Increased nuclear factor (NF-kβ) and carbonyl stress due to decreased glyoxalase-1 activity (Glo-I) contribute significantly to insulin resistance and vascular complications. Therefore, we aimed to study the impact of the combination of thiamine and niacin on hepatic NF-kβ signaling, metabolic profile, and Glo-I activity in male rats with type-2 diabetes (T2DM). Forty male rats were divided equally into five groups: control, diabetic, diabetic treated with thiamine (180 mg/l in drinking water), niacin (180 mg/l), and a combination of both. The treated groups received the treatments daily in drinking water for two months. T2DM was induced using a combination of nicotinamide and alloxan. Metabolic profile and renal dysfunction parameters were assessed. Additionally, various glycation, oxidative stress, and inflammatory markers were measured. The treated group with both vitamins showed the lowest blood sugar and insulin resistance indices, cardiovascular indices, renal dysfunction parameters, hepatic NF-kβ expression, oxidative stress, inflammatory and glycation markers, and the highest anti-oxidant and anti-glycation markers, β cell activity, and insulin sensitivity. Thiamine exhibited more anti-inflammatory activity than niacin in diabetic rats, while niacin demonstrated stronger anti-oxidant activity (P<0.001). The combined use of vitamins had a more beneficial impact on macro and microvascular complications in diabetes than each alone, attributed to their higher anti-oxidant, anti-inflammatory, and anti-glycation characteristics. The vitamins also had a more corrective effect on glucose-lipid metabolism, insulin sensitivity, and renal function through a stronger lowering effect on hepatic NF-kβ expression.
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