Antidiabetic effect of Cordia morelosana, chemical and pharmacological studies

Abstract

Ethnopharmacological importance: CORDIA MORELOSANA: Standley (Boraginaceae) is commonly used in folk medicine for the treatment of diarrhoea, kidney inflammation, diabetes, lung pain, bronchitis, asthma, hoarseness, cough and fever.

Aim: Current work was conducted to develop a bio-guided isolation of antidiabetic compounds from ethanolic extract of Cordia morelosana (EECm).

Material and methods: The phytochemical bio-guided study was conducted by successive chromatographic techniques, and isolated compounds were characterized by 1D and 2D-NMR experiments. The in vivo antihyperglycemic and antidiabetic activities of EECm (100 mg/kg), and methyl rosmarinate (MR, 50 mg/kg) were determined on normoglycemic and diabetic murine models. Additionally, the in vitro activity was conducted to determine α-glucosidase inhibitory effect, and PPARs, GLUT4 and FATP expression on 3T3-L1 cells by RT-PCR. Acute and sub-chronic toxicological studies for EECm were conducted on rats, following the OECD guidelines (No. 420 and 407).

Results: EECm promotes significant α-glucosidase inhibition (55.6%) at 1 mg/kg respect to the control. Also, EECm (100 mg/kg) showed significant antihyperglycemic effect on oral glucose tolerance test (OGTT), and in non-insulin dependent type 2 diabetes (NIDD) model, had antidiabetic activity (p < 0.001) compared to controls. The bio-guided isolation allowed to obtain four known compounds described as rosmarinic acid (RA), methyl rosmarinate (MR), nicotiflorine and 1-O-methyl-scyllo-inositol. On the other hand, MR showed significant antidiabetic and anthiyperglycemic activities (p < 0.05), and overexpression of PPARγ, PPARα, GLUT-4 and FATP than control. Docking studies were conducted with PPARγ and PPARα, showing interesting binding mode profile on those targets. Finally, EECm displayed a LD₅₀ > 2000 mg/kg and sub-chronic toxicological study reveals no toxic signs in animals tested compared to control.

Conclusion: EECm showed significant antihyperglycemic and antidiabetic actions being RA and MR the main antidiabetic metabolites.

Keywords: Cordia morelosana standley; Diabetes; Methyl rosmarinate; PPARα; PPARγ; α-Glucosidases.