Effects of the microbial secondary metabolites pyrrolnitrin, phenazine and patulin on INS-1 rat pancreatic β-cells

Abstract

The effects on pancreatic β-cell viability and function of three microbial secondary metabolites pyrrolnitrin, phenazine and patulin were investigated, using the rat clonal pancreatic β-cell line, INS-1. Cells were exposed to 10-fold serial dilutions (range 0-10 μg mL(-1)) of the purified compounds for 2, 24 and 72 h. After 2 h exposure, only patulin (10 μg mL(-1)) was cytotoxic. All compounds showed significant cytotoxicity after 24 h. None of the compounds altered insulin secretion with 2 and 20 mM glucose after 2 h. However, after 24 h treatment, phenazine and pyrrolnitrin (10 and 100 ng mL(-1)) potentiated insulin production and glucose-stimulated insulin secretion, whereas patulin had no effect. Exposure (24 h) to either phenazine (100 ng mL(-1)) or pyrrolnitrin (10 ng mL(-1)) caused similar increases in the Ca(2+) content of INS-1 cells. The outward membrane current was inhibited after 24 h exposure to either phenazine (100 ng mL(-1)) or pyrrolnitrin (10 or 100 ng mL(-1)). This study presents novel data suggesting that high concentrations of pyrrolnitrin and phenazine are cytotoxic to pancreatic β-cells and thus possibly diabetogenic, whereas at lower concentrations these agents are nontoxic and may be insulinotropic. The possible role of such agents in the development of cystic fibrosis-related diabetes is discussed.

Insect pathogenicity in plant-beneficial pseudomonads: phylogenetic distribution and comparative genomics

“…However, some have activity against a broad spectrum of organisms including plants, nematodes, arthropods and even mammalian cells (Maurhofer et al, 1992;Devi and Kothamasi, 2009;Kwak et al, 2011;Neidig et al, 2011;Nisr et al, 2011;Jang et al, 2013) and thus could contribute to Pseudomonas-derived insecticidal activity.…”

Can Goji Berry Extract Attenuate Pancreatic Structural Changes Induced by Patulin Toxin in Male Albino Rats?

“…Previous researches demonstrated that patulin could inhibit RNA and protein synthesis in β cells of islets of Langerhans secondary to decrease the activities of lysosomal enzymes as cathepsin B and acid phosphatase, [30,31] . These cells are more susceptible to endoplasmic reticulum stress because of their high secreting activities and low antioxidant capacities [32] , which is in agreement to our findings.…”

Assessment of the Secondary Metabolite Patulin and Lycium Barbarum Fruit on INS-1 Rat Pancreatic Β-Cells

“…This toxicity of patulin has already been demonstrated against various mammalian cells and has been attributed to its ability to inhibit RNA and protein synthesis. It is also interfere with the activity of many enzymes such as glycogen phosphorylase, glucose-6-phosphatase, hexokinase and aldolase that are considered crucial for cell survival [2]. Lycium barbarum fruit, generally called goji berry or wolfberry, is a well-known traditional Chinese medicine.…”