Purification and characterization of aldose reductase from jerboa (Jaculus orientalis) and evaluation of its inhibitory activity by Euphorbia regis-jubae (Webb & Berth) extracts

This study aimed, for the first time, to assess the purification of aldose reductase (AR) in Jaculus orientalis (Dipodidae family) kidney and to evaluate the in vitro aldose reductase inhibitory (ARI) effects of Euphorbia regisjubae (Euphorbiaceae family) aqueous and hydroethanolic extracts. Initial screening assay of the enzymatic AR activity in different jerboa states (euthermic, prehibernating and hibernating) and tissues (brain, brown adipose tissue, liver and kidneys) was assessed. Then, AR has been purified to homogeneity from the kidneys of prehibernating jerboas by a series of chromatographic technics. Furthermore, the in vitro and in silico ARI effects of E. regis-jubae (Webb & Berth) extracts, characterized by hight performance liquid chromatography (HPLC) on the purified enzyme were evaluated. Our results showed that the highest enzyme activity was detected in the kidneys, followed by white adipose tissue and the lungs of pre-hibernating jerboa. The enzyme was purified to homogeneity from jerboa kidneys during prehibernating state with a purification factor of 53.4-fold and a yield of about 6%. AR is monomeric, active in D(+)-glyceraldehyde substrate and in disodium phosphate buffer. The pH and temperature for AR were determined to be 6.5-7.5 and 35 degrees C, respectively. Results of the in vitro ARI activity was strongest with both the hydroethanolic extract (IC50 = 96.45 mu g/mL) and aqueous extract (IC50 = 140 mu g/mL). Molecular docking study indicated that catechin might be the main component in both aqueous and hydroethanolic extracts to inhibited AR. This study provides new evidence on the ARI effect of E. regis-jubae (Webb & Berth), which may be related to its phenolic constituents.

Automated summary

This study assessed the purification of aldose reductase in Jaculus orientalis kidney and evaluated the in vitro aldose reductase inhibitory effects of Euphorbia regisjubae extracts. The enzyme was found to have the highest activity in the kidneys of prehibernating jerboas, and the most effective inhibitory extracts were hydroethanolic and aqueous extracts. Molecular docking study suggested catechin as a potential main component in the extracts for inhibiting aldose reductase.