The synergistic effect of antiglycating agents (MB-92) on inhibition of protein glycation, misfolding and diabetic complications in diabetic-atherosclerotic rat

Co-administration of "L-Lysine, Vitamin C, and Zinc" increased the antioxidant activity, decreased insulin resistance, and improved lipid profile in streptozotocin-induced diabetic rats

PURPOSE

We previously showed the beneficial effect of L-Lysine (Lys), a chemical chaperone, on reducing diabetic complications in diabetic rats and type 2 diabetic patients. Herein, we evaluated the effect of Lys co-administration with Vitamin C and Zinc (Lys+VC+Zn), in diabetic rats.

METHODS

The streptozotocin (50 mg/Kg) was injected into male adult Wistar rats to induce diabetes. Then, different groups of normal and diabetic rats were treated with Lys and Lys+VC+Zn for five months. So, there were 0.1 % Lys in the drinking water of both groups. The control groups received water alone. During the experiment, the body weight, and various parameters were determined in the blood, serum/plasma, and urine of the rats.

RESULTS

The determination of biochemical indexes confirmed diabetes induction and its complications in rats. Treatment with either Lys or Lys+VC+Zn resulted in reduced blood glucose and protein glycation (decreasing AGEs and HbA1c), increased insulin secretion, alleviated insulin resistance and HOMA-IR, improved lipid profile and HDL functionality (LCAT and PON1), enhanced antioxidant status (FRAP and AOPP), improved kidney function (decreased microalbuminuria, serum urea, and creatinine), and increased chaperone capacity (HSP70). Lys+VC+Zn showed better effects on these parameters than Lys alone.

CONCLUSIONS

The results of this study indicated that co-administration of Lys, a chemical chaperone, with two antioxidants (VC and Zn) potentiates its antidiabetic effects and prevent diabetic complications in rat model of diabetes.

Crocetin ameliorative effect on diabetic nephropathy in rats through a decrease in transforming growth factor-β and an increase in glyoxalase-I activity

BACKGROUND & AIMS

Glycation, oxidative stress, and inflammation due to the elevation of transforming growth factor-β1 (TGF-β1) participate in diabetic nephropathy (DN). Thus, we investigated for the first time the effect of crocetin (Crt) on the renal histopathological parameters, TGF-β1 and glycation, oxidative stress, as well as inflammatory markers in the DN rat model.

METHODS

Forty male Wistar rats were randomly divided into 4 equal groups: normal (N), N + Crt, DN, and DN + Crt. DN was induced in rats with a combination of nephrectomy and streptozotocin. Treated groups received 100 mg/kg of Crt via intraperitoneal injection monthly for 3 months. Different glycation (glycated albumin, glycated LDL, Methylglyoxal, and pentosidine), oxidative stress (advanced oxidation protein products, malondialdehyde, glutathione, and paraoxonase-I (PON-1)), and inflammatory markers (tumor necrosis factor-α, myeloperoxidase, and TGF-β1), blood glucose, insulin, lipid profile, creatinine in the serum, and proteinuria, as well as the glyoxalase-1 (GLO-1) activity, was determined.

RESULTS

Crt decreased renal biochemical (Cre and PU) and histopathological (glomerulosclerosis) renal dysfunction parameters, diverse glycation, oxidative stress, and inflammatory markers in the DN rats. Furthermore, the treatment corrected glycemia, insulin resistance, and dyslipidemia as well as induced the activities of GLO-1 and PON-1. Over and above, the treatment decreased TGF-β1 in their serum (p > 0.001).

CONCLUSIONS

Crocetin improved DN owing to an advantageous effect on metabolic profile. Further, the treatment with a reducing effect on TGF-β1, oxidative stress, glycation, and inflammation markers along with an increase in Glo-1 activity showed multiple protective effects on kidney tissue.

Inhibition of notch signalling and mesangial expansion by combined glucagon like peptide-1 agonist and crocin therapy in animal model of diabetic nephropathy

Diabetic nephropathy (DN) is one of the devastating complications in diabetes mellitus (DM). Glucagon-like peptide-1 (GLP-1) is one of the incretins secreted from L cells in the intestine. Crocin (a carotenoid component of saffron) has antioxidants properties. We investigated the renal effects of Exendin-4 as a GLP-1 agonist and Crocin in DN.Thirty male rats were divided into five groups: control, type II DM, type II DM + Exendin-4, type II DM + Crocin ‏ and type II DM + Exendine-4 + Crocin. At the end of the experimental period, systolic and diastolic blood pressures were measured, and GFR was calculated. Blood and urine samples were collected for biochemical analysis. Tissue samples were collected from the kidney for histological examination and biochemical measurements of protein expression.Treatment with GLP-1 agonist or Crocin caused a significant improvement in renal function. Better results were achieved with simultaneous administration of both drugs with inhibition of notch signalling pathway and the related proteins.

1,8 cineole protects type 2 diabetic rats against diabetic nephropathy via inducing the activity of glyoxalase-I and lowering the level of transforming growth factor-1β

Purpose

Diabetes leading to the production and circulation of glycation products along with the reduction of the activity of glyoxalase-I (GLO-I) contribute to diabetic nephropathy. Therefore, we studied the effect of 1,8 cineole (Cin) on the formation of diverse glycation products and the activity of GLO-I as well as renal histopathological alterations in the type-2 diabetic rat.

Methods

Type 2 diabetes was induced in rats with a combination of streptozotocin and nicotinamide (55 + 200 mg/kg). Two groups of rats, normal and diabetic, were treated intragastrically with Cin (200 mg/kg) once daily for 2 months. Fasting blood sugar, insulin resistance index, lipid profile, the activity of GLO-I, glycation products (Glycated albumin, Glycated LDL, Methylglyoxal, and advanced glycation end products), and oxidative stress (Advanced oxidation protein products, malondialdehyde, oxidized LDL, and reduced glutathione), inflammatory markers (Tumor necrosis factor-α and Transforming growth factor-1β), creatinine in the serum (Cre), and proteinuria (PU) in the urine of all rats was determined as well as renal histopathological alterations were investigated.

Results

Cin reduced biochemical (Cre and PU) and histopathological (glomerulosclerosis) indicators of renal dysfunction in the diabetic rat compared to untreated diabetic rats. Moreover, the treatment decreased different glycation, oxidative stress, and pro-inflammatory markers (p < 0.001). Further, Cin had an advantageous effect on glucose and lipid metabolism.

Conclusions

Cin ameliorated diabetic nephropathy via reduction of TGF-1β following to decrease the formation of different glycation products, oxidative stress, and inflammatory process with the induction of the activity of glyoxalase-I in type 2 diabetic rats.

Crocetin: A Systematic Review

Crocetin is an aglycone of crocin naturally occurring in saffron and produced in biological systems by hydrolysis of crocin as a bioactive metabolite. It is known to exist in several medicinal plants, the desiccative ripe fruit of the cape jasmine belonging to the Rubiaceae family, and stigmas of the saffron plant of the Iridaceae family. According to modern pharmacological investigations, crocetin possesses cardioprotective, hepatoprotective, neuroprotective, antidepressant, antiviral, anticancer, atherosclerotic, antidiabetic, and memory-enhancing properties. Although poor bioavailability hinders therapeutic applications, derivatization and formulation preparation technologies have broadened the application prospects for crocetin. To promote the research and development of crocetin, we summarized the distribution, preparation and production, total synthesis and derivatization technology, pharmacological activity, pharmacokinetics, drug safety, drug formulations, and preparation of crocetin.

Interactions of epicatechin and cysteine with certain other dicarbonyl scavengers during their reaction with methylglyoxal under simulated physiological conditions

This study aimed at investigating the effects of interactions between dietary dicarbonyl scavengers coexisting in human plasma on the overall methylglyoxal scavenging potential. Apart from being the most effective dicarbonyl scavengers, epicatechin or cysteine, which can be easily oxidized by other compounds, was reacted with methylglyoxal in the presence of certain other dicarbonyl scavengers under simulated physiological conditions (pH 7.4, 37 °C). Methylglyoxal was monitored kinetically in the presence of the individual scavengers or in their combinations with epicatechin or cysteine. The observed and estimated reaction rate constants were calculated for each combination. As the observed rate constant for the reaction between cysteine and epicatechin was found to be significantly greater (p < 0.05) than the estimated rate constant, the results suggest synergism occurred in this combination. Epicatechin was found to interact antagonistically with scavengers that stimulate its oxidation such as creatine, quercetin, and gallic acid during methylglyoxal scavenging.

Crocetin Exerts Its Anti-inflammatory Property in LPS-Induced RAW264.7 Cells Potentially via Modulation on the Crosstalk between MEK1/JNK/NF-κB/iNOS Pathway and Nrf2/HO-1 Pathway

Crocetin is a main bioactive component with a carotenoid skeleton in Gardenia jasminoides, a typical traditional Chinese medicine with a long history in Southeast Asia. Crocetin is being commonly consumed as spices, dyes, and food colorants. Recent pharmacological studies had implied that crocetin may possess potent anti-inflammatory properties; however, the underlying molecular mechanism is not fully elucidated. In the present study, the regulatory effect of crocetin on redox balance was systematically investigated in lipopolysaccharide- (LPS-) stimulated RAW264.7 cells. The results showed that crocetin dose-dependently inhibited LPS-induced nitric oxide production and inducible nitric oxide synthase (iNOS) expression in RAW264.7 cells. Molecular data revealed that crocetin exerted its anti-inflammatory property by inhibiting the MEK1/JNK/NF-κB/iNOS pathway and activating the Nrf2/HO-1 pathway. The shRNA-knockdown (KD) of MEK1 and ERK1 confirmed that the activation of MEK1 and inhibition of JNK mediated the anti-inflammatory effect of crocetin. Moreover, the pull-down assay and computational molecule docking showed that crocetin could directly bind to MEK1 and JNK1/2. It is noticed that both KD and knockout (KO) of HO-1 gene blocked this action. More detailed data have shown that HO-1-KO blocked the inhibition of p-IκB-α by crocetin. These data indicated that crocetin exerted its anti-inflammatory property via modulating the crosstalk between the MEK1/JNK/NF-κB/iNOS pathway and the Nrf2/HO-1 pathway, highlighting HO-1 as a major player. Therefore, the present study reveals that crocetin can act as a potential candidate for redox-balancing modulation in charge of its anti-inflammatory and chemopreventive effect, which strengthens its potency in the subsequent clinic application in the near future.

Preventive Effect of Eucalyptol on the Formation of Aorta Lesions in the Diabetic-Atherosclerotic Rat

Background:

Glycation, inflammation, and oxidative stress are the cardinal motivators of diabetes vascular complications. Here, we studied the effect of eucalyptol (EUC) on the formation of atheromatous lesions, glycation, oxidative stress, and inflammatory markers as well as insulin resistance, lipid profile, and activity of glyoxalase-1 (GLO-I) in the atherosclerotic rat model.

Methods:

Diabetic-atherosclerosis induced in rats with a combination of streptozotocin and atherogenic diet. Two groups of rats, normal and diabetic-atherosclerotic, were treated intragastrically with EUC (200 mg/kg) once daily for 3 months. Fasting blood sugar (FBS), insulin, insulin resistance index, lipid profile, the activity of GLO-I, low-density lipoprotein (LDL) glycation and oxidation markers, inflammatory markers, creatinine in the serum, and proteinuria in the urine of all rats were determined.

Results:

EUC inhibited the formation of any atheromatous lesions in atherosclerotic rats. Further, EUC displayed the lowering effect on glycemia, insulin resistance, LDL glycation, and oxidation products, and tumor necrosis factor (TNF)-α as well as it exhibited the improving effect on lipid profile, the activity of GLO-I, and renal function in the diabetic rat (P < 0.001).

Conclusions:

EUC prevented the formation of the atheromatous lesions and improved renal function in the atherosclerotic rat model due to a reduction of glycation, oxidative stress, and inflammatory mediators.

Advanced glycation end-products (AGE) trapping agents: Design and synthesis of nature inspired indeno[2,1-c]pyridinones

Advanced glycation end products (AGEs) are implicated to be the key players in most of the diabetic complications. The AGE's interfere with the proteins heterogeneously, thereby rendering denaturation and the consequent loss of function and accumulation. Thus, a novel natural product inspired indeno[2,1-c]pyridinone (4a-4ad) molecular templates with AGE's trapping potential was designed through scaffold hopping approach and synthesized via facile two-step synthetic route. Amongst the tested indeno[2,1-c]pyridinone hybrids, 4i, 4x and 4aa exhibited excellent efficiency in trapping the AGE's. The percentage of antiglycation is measured by the analytical model system, i.e. via MG trapping capacity; here the compounds 4i, 4x and 4aa with 50.03%, 69.58%, and 93.37% respectively has displayed promising efficiency. In particular, 4aa demonstrated better activity than the positive control aminoguanidine (79.82%). The in-vitro toxicity of compounds was tested on L6 rat skeletal muscle cell lines revealed that none of the compounds showed any significant toxicity at concentrations up to 1000 μM.

Thiamine pyrophosphate improved vascular complications of diabetes in rats with type 2 diabetes by reducing glycation, oxidative stress, and inflammation markers

Background: Thiamine deficiency contributes to hyperglycemia and diabetes complications. Thus, in this study, the effect of thiamine pyrophosphate (TPP) on the in vivo and in vitro formation of glycation, oxidative stress, and inflammatory markers (the main contributors of vascular diabetes complications) was examined in type 2 diabetes rat model.

Methods: Type 2 diabetes was induced in rats with a combination of streptozotocin and nicotinamide (55+200 mg/kg). Two groups of rats, healthy and diabetic, were treated with 0.1% TPP in drinking water daily for 3 months and the 2 others received water only. The glucose, insulin, early to end glycation products, the activity of glyoxalase system, lipid profile, LDL oxidation markers, inflammatory markers, creatinine in the serum, and proteinuria in the urine of all rats were determined. Moreover, albumin and LDL were incubated with glucose in the presence and absence of TPP, and the samples were investigated for glycation and oxidation products. Different variables in all 4 groups were compared with multiple analysis of variance (MANOVA-Tukey) test using SPSS version 16. Significance level was set at p<0.05.

Results: TPP decreased the formation of diverse glycation and oxidation products in both in vivo (glycated LDL= 144.50±3.48 and oxidized LDL= 54.08±2.67 μmol/l) and in vitro (glycated LDL= 107.00±2.82 and oxidized LDL= 50.83±1.22 μmol/l). In addition, the vitamin reduced fasting blood sugar (9.23±0.29), insulin resistance (9.10±0.50), tumor necrosis factor-α (285.43±15.97), interleukin-6 (257.65±13.06), and improved the lipid profile, the activity of Glo system (Glo-I= 31.65±1.06 and Glo-II= 27.01±0.90 U/mL) and renal function in the diabetic rat (p<0.001).

Conclusion: TPP decreased the major risk factors for diabetic complications and corrected the alternations of glucose and lipid metabolism in type 2 diabetic rats; thus, it is recommended for diabetes treatment.

Effects of crocin and saffron aqueous extract on gene expression of SIRT1, AMPK, LOX1, NF-κB, and MCP-1 in patients with coronary artery disease: A randomized placebo-controlled clinical trial

This trial evaluated the potential impacts of saffron aqueous extract (SAE) and its main carotenoid on some of the atherosclerosis-related gene expression and serum levels of oxidized low-density cholesterol (ox-LDL) and Monocyte chemoattractant protein 1 (MCP-1) in patients with coronary artery disease (CAD). Participants of this randomized controlled trial included 84 CAD patients who categorized into three groups: Group 1 received crocin (30 mg/day), Group 2 SAE (30 mg/day), and Group 3 placebo for 8 weeks. Gene expression of Sirtuin 1 (SIRT1), 5'-adenosine monophosphate-activated protein kinase (AMPK), Lectin-like oxidized LDL receptor 1 (LOX1), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), and MCP-1 in peripheral blood mononuclear cells assessed by real-time PCR. Furthermore, serum ox-LDL and MCP-1 levels measured at the beginning and end of the intervention. Compared with the placebo group, gene expression of SIRT1 and AMPK increased significantly in the crocin group (p = .001), and the expression of LOX1 and NF-κB decreased significantly (p = .016 and .004, respectively). Serum ox-LDL levels decreased significantly in the crocin group after the intervention (p = .002) while MCP-1 levels decreased both in crocin and SAE groups (p = .001). Crocin may have beneficial effects on CAD patients by increasing the gene expression of SIRT1 and AMPK and decreasing the expression of LOX1 and NF-κB.

The effect of crocetin supplementation on markers of atherogenic risk in patients with coronary artery disease: a pilot, randomized, double-blind, placebo-controlled clinical trial

BACKGROUND AND PURPOSE

Molecular mechanisms of atherogenesis are considered to be emerging therapeutic targets for atherosclerosis prevention. Cell and animal studies have shown that crocetin can decelerate atherogenesis. However, the anti-atherogenic properties of crocetin in humans are still ambiguous.

METHODS AND RESULTS

Fifty clinically diagnosed CAD patients were randomly divided into two parallel groups, crocetin and placebo, who received one capsule of crocetin (10 mg) and placebo per day, respectively, for two months. Serum circulating homocysteine (Hcy) [-1.09 (-1.64 to -0.54) μM, P = 0.001], heart-type fatty acid binding protein (h-FABP) [-2.07 (-2.72 to -1.43) ng mL^-1, P = 0.001], intercellular adhesion molecule 1 [-14.92 (-21.92 to -7.92) ng mL^-1, P = 0.001], vascular cell adhesion molecule 1 [-18.61 (-29.73 to -7.49) ng mL^-1, P = 0.002], and monocyte chemoattractant protein 1 [-4.67 (-6.50 to -2.83) pg mL^-1, P = 0.001] decreased significantly after the trial in the crocetin group, while high-density lipoprotein (HDL) significantly increased [+4.21 (0.68 to 7.73) mg mL^-1, P = 0.021]. Also, systolic [-0.21 (-0.32 to -0.10) mmHg, P = 0.001] and diastolic [-0.20 (-0.34 to -0.07) mmHg, P = 0.004] blood pressures decreased significantly in the crocetin group. Nevertheless, clinically significant percentage changes were only observed in Hcy (-15.25 ± 3.15, μM), HDL (-10.70 ± 5.06, mg dL^-1), and h-FABP (-21.10 ± 3.09, ng mL^-1) in the crocetin group. Furthermore, the relative increase in the gene expressions of sirtuin1 and AMP-activated protein kinase and a decrease in the lectin-type oxidized LDL receptor 1 and nuclear factor-kappa B expression in isolated peripheral blood mononuclear cells in the crocetin group were significant at the end of the trial in comparison with the placebo.

CONCLUSION

As the first human study, we showed the ability of crocetin to alter the expression of atherogenic genes and endothelial cell adhesion molecules in CAD patients. It appears that crocetin could be considered as a promising anti-atherogenic candidate for future studies.

A comprehensive review on biological activities and toxicology of crocetin

Natural products with high pharmacological potential and low toxicity have been considered as the novel therapeutic agents. Crocetin is an active constituent of saffron (Crocus sativus L.) stigma, which in its free-acid form is insoluble in water and most organic solvents. Crocetin exhibits various health-promoting properties including anti-tumor, neuroprotective effects, anti-diabetics, anti-inflammatory, anti-hyperlipidemia, etc. These therapeutic effects can be achieved with different mechanisms such as improvement of oxygenation in hypoxic tissues, antioxidant effects, inhibition of pro-inflammatory mediators, anti-proliferative activity and stimulation of apoptosis in cancer cells. It is also worth considering that crocetin could be tolerated without major toxicity at therapeutic dosage in experimental models. In the present review, we discuss the biosynthesis, pharmacokinetic properties of crocetin and provide a comprehensive study on the biological activities and toxicity along with the mechanism of actions and clinical trials data of crocetin.

Prevention of α-crystallin glycation and aggregation using l-lysine results in the inhibition of in vitro catalase heat-induced-aggregation and suppression of cataract formation in the diabetic rat

The principle role of α-crystallin is chaperoning activity that protect s other proteins against different stresses. High glucose concentration induces the osmotic stress and results in biomacromolecules glycation, which is subsequently cause their conformational and functional changes. Here, the roles of l-lysine (Lys) on the prevention of α-crystallin glycation in both in vitro and in vivo conditions are investigated. The catalase (CAT) activity was considered as a marker of α-crystallin functionality in both conditions. Streptozotocin-induced diabetic rats were treated with 0.1% of the Lys in drinking water. The purified α-crystallin was also incubated with glucose, in the presence or absence of the Lys and its structure-function was compared. The results showed that the visual cataract score was significantly lower in the diabetic rats treated with Lys. After Lys treatment, CAT, superoxide dismutase, aldose reductase and other biochemical parameters in the lens and serum of the diabetic rats returned to the normal value. Formation of the advanced glycation endproducts (AGEs), protein cross-linking, and the hydrophobicity of α-crystallin were changed due to glycation, but they were reversed by Lys treatment. The glycated α-crystallin lost its chaperone activity against heat denatured-CAT, but in the presence of Lys, it preserved its activity and prevented CAT aggregation. In conclusion, Lys treatment significantly inhibited the progression of diabetic cataract in rats. These effects were due to the Lys antiglycating and antioxidant effects, in addition to its protective effect against α-crystallin chaperoning activity.

Spices and Atherosclerosis

Cardiovascular disease is one of the leading causes of death and disability in the world. Atherosclerosis, characterized by lipid accumulation and chronic inflammation in the vessel wall, is the main feature of cardiovascular disease. Although the amounts of fruits and vegetables present in the diets vary by country, diets, worldwide, contain large amounts of spices; this may have positive or negative effects on the initiation and development of atherosclerosis. In this review, we focused on the potential protective effects of specific nutrients from spices, such as pepper, ginger, garlic, onion, cinnamon and chili, in atherosclerosis and atherosclerotic cardiovascular disease. The mechanisms, epidemiological analysis, and clinical studies focusing on a variety of spices are covered in this review. Based on the integrated information, we aimed to raise specific recommendations for people with different dietary styles for the prevention of atherosclerotic cardiovascular disease through dietary habit adjustments.

High-glucose-induced changes in macrophage secretome: regulation of immune response

Secretory products from infiltrating macrophages have been thought to play crucial roles in development and progression of diabetic complications in various tissues/organs. Nevertheless, diabetes-induced changes in macrophage secretory products remained largely unknown. We thus analyzed high-glucose (HG)-induced changes in secretome of human macrophages derived from U937 human monocytic cell line after phorbol 12-myristate 13-acetate (PMA) activation. Serum-free culture supernatants were collected from macrophages exposed to 5.5 mM glucose (NG-M-sup) (normal control), 25 mM glucose (HG-M-sup), or 5.5 mM glucose + 19.5 mM mannitol (MN-M-sup) (osmotic control) for 16 h. After dialysis and lyophilization, secreted proteins were subjected to 2-DE analysis (n = 5 gels derived from 5 independent cultures per group). Quantitative analysis and statistics revealed 23 protein spots whose secretory levels significantly differed among the three conditions. These proteins were successfully identified by nanoLC-ESI-MS/MS analyses and changes in levels of heat shock protein 90 (HSP90), HSP70, HSP60, and β-actin were confirmed by Western blotting. Global protein network and functional enrichment analyses revealed that the altered proteins in HG-M-sup were involved mainly in regulation of immune response that might communicate with other bystander cells through the release of extracellular vesicles. These data may lead to a wider view of pathogenic mechanisms of diabetic complications.

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.

Chemosensitizing effect of Paris Saponin I on Camptothecin and 10-hydroxycamptothecin in lung cancer cells via p38 MAPK, ERK, and Akt signaling pathways

Paris Saponin I (PSI), a steroidal sponins isolated from plant, has been exhibited antitumor and many other biological activities. In this study, we investigated the role and underlying mechanisms of PSI in the synergistic regulation of antitumor activity of Camptothecin (CPT) and 10-hydroxycamptothecin (HCPT) in four types of lung cancer cells. The inhibitory evaluation showed that PSI could significantly reduce the CPT/HCPT-mediated cell proliferation and enhance the sensitivities of H1299, H460 and H446 lung cancer cells to CPT/HCPT. Mechanism study indicated that PSI improved the CPT/HCPT induced apoptosis in lung cancer cells through mitochondria pathway including cytochrome C release and activation of caspase-9 and -3 cascades. Furthermore, PSI plus CPT/HCPT also increased the up-regulation of Bax and down-regulation of Bcl-2 and Bcl-XL in H460 and H446 cells. Moreover, PSI enhanced CPT/HCPT-mediated inhibition of p38 MAPK and activation of phosphorylation of p38 MAPK in H1299 cells, and suppression of Akt and ERK pathways activation in H460 cells as well as in H446 cells. Collectively, our results demonstrated that PSI functions as a chemosensitizer by enhancing apoptosis through influencing p38 MAPK, ERK, and Akt pathways in lung cancer cells, and the combination with CPT/HCPT might be a promising strategy for the development of new therapeutic agents.