The Cardioprotective Effects of Aminoguanidine on Lipopolysaccharide Induced Inflammation in Rats

Role of advanced glycation end-products in age-associated kidney dysfunction in naturally aging mice

AIMS

Advanced glycation end-products (AGEs) are implicated in the age-related decline of renal function, exacerbated by conditions, such as hyperglycemia and oxidative stress. The accumulation of AGEs in the kidneys contributes to the progressive decline in renal function observed with aging. However, the precise role and mechanisms of AGEs in the age-related decline of renal function remain unclear. In this study, we investigated the impact and potential mechanisms of AGEs on aging kidneys in naturally aging mice.

MATERIALS AND METHODS

Male C57BL/6 mice were divided into three groups: 6-, 57-, and 107-week-old. First, the 6- and 107-week-old mice were euthanized. The remaining mice were divided into young (6 weeks) and old (57 weeks) groups. The 57-week-old mice were orally administered aminoguanidine (100 mg/kg/day), an AGEs inhibitor, or vehicle for 13 weeks, resulting in a final age of 70 weeks. The serum and kidney tissues were collected for biochemical measurement, histological examination, immunohistochemistry staining, and immunoblotting analysis.

KEY FINDINGS

Our findings revealed a notable accumulation of AGEs in both serum and kidney tissue specimens and renal dysfunction in naturally aging mice. Aminoguanidine not only reversed AGEs accumulation but also ameliorated renal dysfunction. Additionally, aminoguanidine attenuated the upregulation of fibrosis markers (phosphorylated p38/α-SMA and C/EBP homologous protein, CHOP), senescence markers (p53 and p21), and oxidative stress marker (4-HNE) in the aging kidneys.

SIGNIFICANCE

These findings underscore the critical role of AGEs in age-related renal dysfunction and highlight the therapeutic potential of aminoguanidine in mitigating fibrosis and senescence, offering prospective avenues for combating age-associated renal ailments.

Endothelial cell dysfunction and targeted therapeutic drugs in sepsis

Sepsis is a life-threatening organ dysfunction caused by an abnormal host response to microbial infections. During its pathogenesis, vascular endothelial cells (ECs) play a pivotal role as essential components in maintaining microcirculatory homeostasis. This article aims to comprehensively review the multifaceted physiological functions of vascular ECs, elucidate the alterations in their functionality throughout the course of sepsis, and explore recent advancements in research concerning sepsis-related therapeutic drugs targeting ECs.

The effects of vitamin D on cardiovascular damage induced by lipopolysaccharides in rats

Introduction

Inflammation and oxidative stress are contributed to cardiovascular diseases. Vitamin D (Vit D) has antioxidant and anti-inflammatory properties. In the current research, the effect of Vit D on cardiac fibrosis and inflammation, and oxidative stress indicators in cardiovascular tissues was studied in lipopolysaccharides(LPS) injected rats.

Methods

Rats were distributed into 5 groups and were treated for 2 weeks. Control: received vehicle(saline supplemented with tween-80) instead of Vit D and saline instead of LPS, LPS: treated by 1 mg/kg of LPS and was given vehicle instead of Vit D, LPS-Vit D groups: received 3 doses of Vit D (100, 1000, and 10000 IU/kg) of Vit D in addition to LPS. Vit D was dissolved in saline supplemented with tween-80 (final concentration 0.1%) and LPS was dissolved in saline. The white blood cell (WBC) was counted. Oxidative stress markers were determined in serum, aorta, and heart. Cardiac tissue fibrosis was also estimated using Masson's trichrome staining method.

Results

WBC and malondialdehyde (MDA) were higher in the LPS group than the control group, whereas the thiol content, superoxide dismutase (SOD), and catalase (CAT) were lower in the LPS group than the control group (P<0.01 and P<0.001). Administration of Vit D decreased WBC (P<0.001) and MDA (P<0.05 and P<0.001) while enhanced thiol (dose 10000 IU/Kg) (P<0.001), SOD (dose 10000 IU/kg) (P<0.001), and CAT (P<0.05 and P<0.001) compared to the LPS group. All doses of Vit D also decreased cardiac fibrosis compared to the LPS group (P<0.001).

Conclusion

Vit D protected the cardiovascular against the detrimental effect of LPS. This cardiovascular protection can be attributed to the antioxidant and anti-inflammatory properties of Vit D.

Diabetic cardiomyopathy was attenuated by cinnamon treatment through the inhibition of fibro-inflammatory response and ventricular hypertrophy in diabetic rats

Diabetic cardiomyopathy (DCM) is a chronic complication of diabetes that emphasizes the urgency of developing new drug therapies. With an illustrious history in traditional medicine to improve diabetes, cinnamon has been shown to possess blood lipids lowering effects and antioxidative and anti-inflammatory properties. However, the extent to which it protects the diabetic heart has yet to be determined. Forty-eight rats were administered in the study and grouped as: control; diabetic; diabetic rats given 100, 200, or 400 mg/kg cinnamon extract, metformin (300 mg/kg), valsartan (30 mg/kg), or met/val (combination of both drugs), via gavage for six weeks. Fasting blood sugar (FBS) and markers of cardiac injury including creatine kinase-muscle/brain (CK-MB), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) were evaluated in blood samples. Malondialdehyde (MDA) levels, the total contents of thiol, superoxide dismutase (SOD), and catalase (CAT) activities were measured. Histopathology study and gene expression measurement of angiotensin II type 1 receptor (AT1), atrial natriuretic peptide (ANP), beta-myosin heavy chain (β-MHC), and brain natriuretic peptide (BNP) were done on cardiac tissue. FBS and cardiac enzyme indicators were reduced in all treated groups. A reduction in MDA level and enhancement in thiol content alongside with increase of SOD and CAT activities were observed in extract groups. The decrease of inflammation and fibrosis was obvious in treated groups, notably in the high-dose extract group. Furthermore, all treated diabetic groups showed a lowering trend in AT1, ANP, β-MHC, and BNP gene expression. Cinnamon extract, in addition to its hypoglycemic and antioxidant properties, can prevent diabetic heart damage by alleviating cardiac inflammation and fibrosis. PRACTICAL APPLICATIONS: This study found that cinnamon extract might protect diabetic heart damage by reducing inflammation and fibrosis in cardiac tissue, in addition to lowering blood glucose levels and increasing antioxidant activity. Our data imply that including cinnamon in diabetic participants' diets may help to reduce risk factors of cardiovascular diseases.

Tectona grandis leaf extract ameliorates hepatic fibrosis: Modulation of TGF- β /Smad signaling pathway and upregulating MMP3/TIMP1 ratio

ETHNOBOTANICAL RELEVANCE

Tectona grandis L.f (or syn: Jatus grandis (L.f.) Kuntze Revis), from family Lamiaceae, also known as Teak, is widely recognized in ayurvedic system of medicine and confer curative potential against inflammation, liver disorders, biliousness, diabetes, bronchitis, leprosy and dysentery. Its leaves are rich source of edible food colorant and reported nontoxic for liver and various organs.

AIM OF STUDY

Hepatic injury progression to liver cirrhosis and cancer is a serious health issue across the world. Currently, anti-fibrotic therapeutic options are limited and expensive with no FDA approved direct anti-hepato-fibrotic drug validated in clinic. Thus, the aim of this study was to understand ameliorative effect of Tectona grandis L.f, leaves in early liver fibrosis.

METHOD AND RESULTS

C57BL/6 mice suffering from CCl4 induced liver injury, were orally administered at three different doses (50, 100 & 200 mg/kg) of Tectona grandis L.f, leaf extract, thrice a week, up to 4 and 8 weeks. Anti-fibrotic effect was evaluated through animal body/liver weight measurements, serological tests (AST, ALT, GSH, MDA and LDH assays), tissue hydroxyproline content, and histochemical analysis (H&E, Masson trichrome, Sirius red and αSMA localization). Moreover, transcriptional and post-transcriptional expression of fibrosis associated biomarkers and TGF-β/Smad cascade were analyzed. It was observed that 100 mg/kg dose optimally downregulated TGF-β1/Smad2 with upregulation of Smad7 and regulated αSMA, Col 1, PDGF, TIMP1 and MMP3 expression, post 8 weeks of treatment. In addition, MMP3/TIMP1 ratio was upregulated to 0.7, 2.5 and 1.7 fold at 50 mg/kg, 100 mg/kg & 200 mg/kg treatments respectively, in comparison to untreated liver fibrosis models. The extract contains gallic acid, caffeic acid, sinapinic acid and myricetin when analyzed through high performance liquid chromatography.

CONCLUSION

Tectona grandis L.f, leaves have potential to ameliorate liver fibrosis induced by CCl4 in mice via modulation of TGF-β1/Smad pathway and upregulated MMP3/TIMP1 ratio.