Crocin attenuate Tumor Necrosis Factor-alpha (TNF-α) and interleukin-6 (IL-6) in streptozotocin-induced diabetic rat aorta

Crocus sativus L. aqueous extract reduces atherogenesis, increases atherosclerotic plaque stability and improves glucose control in diabetic atherosclerotic animals

BACKGROUND AND AIMS

We aimed to evaluate a possible atheroprotective effect of saffron aqueous extract (SFE), and its potential anti-inflammatory mechanisms, in apoE knockout (ApoE^-/-) mice.

METHODS

Fifty male, ApoE^-/- mice, fed a high-fat diet (HFD) for 12 weeks, were randomized into 5 groups: (1) baseline group, euthanatized, without intervention, (2) three saffron groups, receiving HFD and 30,60,90 mg/kg/day of SFE, respectively, for four weeks, per os through gavage, after reconstitution in water for injection (WFI), (3) control group (COG), receiving daily HFD and the same volume of WFI (four weeks). After blood sampling and euthanasia, aortic roots were excised and analyzed for gene expression and/or percentage of aortic stenosis, relative content of macrophages, smooth muscle cells (SMCs), connective tissue, tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinases-2,-3,-9 (MMP-2,-3,-9) and their inhibitor (TIMP-2) and IL-6. SFE doses were determined by a pilot serum pharmacokinetic study in C57BL/6J wild-type mice.

RESULTS

SFE did not affect body weight and total cholesterol levels (p > 0.05), while high SFE dose significantly ameliorated glucose and triglycerides profiles compared to other groups (p < 0.05). SFE considerably decreased aortic stenosis in a dose-dependent manner (p < 0.05). Furthermore, increasing SFE doses proportionally reduced macrophages content and increased within plaques content of collagen, elastin, and SMCs, promoting more stable plaque phenotype compared to COG (p < 0.05). Those effects seemed to be associated with a considerable reduction (>30%) in IL-6, TNF-α, MCP-1, MMP-2,-3,-9 (p < 0.05) and MMP-2/TIMP-2 ratio.

CONCLUSIONS

SFE exerted dose-dependent anti-atherosclerotic and plaque-stabilizing effects in Apo-E^-/- mice, probably mediated by a favorable modification of inflammatory mechanisms, which requires further investigation.

Catechin Treatment Ameliorates Diabetes and Its Complications in Streptozotocin-Induced Diabetic Rats

CONTEXT

Diabetes mellitus causes atherosclerosis and lipid abnormalities. Hypolipidemic and antioxidative properties of catechin (CTN) have been reported in several studies.

OBJECTIVE

This study assesses the possible protective effects of CTN against oxidative damage in the diabetic rats.

MATERIALS AND METHODS

The rats were divided into the control, untreated diabetic, and 3 CTN-treated diabetic groups (20, 40, and 80 mg/kg/d, intraperitoneal). The diabetic rats were induced by streptozotocin. Catechin was injected for 4 weeks. At the end of the experimental period, glucose, lipid profile, apoprotein A-I (apo A-I), apoprotein B (apo B), malondialdehyde (MDA) levels, and antioxidant enzymes including glutathione-S-transferase (GST), superoxide dismutase (SOD), and catalase (CAT) activities were determined in serum. Statistical analyses were performed using the InStat 3.0 program.

RESULTS

Streptozotocin caused an elevation of glucose, MDA, triglycerides (TGs), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and apo B with reduction in high-density lipoprotein cholesterol (HDL-C), apo A-I, SOD, CAT, and GST in the serum (P < .05). The findings showed that the significant elevation in the body weight, glucose, MDA, TG, TC, LDL-C, and apo B and reduction in HDL-C, apo A-I, SOD, CAT, and GST were ameliorated in the CTN-treated diabetic groups versus the untreated group, in a dose-dependent manner (P < .05).

CONCLUSION

The present investigation proposes that CTN may ameliorate diabetes and its complications by modification of oxidative stress.