Chlamydomonas reinhardtii (red) rich in protoporphyrin Ⅸ exerts anti-diabetic effects in liver tissue

The metabolites derived from microalgae have been attributed with various nutritional and medicinal properties. Therefore, our study aimed to investigate the potential beneficial effects of Chlamydomonas reinhardtii (red), a type of microalgae, in individuals with type 2 diabetes mellitus (T2DM). Mice were fed on high-fat diet and injected with a low dose of streptozotocin to induce T2DM. The diabetic mice were orally treated with either 1% sodium carboxymethylcellulose or Chlamydomonas reinhardtii (red) at doses of 1, 2, or 3 g/kg BW/day for a duration of 4 weeks. The liver sections were subjected to hematoxylin and eosin staining as well as oil red staining for the detection of pathological changes and lipid deposition, respectively. Inflammatory factors in serum were quantified using ELISA kits, while commercial kits were employed to assess oxidative stress-related indicators. Gene expression in liver was analysed by RNA-seq. The results revealed that Chlamydomonas reinhardtii (red) significantly ameliorated fasting blood glucose levels, body weight, triglyceride, and low density lipoprotein cholesterin, while also enhancing oral glucose tolerance and insulin sensitivity. In pathological analysis, Chlamydomonas reinhardtii (red) significantly improved lipid deposition and hepatic tissue damage. Furthermore, Chlamydomonas reinhardtii (red) could obviously decreased the protein expression of G-6-Pase and PEPCK, and regulated the SOCS2/JAK2/STAT5 signaling pathway. Transcriptomic analysis indicated that a total of 972 significantly differentially expressed genes in diabetic mice treated with Chlamydomonas reinhardtii (red). KEGG analyses revealed that lipid and atherosclerosis, MAPK signaling pathway, B cell receptor signaling pathway, TNF signaling pathway, NOD-like receptor signaling pathway, Toll-like receptor signaling pathway, PI3K-Akt signaling pathway were involved in Chlamydomonas reinhardtii (red) modulated process. Therefore, the continuous consumption of Chlamydomonas reinhardtii (red) may have anti-T2DM effects through the inhibition of gluconeogenesis, thus offering a promising alternative for T2DM patient.