T2DM, in-depth study on the molecular mechanism of GQD in regulating glucose and lipid homeostasis to improve IR may provide theoretical basis and treatment guidance.…”

Edgeworthia gardneri (Wall.) Meisn. Water Extract Ameliorates Palmitate Induced Insulin Resistance by Regulating IRS1/GSK3β/FoxO1 Signaling Pathway in Human HepG2 Hepatocytes

“…Natural supplements probably represent an ideal source to explore safe and effective agents for the treatment of IR (Kouzi, 2015;Li et al, 2019). The flower of Edgeworthia gardneri Wall.…”