Probiotic treatment with Kefir reduces vascular oxidative stress while suppressing COX2 mediated relaxation in intestinal arteries of an animal model of menopause

Functional foods such as probiotics are known to have benefits in various diseases including metabolic disorders and cardiovascular disease (CVD). In women, CVD has been shown to be linked with their gut microbiota and hormones. Here, we have evaluated the effects of chronic Kefir, a fermented milk beverage in Russia, Central Asia, Middle East and Eastern Europe, on mesenteric artery, using an animal model of menopause focusing on the superoxide anion and COX2 pathways. Two-month-old female Wistar rats were ovariectomized and treated by gavage with Kefir (5 % w/v, 3 mL/kg/day) or milk (Control) during two months. After this period, third-order mesenteric artery segments were isolated and mounted in a myograph system for evaluation of concentration-response curves to acetylcholine. We performed western blot analyses and measured oxidative stress through dihydroethidium (DHE) staining. Kefir reduced vascular oxidative stress, despite not changing SOD2 levels. COX2 levels were not changed by kefir, despite an apparent tendency towards reduction. However, in the functional experiments, under incubation with a COX2 inhibitor, a suppression of this pathway was observed in the kefir group, which suggests an interaction between inflammatory pathways and oxidative stress in this model. The effect of acute incubation with a superoxide anion scavenger on vascular responsiveness was equal in both groups. Kefir reduces vascular oxidative stress levels while suppressing COX2-mediated relaxation in mesenteric vessels in an animal model of menopause; which appears to involve an interplay between these two factors.