Screening and Isolating Major Aldose Reductase Inhibitors from the Seeds of Evening Primrose (Oenothera biennis).

Zhiqiang Wang,Dandan Han,Shigang Shen,Hailiang Nie,Ze Cui,Hongyuan Yan

doi:10.3390/molecules24152709

Abstract

Aldose reductase (AR) is a drug target for therapies to treat complications caused by diabetes mellitus, and the development of effective AR inhibitors (ARIs) of natural origin is considered to be an attractive option for reducing these complications. In this research, the rat lens AR (RLAR) inhibitory activity of evening primrose (Oenothera biennis) seeds was investigated for the first time. In our results, the 50% (v/v) methanol extract of evening primrose seeds exhibits excellent RLAR inhibitory activity (IC50 value of 7.53 μg/mL). Moreover, after enrichment of its bioactive components, the ARIs are more likely to be present in the ethyl acetate fraction of 50% (v/v) methanol extract (EME) of evening primrose seeds, which exhibits superior RLAR inhibitory activity (IC50 value of 3.08 µg/mL). Finally, gallic acid (1), procyanidin B3 (2), catechin (3), and methyl gallate (4) were identified as the major ARIs from the EME by affinity-based ultrafiltration-high-performance liquid chromatography and were isolated by high speed countercurrent chromatography, with gallic acid (11.46 µmol/L) and catechin (14.78 µmol/L) being the more potent inhibitors of the four ARIs identified. The results demonstrated that evening primrose seeds may be a potent ingredient of ARIs.

Highlights

Diabetes mellitus, a disorder characterized by an unnaturally high blood glucose concentration, is a global pandemic that currently affects approximately 415 million adults worldwide [1] and is estimated to affect 552 million adults by 2030 [2]
In this work, the Aldose reductase (AR) inhibitory effect of evening primrose seeds was investigated for the first time, and its major AR inhibitors (ARIs) were enriched and isolated using high speed countercurrent chromatography (HSCCC) guided by affinity-based ultrafiltration-high performance liquid chromatography (HPLC)
Because the activities of the bioactive ingredients in the extracts are influenced by the extraction solvents, n-hexane and 50% (v/v) methanol were evaluated as extraction solvents for their effect on the biological activity of evening primrose seed extracts on the inhibition of rat lens AR (RLAR)

Summary

Introduction

A disorder characterized by an unnaturally high blood glucose concentration, is a global pandemic that currently affects approximately 415 million adults worldwide [1] and is estimated to affect 552 million adults by 2030 [2]. Diabetic complications (both micro- and macrovascular) induced by sustained long-term hyperglycemia are the primary factors in dysfunction and death of diabetic patients [3,4,5]. The development of diabetic complications can be slowed through blood glucose regulation, it cannot be stopped [6,7]. AR becomes the key rate-limiting enzyme of the polyol pathway that catalyzes glucose conversion to sorbitol with the consumption of β-nicotinamide adenine dinucleotide 20 -phosphate reduced tetrasodium salt hydrate (NADPH), resulting in cellular osmolarity and redox imbalances; AR, mediates tissue and vascular damage [10,11].

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Results

Conclusion