Effect of individual and combined supplementation of phytoene, phytofluene, and lycopene against nicotine-induced pancreatic islet cell dysfunction

To understand the capability of carotenoids phytoene, phytofluene, and lycopene supplementation individually and in combination to counter the effect of nicotine-induced oxidative stress-mediated pancreatic islet dysfunctioning. Thirty male Wistar albino rats were divided into six groups: Group A, control; Group B, treated with intraperitoneal injection of nicotine (3 mg/kg bw); Group C, received nicotine intraperitoneally (3 mg/kg bw) and supplemented with phytoene orally (0.19 mg/kg bw); Group D, treated with nicotine intraperitoneally (3 mg/kg bw) and supplemented with phytofluene orally (0.1 mg/kg bw); Group E, treated with nicotine intraperitoneally (3 mg/kg bw) and supplemented with lycopene orally (10 mg/kg bw); and Group F, treated with nicotine intraperitoneally (3 mg/kg bw) and supplemented with a combined dose of phytoene, phytofluene, and lycopene (0.19 mg/kg + 0.1 mg/kg + 10 mg/kg bw). Then sacrificed on 21st day, pancreatic islet cells were isolated and ROS generation was estimated. Likewise, histology and biochemical assays of oxidative and antioxidative stress parameters, and pro-inflammatory cytokines levels were measured by ELISA. Phytoene, phytofluene, and lycopene individually and in combination decreased the nicotine-induced changes in fasting blood glucose, oral glucose tolerance test, and glycated hemoglobin levels. They also provided protection against the oxidative injury, increase in ROS generation and increase in the pro-inflammatory cytokines, both of which are known to be a major step in nicotine-induced islet injury and impairment of glucose homeostasis. Furthermore, it is very much interesting to note that combined supplementation showed higher degree of protection than the individual supplementation. This study has presented experimental evidences that phytoene, phytofluene, and lycopene supplementation individually provides protection against the nicotine-mediated islet impairment. The degree of protection was further enhanced upon the combined supplementation. Thus, these results suggest that the combined supplementation of phytoene, phytofluene, and lycopene may evolve as a probable approach to blunt the effect of nicotine-induced impairment of pancreatic islets.