Triterpene-enriched fractions from Eucalyptus tereticornis ameliorate metabolic alterations in a mouse model of diet-induced obesity

Etnopharmacological relevance: Eucalyptus tereticornis Sm. (Eu) is a plant species used in traditional medicine to treat diabetes mellitus. Eu leaf extracts have been shown to regulate immuno-metabolic activities that are associated with obesity and insulin resistance. OBE100 and OBE104 are two natural Eu extracts that are rich in pentacyclic triterpenes. The major compounds identified in OBE100 are ursolic acid (UA), oleanolic acid (OA), and ursolic acid lactone (UAL), and the major compounds identified in OBE104 are UA and OA.

Aim of the study: This study aimed to investigate the effects of two extracts from Eu leaves with different triterpene composition in a nutritional animal model of prediabetes.

Methods: A mouse model of diet-induced obesity was used to analyze the effects of the OBE100 and OBE104 treatments on metabolic markers and gene expression in liver and visceral adipose tissue.

Results: Treating the prediabetic mouse model with OBE100 and OBE104 increased glucose tolerance. However, only the Eu extract that contained three triterpenes reduced mouse body weight, hepatic and adipose fat content, and plasma lipid levels. OBE100 treatment also led to decreased hepatic mRNA levels of PPARA, CPT1A, and SERBP1. In visceral adipose tissue, OBE100 treatment reduced expression of PPARA and ACACA and increased UCP1 expression.

Conclusions: These results suggest that developing a new multitargeting bioactive compound from the natural extract from Eu may help combat obesity and diabetes. Treatment with OBE100 had better effects than OBE104 in a diet-induced obesity mouse model, suggesting that the OBE100 extract, which contains three triterpenes, may be beneficial in combating obesity.

Keywords: Natural products; Obesity; Therapeutics; Triterpenes; Type 2 diabetes.