Venom Peptides, Polyphenols and Alkaloids: Are They the Next Antidiabetics That Will Preserve ß-Cell Mass and Function in Type 2 Diabetes?

Improvement of insulin secretion by pancreatic ß-cells and preservation of their mass are the current challenges that future antidiabetic drugs should meet for achieving efficient and long-term glycemic control in patients with type 2 diabetes (T2D). The successful development of glucagon-like peptide 1 (GLP-1) analogues, derived from the saliva of a lizard from the Helodermatidae family, has provided the proof of concept that antidiabetic drugs directly targeting pancreatic ß-cells can emerge from venomous animals. The literature reporting on the antidiabetic effects of medicinal plants suggests that they contain some promising active substances such as polyphenols and alkaloids, which could be active as insulin secretagogues and ß-cell protectors. In this review, we discuss the potential of several polyphenols, alkaloids and venom peptides from snake, frogs, scorpions and cone snails. These molecules could contribute to the development of new efficient antidiabetic medicines targeting ß-cells, which would tackle the progression of the disease.

Management of adjuvant settings for Stage III melanoma patients in France prior to checkpoint inhibitors: epidemiological data from the RIC-Mel database.

BACKGROUND: Targeted therapies such as BRAF and MEK inhibitors and immunotherapies have been made available to treat melanoma. OBJECTIVES: To provide an overview of the management of the French Stage III melanoma population after complete lymph node resection prior to new adjuvant therapies. MATERIALS AND METHODS: A subgroup data analysis. RESULTS: Data from 1,835 patients were analysed (15.58% Stage IIIA, 39.24% Stage IIIB, 43.92% Stage IIIC and 1.25% Stage IIID). Superficial spreading melanoma was the most frequent (70.98% in Stage IIIA for whom mutation analysis was performed; BRAF mutation was identified in up to 62% Stage IIIA patients). Sentinel lymph node biopsy was performed in 88.46% of Stage IIIA patients, 42.36% of Stage IIIB, 53.97% of Stage IIIC and 34.78% of Stage IIID. Up to 80% of Stage IIIA patients had no adjuvant treatment follow-up. Ulceration (p = 0.004; RR: 2.98; 95% CI: 1.4-6.3) and age at diagnosis (p = 0.0002; RR: 1.04; 95% CI: 1.02-1.06) were significant predictive factors for survival. Adjuvant interferon-α was administered in up to 13.04% of Stage IIID patients. CONCLUSION: Only a small number of Stage III melanoma patients were treated with interferon-α in adjuvant settings. New adjuvant therapies are currently having an effect on clinical practice in France, increasing survival and decreasing cost.

Emerging roles for ß-arrestin-1 in the control of the pancreatic ß-cell function and mass: new therapeutic strategies and consequences for drug screening.

Defective insulin secretion is a feature of type 2 diabetes that results from inadequate compensatory increase in ß-cell mass, decreased ß-cell survival and impaired glucose-dependent insulin release. Pancreatic ß-cell proliferation, survival and secretion are thought to be regulated by signalling pathways linked to G-protein coupled receptors (GPCRs), such as the glucagon-like peptide-1 (GLP-1) and the pituitary adenylate cyclase-activating polypeptide (PACAP) receptors. ß-arrestin-1 serves as a multifunctional adaptor protein that mediates receptor desensitization, receptor internalization, and links GPCRs to downstream pathways such as tyrosine kinase Src, ERK1/2 or Akt/PKB. Importantly, recent studies found that ß-arrestin-1 mediates GLP-1 signalling to insulin secretion, GLP-1 antiapoptotic effect by phosphorylating the proapoptotic protein Bad through ERK1/2 activation, and PACAP potentiation of glucose-induced long-lasting ERK1/2 activation controlling IRS-2 expression. Together, these novel findings reveal an important functional role for ß-arrestin-1 in the regulation of insulin secretion and ß-cell survival by GPCRs.