Type 2 diabetes mellitus (T2DM) is a chronic, complex and multifactorial metabolic disorder, which has become a serious global health problem. The side effects of known drugs and the deficiency of long-term safety data, in addition to the already determined adverse effects for the current preclinical drugs against T2DM, have largely called upon the urgent exploration of novel therapeutic and preventative strategies against this disease. The authors highlight the potential approaches for anti-T2DM drug discovery by focusing on: the restoration of pancreatic β-cell mass, the promotion of insulin secretion, the regulation of oxidative stress and endoplasmic reticulum (ER) stress and the modulation of autophagy. T2DM is based on the gradual development of insulin resistance and β-cell dysfunction. Thus, the restoration of β-cell function is considered as one of the promising therapeutic strategies against T2DM. The stress factors, such as oxidative stress, ER stress and autophagy, play potent roles in the regulation of β-cell apoptosis, insulin secretion and sensitivity in the development of T2DM involving complicated cross-talks. Based on multiplex stress-involved regulatory networks, more and more novel potential targets have been discovered and the multi-targeted drug leads are expected to help develop more effective clinical agents for the treatment of T2DM.
Non-alcoholic fatty liver disease (NAFLD) is an increasingly epidemic metabolic disease with complex pathogenesis. Multi-target therapy may be an effective strategy for NAFLD treatment, and traditional Chinese medicine (TCM) characterized by multi-ingredients and multi-targets has unique advantages in long-term clinical practice. Zexie–Baizhu (ZXBZ) decoction is a Chinese classical formula to treat body fluid disorders initially. Although many bioactive monomers from Zexie and Baizhu had been discovered to improve lipid disorders, limited research studies were focused on the aqueous decoction of ZXBZ, the original clinical formulation. In the current study, we identified 94% chemical composition of ZXBZ decoction and first discovered its hepaprotective effect in a gubra-amylin NASH (GAN) diet-induced NAFLD mouse model. Based on metabolomics and transcriptomics analyses, we speculated that lipid and glucose metabolisms might be regulated by ZXBZ decoction, which was further confirmed by improved dyslipidemia and hepatic steatosis in ZXBZ groups. Consistently with cross-omics analysis, we discovered ZXBZ decoction could influence two energy sensors, Sirt1 and AMPK, and subsequently affect related proteins involved in lipid biosynthesis, catabolism, and transport. In conclusion, ZXBZ decoction regulated energy sensors, consequently impeded lipogenesis, and promoted fatty acid oxidation (FAO) to alleviate lipid disorders and protect the liver in NAFLD models, which suggested ZXBZ decoction might be a promising treatment for NAFLD.
Kv2.1 as a voltage-gated potassium (Kv) channel subunit has a pivotal role in the regulation of glucose-stimulated insulin secretion (GSIS) and pancreatic β-cell apoptosis, and is believed to be a promising target for anti-diabetic drug discovery, although the mechanism underlying the Kv2.1-mediated β-cell apoptosis is obscure. Here, the small molecular compound, ethyl 5-(3-ethoxy-4-methoxyphenyl)-2-(4-hydroxy-3-methoxybenzylidene)-7-methyl-3-oxo-2,3-dihydro-5H-[1,3]thiazolo[3,2–a]pyrimidine-6-carboxylate (SP6616) was discovered to be a new Kv2.1 inhibitor. It was effective in both promoting GSIS and protecting β cells from apoptosis. Evaluation of SP6616 on either high-fat diet combined with streptozocin-induced type 2 diabetic mice or db/db mice further verified its efficacy in the amelioration of β-cell dysfunction and glucose homeostasis. SP6616 treatment efficiently increased serum insulin level, restored β-cell mass, decreased fasting blood glucose and glycated hemoglobin levels, and improved oral glucose tolerance. Mechanism study indicated that the promotion of SP6616 on β-cell survival was tightly linked to its regulation against both protein kinases C (PKC)/extracellular-regulated protein kinases 1/2 (Erk1/2) and calmodulin(CaM)/phosphatidylinositol 3-kinase(PI3K)/serine/threonine-specific protein kinase (Akt) signaling pathways. To our knowledge, this may be the first report on the underlying pathway responsible for the Kv2.1-mediated β-cell protection. In addition, our study has also highlighted the potential of SP6616 in the treatment of type 2 diabetes.