Effects of bakuchiol on the cardiovascular system in rats fed a high-fat diet

Objective: The aim of this study was to demonstrate the effects of bakuchiol (BAK) on oxidant and antioxidation parameters in a high-fat diet-induced atherosclerosis model in rats and to determine its benefits on the atherosclerotic process histopathologically. This study was designed to investigate the protective effects of BAK against atherosclerotic cardiovascular diseases and to determine the potential mechanism of these effects. Materials and Methods: 48 male Wistar rats were included in the study in which atherogenic diet (10% cholesterol and 4% cholic acid) was given as pallet feed consisting of 61.6% of total daily kcal from fat. Randomized rats were divided into 6 groups (Standard diet (SD), SD+Bakuchiol (BAK1, 10M), High fat diet (HFD), HFD+BAK1 (10M), HFD+BAK2 (50 M), SD+BAK2 (50 M). Bakuchiol was dissolved in dimethyl sulfoxide (DMSO) and prepared fresh weekly. It was given by oral gavage at a dose of 10 M and 50 M as standard. The study was planned for 12 weeks. The weights of the rats were measured with a precision balance at weeks 0, 3, 6, 9, 12. At the end of the 6th week, half of the rats were terminated with 4 rats from each group. Euthanasia was performed by drawing excess blood from the abdominal vein. CRP, total cholesterol, LDL, HDL, triglyceride levels were measured by autoanalyzer using commercial kits. Oxidized LDL, TNF alpha, IL-1B, IL-6, IL-10, superoxide dysmutase (SOD), von Willebrand factor (vWF) and nitric oxide (NO) levels reflecting inflammation and oxidative stress were measured by ELISA method using commercial kits. The study was continued with the other rats and the remaining rats were euthanized at the end of the 12th week. The protocol applied in the previous groups was also applied in these groups. In this way, the 6th and 12th week results of the lipid metabolism, antioxidation and antiatherogenic effects of high fat atherogenic diet and high fat diet with bakuchiol on cardiac tissues were compared. Atherosclerotic changes in the carotid arteries, abdominal and iliac arteries were examined histopathologically. Cardiac damage was semiquantitatively determined according to the degree and extent of histopathologic changes. Carotid intima-media thickness, which is directly related to cardiovascular events, coronary artery atherosclerosis, myocardial infarction and stroke risk, was examined by hematoxylin-eosin and von gierson histopathological staining. In our study, the efficacy of bakuchiol was examined immunohistochemically through NF-kB transcription factor. Results: At the end of 12 weeks, no atheroma plaque was observed in the abdominal aorta and iliac arteries in the standard diet groups (group 1, group 2 and group 6), whereas the presence of atheroma plaque was observed in the high fat diet group (group 3) (p=0.007). In addition, a proportional decrease in atheroma plaque formation was observed when 10M and 50 M doses of bakuchiol were administered to the high-fat diet fed rat group. When the abdominal aorta and iliac arteries were examined in terms of endothelial regularity, endothelial regularity was observed in group 1, while endothelial irregularity was observed in group 3 (p=0.031). When 10 M and 50 M doses of bakuchiol were administered to the high fat diet fed rat group, a proportional increase in endothelial regularity was observed. As a result of 6-week feeding with high fat diet (fat content 35%), cholesterol levels were significantly decreased in group 5 (HFD+BAK2) compared to group 3 (HFD), triglyceride levels were higher in group 5 compared to other groups except group 4 (HFD+BAK1), HDL and LDL levels were significantly decreased in group 5 compared to group 3 (p<0.05). At the end of the 12-week diet, it was observed that cholesterol levels increased significantly in the high-fat diet group (group 4) compared to the standard diet group (group 2) in the groups given BAK1, there was no significant difference between the groups in triglyceride levels, HDL levels were significantly higher in group 4 compared to group 3, and there was no significant difference in LDL levels (p > 0.05). In rats fed high-fat diet for 12 weeks, there was no significant difference in serum total cholesterol, triglyceride, LDL, HDL levels compared to rats fed standard rat diet (p > 0.05). There was no difference between the groups in oxidized LDL levels at week 6, but a significant increase was observed in group 3 compared to group 1 at week 12. In the standard diet groups, a significant increase in oxidized-LDL levels was observed in group 2 and group 6 compared to group 1, while a significant decrease was observed in group 4 and group 5 compared to group 3. While there was no significant difference in TNF-α levels between the other groups at week 6, group 2 had significantly higher TNF-α levels than group 1 (p < 0.05). At week 12, group 3 had significantly higher TNF-α levels compared to group 1 and group 4 (p < 0.05). No significant difference was observed in IL-1B levels between the groups at 6 and 12 weeks. At week 6, group 3 had significantly higher vWF levels compared to the other groups (p < 0.05). At week 12, it was observed that group 3 had significantly higher vWF levels compared to the other groups, while vWF levels decreased in group 4 and group 5 (p < 0.05). At the end of week 6, group 2 had significantly higher NOS levels compared to group 1 and group 5 (p < 0.05). At the end of week 12, group 2 had significantly higher NOS levels compared to group 1 (p <0.05). Although it did not reach statistical significance, it was shown that NF-kB activity increased in rats fed a high-fat diet at the end of 12 weeks and NF-kB activity decreased with 10M and 50 M doses of bakuchiol. Conclusion: Bakuchiol showed effects on atherosclerosis by protecting endothelial regularity and inhibiting atheroma plaque formation. Our findings suggest that these effects may be mediated by a decrease in oxidized LDL, IL 10, NF-kB and vWF levels. Additional studies with larger series examining the effects of bakuchiol on the cardiovascular system will be enlightening in this regard. Bakuchiol has caused us to get positive results with the effects of mechanisms that need to be elucidated by more detailed studies at the molecular level. We think that bakuchiol may be an effective treatment modality in the treatment of atherosclerosis. Further preclinical and clinical studies are needed to elucidate the mechanism of action of bakuchiol and to determine the appropriate dose adjustment and method of administration. Keywords: Bakuchiol, atherosclerosis, hyperlipidemia, high fat diet, antiinflammatory