Combined effect of probucol and insulin on cataracts of diabetic rats fed a high cholesterol diet

Probucol mitigates high-fat diet-induced cognitive and social impairments by regulating brain redox and insulin resistance

Probucol has been utilized as a cholesterol-lowering drug with antioxidative properties. However, the impact and fundamental mechanisms of probucol in obesity-related cognitive decline are unclear. In this study, male C57BL/6J mice were allocated to a normal chow diet (NCD) group or a high-fat diet (HFD) group, followed by administration of probucol to half of the mice on the HFD regimen. Subsequently, the mice were subjected to a series of behavioral assessments, alongside the measurement of metabolic and redox parameters. Notably, probucol treatment effectively alleviates cognitive and social impairments induced by HFD in mice, while exhibiting no discernible influence on mood-related behaviors. Notably, the beneficial effects of probucol arise independently of rectifying obesity or restoring systemic glucose and lipid homeostasis, as evidenced by the lack of changes in body weight, serum cholesterol levels, blood glucose, hyperinsulinemia, systemic insulin resistance, and oxidative stress. Instead, probucol could regulate the levels of nitric oxide and superoxide-generating proteins, and it could specifically alleviate HFD-induced hippocampal insulin resistance. These findings shed light on the potential role of probucol in modulating obesity-related cognitive decline and urge reevaluation of the underlying mechanisms by which probucol exerts its beneficial effects.

Therapeutic effect of Keap1-Nrf2-ARE pathway-related drugs on age-related eye diseases through anti-oxidative stress

Age-related eye diseases, including cataract, glaucoma, diabetic retinopathy (DR), and age-related macular degeneration (AMD), are the leading causes of vision loss in the world. Several studies have shown that the occurrence and development of these diseases have an important relationship with oxidative stress in the eye. The Keap1-Nrf2-ARE pathway is a classical pathway that resists oxidative stress and inflammation in the body. This pathway is also active in the development of age-related eye diseases. A variety of drugs have been shown to treat age-related eye diseases through the Keap1-Nrf2-ARE (Kelch-like ECH-Associating protein 1- nuclear factor erythroid 2 related factor 2-antioxidant response element) pathway. This review describes the role of oxidative stress in the development of age-related eye diseases, the function and regulation of the Keap1-Nrf2-ARE pathway, and the therapeutic effects of drugs associated with this pathway on age-related eye diseases.

Influence of aging on gastric ulcer healing activities of the antioxidants alpha-tocopherol and probucol

In the present study, we compared the effects of alpha-tocopherol and probucol, antioxidants, on the healing of acetic acid-induced gastric ulcers in 8-, 48- and 96-week-old rats. The repeated oral administration of alpha-tocopherol (16 mg/kg twice daily) and probucol (1000 mg/kg twice daily) for 14 consecutive days markedly accelerated the gastric ulcer healing in 48- and 96-week-old rats as well as 8-week-old ones. The ulcer healing effects of both drugs were not significantly different among the rats at three different ages. The superoxide dismutase (SOD) activity in the ulcerated region of 8-, 48- and 96-week-old rats was markedly lower than that in the unulcerated region. In contrast, the thiobarbituric acid (TBA)-reactive substance content, an index of lipid peroxidation, in the ulcerated region of rats at three different ages markedly increased, as compared to that in the unulcerated region. The SOD activity tended to decrease with aging, while the TBA-reactive substance content gradually increased. The repeated administration of alpha-tocopherol and probucol accelerated the ulcer healing and inhibited the increase in the TBA-reactive substance content in the ulcerated region. These results suggest that alpha-tocopherol and probucol promote the ulcer healing by their potent antioxidant activities in 48- and 96-week-old rats as well as 8-week-old rats.

Combined effect of probucol and insulin on renal damage in diabetic rats fed a high cholesterol diet

We investigated the effects of long-term treatment with probucol, a hypolipidemic agent with antioxidative action, insulin, or their combination on renal damage in streptozotocin-induced diabetic rats fed a high cholesterol diet. Increases in urinary albumin and lipid peroxide excretions were observed in these diabetic rats, when both urinary parameters were measured at 8 and 15 weeks after streptozotocin administration. Daily treatment with probucol, insulin, or their combination markedly suppressed the increase in the 24 h urinary albumin and lipid peroxide excretions. Furthermore, glycogen degeneration of distal tubules, fatty degeneration of glomerular endothelium, and hypertrophy of glomeruli and mesangium were observed in the kidneys of the diabetic animals, when histopathological evaluation was performed at 4, 8 and 15 weeks (glomerular and mesangial hypertrophy was observed only at 15 weeks). Combined probucol and insulin treatment was the most effective in suppressing these renal histopathological changes. These results indicate that combined treatment with probucol and insulin is useful in preventing the progression of renal damage in diabetic rats. The possible mechanisms for the preventive effect of this combined treatment will be discussed.