Potential of Hibiscus sabdariffa Linn. polyphenol-rich extract in improving diabetes-induced vascular functional and structural abnormalities in rats

Hibiscus sabdariffa Linn. contains a high concentration of polyphenolic compounds and shows potentials in reducing vascular complications in diabetes mellitus (DM) patients. This study was aimed to determine the ability of H. sabdariffa Linn. polyphenol-rich extract (HPE) in improving vascular endothelial dysfunction and attenuating oxidative stress in type 1 DM. DM was induced in adult male rats and the rats were then divided into three groups; untreated DM (DM); DM with HPE supplementation (DM+HPE); and DM with metformin (DM+MET). Another group of non-diabetic rats served as the normal control group. These rats were left untreated for four weeks before being subjected to the supplementations for another four weeks. The thoracic descending aorta was isolated from the treated and untreated rats to measure the vascular reactivity, oxidative stress, and morphological alterations. The results showed that HPE supplementation significantly reduced the systolic blood pressure (SBP) and mean arterial pressure (MAP) in the DM+HPE group (p<0.05). HPE also showed a tendency to improve endothelium-dependent vasorelaxation compared to the untreated diabetic rats. Rats treated with HPE exhibited a considerable improvement in the activities of antioxidants and significantly attenuated oxidative damage (p<0.05). Histological findings showed that HPE supplementation improved morphological changes in the aorta. In conclusion, HPE supplementation reduces vascular abnormalities in DM condition probably via amelioration of oxidative stress

Pemodelan semula jantung dalam kardiomiopati diabetes: peranan inflamasi, tekanan oksidatif dan apoptosis yang mendasari pembentukan dan perkembangannya

Kardiomiopati diabetes (DCM) merupakan komplikasi kronik diabetes melitus akibat daripada perubahan pada fungsi dan struktur jantung yang diaruh oleh keadaan aras gula darah yang tinggi (hiperglisemia) secara berpanjangan. Walaupun pengawalan hiperglisemia dilakukan dengan komprehensif serta perubahan gaya hidup yang lebih sihat, komplikasi kardiovaskular termasuklah DCM terus menjadi antara punca kematian utama pesakit diabetes. Pembentukan dan perkembangan DCM adalah akibat proses kompensasi melalui pemodelan semula jantung yang melibatkan kematian kardiomiosit hasil daripada kerosakan oksidatif, apoptosis dan inflamasi susulan aruhan hiperglisemia yang tidak terkawal. Walaupun permodelan semula jantung merupakan proses yang penting dalam memulihara struktur dan fungsi jantung, namun dalam keadaan diabetes, rangsangan pemodelan semula jantung yang berpanjangan boleh membawa kepada kemorosotan fungsi yang kekal dan akhirnya menyebabkan kegagalan jantung. Memahami mekanisme yang terlibat dalam pembentukan dan perkembangan DCM adalah sangat penting bagi merangka strategi untuk mengurangkan komplikasi akibat penyakit ini. Oleh itu, dalam kertas ulasan ini, hasil kajian terkini mengenai proses pemodelan semula jantung dalam perkembangan DCM dan mekanisme utama yang mendasari pembentukan dan perkembangannya akan diperjelaskan

Hibiscus sabdariffa Linn. (Roselle) polyphenols-rich extract prevents hyperglycemia-induced cardiac oxidative stress and mitochondrial damage in diabetic rats

Cardiac mitochondrial damage plays a crucial role in the initiation of diabetic cardiomyopathy. Hibiscus sabdariffa Linn. (roselle) has been proven to prevent various pathological conditions, however it remains unclear whether roselle extract can attenuate diabetes-induced mitochondrial damage. This study aimed to investigate whether roselle polyphenol-rich extract (HPE) is able to ameliorate hyperglycemia-induced oxidative stress and mitochondrial damage in diabetic rats. Diabetes was induced by a single dose of streptozotocin (55 mg kg-1, intraperitoneally); and diabetic rats were then orally fed with 100 mg kg-1 of HPE (DM+Roselle) or 150 mg kg-1 of Metformin (DM+MET) daily for 4 weeks. Meanwhile, the control and untreated diabetic (DM) groups were only orally given normal saline. After 4 weeks of treatment, the results showed that DM+Roselle group significantly improved blood glucose level and lipid profile status (p<0.05) compared to the DM group. DM+Roselle group also had significantly (p<0.05) lower the level of thiobarbituric acid reactive substances (TBARS) and advanced oxidation protein product (AOPP) in cardiac homogenate than the DM group. HPE supplementation also significantly improved activities of total superoxide dismutase (SOD), SOD-2, catalase (CAT) and level of reduced glutathione (GSH) of the cardiac homogenate. Complex I activity of mitochondria respiratory chain also decreased significantly (p<0.05) in DM+Roselle group as compared to the DM group. Observations using electron microscope showed that mitochondria in the DM+Roselle group appeared more organized compared to the DM group. In conclusion, these results highlight the potential of HPE as a protective agent against oxidative stress and mitochondrial damage in diabetic condition

The Potential Role of Flavonoids in Ameliorating Diabetic Cardiomyopathy via Alleviation of Cardiac Oxidative Stress, Inflammation and Apoptosis

Diabetic cardiomyopathy is one of the major mortality risk factors among diabetic patients worldwide. It has been established that most of the cardiac structural and functional alterations in the diabetic cardiomyopathy condition resulted from the hyperglycemia-induced persistent oxidative stress in the heart, resulting in the maladaptive responses of inflammation and apoptosis. Flavonoids, the most abundant phytochemical in plants, have been reported to exhibit diverse therapeutic potential in medicine and other biological activities. Flavonoids have been widely studied for their effects in protecting the heart against diabetes-induced cardiomyopathy. The potential of flavonoids in alleviating diabetic cardiomyopathy is mainly related with their remedial actions as anti-hyperglycemic, antioxidant, anti-inflammatory, and anti-apoptotic agents. In this review, we summarize the latest findings of flavonoid treatments on diabetic cardiomyopathy as well as elucidating the mechanisms involved

The Role of Polyphenol in Modulating Associated Genes in Diabetes-Induced Vascular Disorders

Diabetes-induced vascular disorder is considered one of the deadly risk factors among diabetic patients that are caused by persistent hyperglycemia that eventually leads to cardiovascular diseases. Elevated reactive oxygen species (ROS) due to high blood glucose levels activate signaling pathways such as AGE/RAGE, PKC, polyol, and hexosamine pathways. The activated signaling pathway triggers oxidative stress, inflammation, and apoptosis which later lead to vascular dysfunction induced by diabetes. Polyphenol is a bioactive compound that can be found abundantly in plants such as vegetables, fruits, whole grains, and nuts. This compound exerts therapeutic effects in alleviating diabetes-induced vascular disorder, mainly due to its potential as an anti-oxidative, anti-inflammatory, and anti-apoptotic agent. In this review, we sought to summarize the recent discovery of polyphenol treatments in modulating associated genes involved in the progression of diabetes-induced vascular disorder

Therapeutic Approach of Flavonoid in Ameliorating Diabetic Cardiomyopathy by Targeting Mitochondrial-Induced Oxidative Stress

Diabetes cardiomyopathy is one of the key factors of mortality among diabetic patients around the globe. One of the prior contributors to the progression of diabetic cardiomyopathy is cardiac mitochondrial dysfunction. The cardiac mitochondrial dysfunction can induce oxidative stress in cardiomyocytes and was found to be the cause of majority of the heart morphological and dynamical changes in diabetic cardiomyopathy. To slow down the occurrence of diabetic cardiomyopathy, it is crucial to discover therapeutic agents that target mitochondrial-induced oxidative stress. Flavonoid is a plentiful phytochemical in plants that shows a wide range of biological actions against human diseases. Flavonoids have been extensively documented for their ability to protect the heart from diabetic cardiomyopathy. Flavonoids’ ability to alleviate diabetic cardiomyopathy is primarily attributed to their antioxidant properties. In this review, we present the mechanisms involved in flavonoid therapies in ameliorating mitochondrial-induced oxidative stress in diabetic cardiomyopathy

The Role of PKC-MAPK Signalling Pathways in the Development of Hyperglycemia-Induced Cardiovascular Complications

Cardiovascular disease is the most common cause of death among diabetic patients worldwide. Hence, cardiovascular wellbeing in diabetic patients requires utmost importance in disease management. Recent studies have demonstrated that protein kinase C activation plays a vital role in the development of cardiovascular complications via its activation of mitogen-activated protein kinase (MAPK) cascades, also known as PKC-MAPK pathways. In fact, persistent hyperglycaemia in diabetic conditions contribute to preserved PKC activation mediated by excessive production of diacylglycerol (DAG) and oxidative stress. PKC-MAPK pathways are involved in several cellular responses, including enhancing oxidative stress and activating signalling pathways that lead to uncontrolled cardiac and vascular remodelling and their subsequent dysfunction. In this review, we discuss the recent discovery on the role of PKC-MAPK pathways, the mechanisms involved in the development and progression of diabetic cardiovascular complications, and their potential as therapeutic targets for cardiovascular management in diabetic patients

Therapeutic Potential of <i>Hibiscus sabdariffa</i> Linn. in Attenuating Cardiovascular Risk Factors

Cardiovascular diseases (CVDs) represent a broad spectrum of diseases afflicting the heart and blood vessels and remain a major cause of death and disability worldwide. CVD progression is strongly associated with risk factors, including hypertension, hyperglycemia, dyslipidemia, oxidative stress, inflammation, fibrosis, and apoptosis. These risk factors lead to oxidative damage that results in various cardiovascular complications including endothelial dysfunctions, alterations in vascular integrity, the formation of atherosclerosis, as well as incorrigible cardiac remodeling. The use of conventional pharmacological therapy is one of the current preventive measures to control the development of CVDs. However, as undesirable side effects from drug use have become a recent issue, alternative treatment from natural products is being sought in medicinal plants and is gaining interest. Roselle (Hibiscus sabdariffa Linn.) has been reported to contain various bioactive compounds that exert anti-hyperlipidemia, anti-hyperglycemia, anti-hypertension, antioxidative, anti-inflammation, and anti-fibrosis effects. These properties of roselle, especially from its calyx, have relevance to its therapeutic and cardiovascular protection effects in humans. This review summarizes the findings of recent preclinical and clinical studies on roselle as a prophylactic and therapeutic agent in attenuating cardiovascular risk factors and associated mechanisms