Protective Effects of Chaya against Mitochondrial and Synaptic Toxicities in the Type 2 Diabetes Mouse Model TallyHO

Abstract

The purpose of our study is to determine the protective effects of the chaya leaf against mitochondrial abnormalities and synaptic damage in the Type 2 diabetes (T2D) mouse model, TallyHO (TH). The TH mouse is a naturally occurring polygenic mouse model of diabetes that mimics many characteristics of human Type 2 diabetes. Only male TH mice develop hyperglycemia and moderate obesity. Female mice display moderate obesity but do not manifest overt diabetes. In this study, we evaluated three groups of mice over a period of 11 weeks: (1) the experimental group of TH diabetic mice fed with chaya chow; (2) a diabetic control group of TH diabetic mice fed with regular chow; and (3) a non-diabetic control group of SWR/J mice fed with regular chow. Body mass and fasting blood glucose were assessed weekly. Brain and other peripheral tissues were collected. Using qRT-PCR and immunoblotting analyses, we measured the mRNA abundance and protein levels of mitochondrial biogenesis, mitochondrial dynamics, autophagy/mitophagy, and synaptic genes. Using immunofluorescence analysis, we measured the regional immunoreactivities of mitochondrial and synaptic proteins. Using biochemical methods, we assessed mitochondrial function. We found increased body mass and fasting glucose levels in the TH diabetic mice relative to the non-diabetic control SWRJ mice. In chaya chow-fed TH diabetic mice, we found significantly reduced body mass and fasting glucose levels. Mitochondrial fission genes were increased and fusion, biogenesis, autophagy/mitophagy, and synaptic genes were reduced in the TH mice; however, in the chaya chow-fed TH diabetic mice, mitochondrial fission genes were reduced and fusion, biogenesis, autophagy/mitophagy, and synaptic genes were increased. Mitochondrial function was defective in the diabetic TH mice; however, it was rescued in the chaya chow-fed TH mice. These observations strongly suggest that chaya chow reduces the diabetic properties, mitochondrial abnormalities, and synaptic pathology in diabetic, TH male mice. Our data strongly indicates that chaya can be used as natural supplemental diet for prediabetic and diabetic subjects and individuals with metabolic disorders.