The synergistic effect of Glucagon-Like Peptide-1 and chamomile oil on differentiation of mesenchymal stem cells into insulin-producing cells

Glucagon-like peptide-1 (GLP-1) has attracted tremendous attention for treatment of diabetes. Likewise, it seems that active ingredients of chamomile oil might have anti-diabetic effects. This work was conducted to investigate the effects of the combination of GLP-1 and chamomile oil on differentiation of mesenchymal stem cells (MSCs) into functional insulin-producing cells (IPCs). In this experimental study, adipose MSCs derived from the adult male New Zealand white rabbits were assigned into four groups: control (without any treatment); GLP-1 (in which cells were treated with 10 nM GLP-1 every other day for 5 days); chamomile oil (in which cells were treated with 100 ug/ml Matricaria chamomilla L. flower oil every other day for 5 days); and GLP-1+ chamomile oil (in which cells were treated with 10 nM GLP-1 and 100 µg/ml M. chamomilla flower oil every other day for 5 days). Characterization of isolated MSCs was performed using flow cytometry, Alizarin red S staining and Oil red O staining. The expressions of genes specific for IPCs were measured using reverse transcriptase-polymerase chain reaction (RT-PCR) assay. Measurement of insulin and the cleaved connecting peptide (C-peptide) in response to different concentrations of glucose, were performed using ELISA kits. Our results demonstrated that isolated cells highly expressed MSC markers and were able to differentiate into osteocytes and adipocytes. Additionally, using GLP-1 in combination with chamomile oil exhibited higher levels of IPCs gene markers including NK homeobox gene 2.2 (NKX-2.2), paired box gene 4 (PAX4), insulin (INS) and pancreatic duodenal homeobox-1 (PDX1) as well as insulin and C-peptide secretion in response to different glucose concentrations compared to GLP-1 or chamomile oil alone (P<0.05). Collectively, these findings establish a substantial foundation for using peptides in combination with natural products to obtain higher efficiency in regenerative medicine and peptide therapy.