Glyphosate, Diabetes, Melatonin Deficiency and Autism
Acting as an endocrine disruptor, glyphosate can disrupt insulin signaling, leading to diabetes. Diabetes prevalence is rising in the United States in step with the rise in glyphosate usage on core crops [57]. Oral exposure of albino Wistar rats to glyphosate for 16 weeks was associated with a rise in fasting glucose and insulin, along with a drop in serum testosterone, and an increase in liver production of pro-inflammatory factors, including NF-κB, Il-6, Il-1β, and peroxisome proliferator-activated receptor-γ (PPAR-γ) [101]. Maternal diabetes during pregnancy is associated with increased risks for autism spectrum disorder and cognitive dysfunction in the offspring [102]. High circulating glucose levels interfere with pineal melatonin production, reducing melatonin levels in diabetic rats and type 1 diabetes patients [103]. Type 2 diabetic Goto-Kakizaki rats exhibit impaired melatonin synthesis, with increased inhibitory α-2-adrenoceptors, impaired 5-hydroxytryptophan formation, and reduced pineal gland protein content [104]. Thus, impaired melatonin supply to the fetus during pregnancy due to maternal diabetes could cause autism in the developing fetus via suppression of PIN1 signaling by DAPK1.