Abstract
Various Croton species have been traditionally used to treat diabetes; however, the antidiabetic
potential and safety of many of these species remain poorly understood. This study
evaluated the chemical composition, antihyperglycemic activity, insulin-sensitizing
effect, and acute oral toxicity of C. ehrenbergii. Dichloromethane, ethyl acetate, n-butanol, and aqueous residue fractions were obtained via liquid–liquid extraction
from the hydroalcoholic extract obtained via maceration of the aerial parts. The primary
compounds isolated from the fractions using column chromatography and identified by
1D nuclear magnetic resonance spectroscopy were 7,4′-di-O-methylnaringenin, β-sitosterol, tiliroside, rutin, nicotiflorin, isoquercetin, and l-quebrachitol. The in vivo antihyperglycemic activity of these compounds was assessed using oral sucrose and
glucose tolerance tests, and the most active fractions were evaluated ex
vivo to explore the mechanisms of action. The extract, fractions, and compounds were tested
in vitro for their ability to inhibit α-glucosidase and protein tyrosine phosphatase 1B (PTP1B) as well as for their agonistic
activity on PPAR-γ. Tiliroside and nicotiflorin moderately inhibited PTP1B and α-glucosidase; whereas, l-quebrachitol acted as a PPAR-γ agonist. Acute oral toxicity studies indicated that the extract was safe at the tested
dose. These results provide the first scientific evidence of the antihyperglycemic
properties and preliminary safety of C. ehrenbergii.
Keywords
Euphorbiaceae -
Croton
-
Croton ehrenbergii
- 7,4′-di-
O-methylnaringenin - tiliroside -
L-quebrachitol
