Gamma-linolenic acid ameliorated glycation-induced memory impairment in rats

Context: γ-Linolenic acid (GLA) is an important constituent of anti-ageing supplements.

Objective: The current study investigates the anti-ageing effect of GLA in Sprague-Dawley rats.

Materials and methods: GLA (0.1, 0.2, 0.4, 2, 10, 20 and 24 μM) was initially evaluated for its effect on the formation of advanced glycation end products (AGEs) in vitro. For in vivo assessment (1, 5 or 15 mg/kg), the rat model of accelerated ageing was developed using d-fructose (1000 mg/kg (i.p.) plus 10% in drinking water for 40 days). Morris water maze was used to evaluate impairment in learning and memory. The blood of treated Animals was used to measure glycosylated haemoglobin (HbA1c) levels. The interaction of GLA with active residues of receptor of AGE (RAGE) was analyzed using AutoDock Vina.

Results: Our data showed that GLA inhibited the production of AGEs (IC₅₀ = 1.12 ± 0.05 μM). However, this effect was more significant at lower tested doses. A similar pattern was also observed in in vivo experiments, where the effect of fructose was reversed by GLA only at lowest tested dose of 1 mg/kg. The HbA1c levels also revealed significant reduction at lower doses (1 and 5 mg/kg). The in silico data exhibited promising interaction of GLA with active residues (Try72, Arg77 and Gln67) of RAGE.

Conclusion: The GLA, at lower doses, possesses therapeutic potential against glycation-induced memory decline.

Advanced glycation end products; ageing; learning and memory.