The Antioxidant Function of High Density Lipoproteins: A New Paradigm in Atherosclerosis

Curcumin exerts hepatoprotection via overexpression of Paraoxonase-1 and its regulatory genes in rats undergone bile duct ligation

OBJECTIVES

Curcumin is described as an antioxidant, hepato-protective and antifibrotic in liver fibrosis, although its mechanism is still not known. One of the models of the chronic liver disease stemming from oxidative stress and the generation of free radical has been considered to be bile duct ligation (BDL). Paraoxonase 1 (PON1) is a prominent antioxidant enzyme. Therefore, the objective of the present research is to assess the effects of curcumin on upregulation of PON1 in BDL rats.

METHODS

As predicted, the rats have been divided into the four groups of Sham, Sham + Cur (curcumin), BDL and BDL + Cur. We evaluated the efficacy of curcumin (100 mg/kg/day) on protein and gene expression of PON1 and regulatory genes contributed to the gene expression PON1 such as Sp1, PKCα, SREBP-2, AhR, JNK and regulation PON1 activity gene expression of Apo A1.

RESULTS

Curcumin attenuated alterations in liver histology, hepatic enzymes and the mRNA expression of fibrotic markers (p<0.05). In addition, curcumin increased significantly mRNA, protein expression of PON1 and mRNA of the genes that are contributed to the expression of PON1 such as Sp1, PKCα, SREBP-2, AhR, JNK and increased PON1 activity through upregulation of Apo A1 (p<0.05).

CONCLUSIONS

Cirrhosis progression may be inhibited by treatment with curcumin through the increased influence the expression and activity of PON1.

[Molecular mechanisms of the cytoprotector cramizol effect in the experimental dyslipidemia model]

The tested drug cramizol exhibits lipid-lowering and anti-atherogenic effects. Cramizol reduces blood cholesterol and triglycerides. It also increases HDL and reduces the atherogenic index in rats with the chronic dyslipidemia model induced by a hypercholesterol diet. Cramizol is effective as a hypolipidemic agent and its efficiency is comparable with the reference drug, phenofibrate. Cramizol increases expression of the ApoA1 and ApoC2 genes, and also reduces expression of the Scarb1 gene in rats with experimentally induced hyperlipidemia. These mechanisms could be the basis of its hypolipidemic and anti-atherogenic actions.

Beyond LDL-c: The importance of serum oxidized LDL in predicting risk for type 2 diabetes in the middle-aged Asian Indians

AIMS

Oxidized low-density lipoprotein (OxLDL) as the residual lipid plays a crucial role in cardiovascular complications and type 2 diabetes. This study aimed to evaluate the relationship of OxLDL with the conventional risk markers and to find the association of OxLDL with the risk of development of type 2 diabetes in middle-aged (30-50 years) Asian Indians.

MATERIALS AND METHODS

A total of 78 type 2 diabetes patients and 78 age-matched controls were recruited. The serum OxLDL concentration was assessed by enzyme-linked immunosorbent assay (ELISA). Other anthropometric and biochemical measures were also carried out. Multiple logistic regression was used to determine the association of OxLDL and OxLDL to non-oxidized lipoproteins with the occurrence of type 2 diabetes.

RESULTS

OxLDL was significantly higher in type 2 diabetes cases than controls (p < 0.001) even though there was no significant difference in LDL cholesterol (LDL-c) between type 2 diabetes patients and controls. OxLDL correlated significantly with fasting plasma glucose (FPG) and insulin resistance (HOMA-IR). OxLDL did not show any significant correlation with LDL-c. Multiple logistic regression showed a significant association of OxLDL, OxLDL/LDL-c and OxLDL/HDL-c with type 2 diabetes (p < 0.001). LDL-c showed no association with type 2 diabetes. ROC-AUC curve analyses showed OxLDL/HDL-c to have highest discriminatory power for type 2 diabetes (AUC: 0.710 with 95% CI: 0.629-0.791, p < 0.001).

CONCLUSION

Our findings highlight the possibly more attention has to be given to OxLDL for managing lipids and diabetes progression as well as reducing cardiac risk in middle-aged type 2 diabetes patients.

Physicochemical characteristics of Bambara groundnut dietary fibres extracted using wet milling

Abstract The objectives of this study were to extract soluble and insoluble dietary fibres from four Bambara groundnut (BGN) varieties (black-eye, brown-eye, brown and red) using the wet milling method and evaluate their physicochemical properties. The swelling capacities of brown-eye (6.5 g/mL) and black-eye (6.2 g/mL) fibres were higher (p≤0.05) than those of red (6.0 g/mL) and brown (5.5 g/mL) fibres while the water holding capacities of black-eye and brown-eye fibres (2.84 g and 2.83 g water/g sample) were higher (p≤0.05) than those of brown and red fibres. The bulk densities of insoluble dietary fibres (IDFs) and soluble dietary fibres (SDFs) ranged between 0.57 g/mL (red) to 0.67 g/mL (brown-eye) and 0.46 g/mL (brown-eye) to 0.57 g/mL (black-eye), respectively. The oil binding capacities (OBCs) of SDFs ranged between 2.78 g oil/g sample (brown) and 4.03 g oil/g sample (brown-eye) while the OBC of all IDFs did not differ (p>0.05), ranging between 1.52 g oil/g sample (brown) and 1.40 g oil/g sample (brown-eye and black-eye). Black-eye and brown-eye dietary fibres had higher phenolic and total sugar content. The findings of this study indicate the potential of BGN fibres in food systems as fat replacers, emulsion stabilisers, water binders, bulking agents, thickeners and nutritional additives.