Preventive effect of Nigella sativa on M1/M2 ratio, reducing risk of endothelial dysfunction in cigarette smoked Wistars

Background: Smoking is one of the top three causes of cardiovascular disease (CVD). Natural antioxidants including black cumin ( Nigella sativa) may inhibit the pathogenesis of initial process of atherosclerosis. The aim of this study was to determine the effect of black cumin (Nigella sativa) in preventing endothelial dysfunction mainly through macrophage M1/M2 inflammatory response in cigarette smoked male Wistars. Methods: In total, 50 Wistar rats were randomly allocated to five experimental groups: two control groups, namely no intervention (K-) and exposure to smoke of 40 cigarettes each day (K+); and three treatment groups: rats given a dose of 0.3 g (P1), 0.6 g (P2) or 1.2 g (P3) black cumin per kilograms bodyweight/ day, respectively, and exposed to smoke of 40 cigarettes each day. After 28 days of cigarette smoke exposure, macrophage M1/M2 ratio was evaluated by counting total M1 and M2 in ten microscope field of view. Data were analysed by Mann-Whitney test. Results: The M1 / ​​M2 ratio on K (-) was 0.9 7 ± 0.9 8 (<1) which means M2 was dominant, while the M1 / ​​M2 ratio on K (+) was of 4.97 ± 3.42 (> 1) which means M1 dominant. There was no significant difference in the number of M1 count in treatment groups P1, P2, P3 (p value = 0.996; 0.170; 0.884, respectively) when compared with K+. Additionally, P2 group has the lower M1 number with the highest significance value when compared to K+. The number of M1 counts on P1 did not differ significantly when compared to P2 with p = 0.121 and P3 with p = 0.936. Conclusions: In sum, ethanol extract of black cumin prevents endothelial dysfunction by inhibiting increase in macrophages M1 / M2 ratio in rats Wistar exposed to sub-chronic cigarette smoke.