An ethanolic-aqueous extract of Curcuma longa decreases the susceptibility of liver microsomes and mitochondria to lipid peroxidation in atherosclerotic rabbits

Curcumin and analogues in mitigating liver injury and disease consequences: From molecular mechanisms to clinical perspectives

BACKGROUND

Liver injury is a prevalent global health concern, impacting a substantial number of individuals and leading to elevated mortality rates and socioeconomic burdens. Traditional primary treatment options encounter resource constraints and high costs, prompting exploration of alternative adjunct therapies, such as phytotherapy. Curcumin demonstrates significant therapeutic potential across various medical conditions, particularly emerging as a promising candidate for liver injury treatment.

PURPOSE

This study aims to provide current evidence maps of curcumin and its analogs in the context of liver injury, covering aspects of biosafety, toxicology, and clinical trials. Importantly, it seeks to summarize the intricate mechanisms modulated by curcumin.

METHODS

We conducted a comprehensive search of MEDLINE, Web of Science, and Embase up to July 2023. Titles and abstracts were reviewed to identify studies that met our eligibility criteria. The screening process involved three authors independently assessing the potential of curcumin mitigating liver injury and its disease consequences by reviewing titles, abstracts, and full texts.

RESULTS

Curcumin and its analogs have demonstrated low toxicity in vitro and in vivo. However, the limited bioavailability has hindered their advanced use in liver injury. This limitation can potentially be addressed by nano-curcumin and emerging drug delivery systems. Curcumin plays a role in alleviating liver injury by modulating the antioxidant system, as well as cellular and molecular pathways. The specific mechanisms involve multiple pathways, such as NF-κB, p38/MAPK, and JAK2/STAT3, and the pro-apoptosis Bcl-2/Bax/caspase-3 axis in damaged cells. Additionally, curcumin targets nutritional metabolism, regulating the substance in liver cells and tissues. The microenvironment associated with liver injury, like extracellular matrix and immune cells and factors, is also regulated by curcumin. Initial evaluation of curcumin and its analogs through 12 clinical trials demonstrates their potential application in liver injury.

CONCLUSION

Curcumin emerges as a promising phytomedicine for liver injury owing to its effectiveness in hepatoprotection and low toxicity profile. Nevertheless, in-depth investigations are warranted to unravel the complex mechanisms through which curcumin influences liver tissues and overall physiological milieu. Moreover, extensive clinical trials are essential to determine optimal curcumin dosage forms, maximizing its benefits and achieving favorable clinical outcomes.

From Obesity-Induced Low-Grade Inflammation to Lipotoxicity and Mitochondrial Dysfunction: Altered Multi-Crosstalk between Adipose Tissue and Metabolically Active Organs

Obesity is a major risk factor for several metabolic diseases, including type 2 diabetes, hyperlipidemia, cardiovascular diseases, and brain disorders. Growing evidence suggests the importance of inter-organ metabolic communication for the progression of obesity and the subsequent onset of related disorders. This review provides a broad overview of the pathophysiological processes that from adipose tissue dysfunction leading to altered multi-tissue crosstalk relevant to regulating energy homeostasis and the etiology of obesity. First, a comprehensive description of the role of adipose tissue was reported. Then, attention was turned toward the unhealthy expansion of adipose tissue, low-grade inflammatory state, metabolic inflexibility, and mitochondrial dysfunction as root causes of systemic metabolic alterations. In addition, a short spot was devoted to iron deficiency in obese conditions and the role of the hepcidin-ferroportin relationship in the management of this issue. Finally, different classes of bioactive food components were described with a perspective to enhance their potential preventive and therapeutic use against obesity-related diseases.

In Vivo Anti-Alzheimer and Antioxidant Properties of Avocado (Persea americana Mill.) Honey from Southern Spain

There is growing evidence that Alzheimer's disease (AD) can be prevented by reducing risk factors involved in its pathophysiology. Food-derived bioactive molecules can help in the prevention and reduction of the progression of AD. Honey, a good source of antioxidants and bioactive molecules, has been tied to many health benefits, including those from neurological origin. Monofloral avocado honey (AH) has recently been characterized but its biomedical properties are still unknown. The aim of this study is to further its characterization, focusing on the phenolic profile. Moreover, its antioxidant capacity was assayed both in vitro and in vivo. Finally, a deep analysis on the pathophysiological features of AD such as oxidative stress, amyloid-β aggregation, and protein-tau-induced neurotoxicity were evaluated by using the experimental model C. elegans. AH exerted a high antioxidant capacity in vitro and in vivo. No toxicity was found in C. elegans at the dosages used. AH prevented ROS accumulation under AAPH-induced oxidative stress. Additionally, AH exerted a great anti-amyloidogenic capacity, which is relevant from the point of view of AD prevention. AH exacerbated the locomotive impairment in a C. elegans model of tauopathy, although the real contribution of AH remains unclear. The mechanisms under the observed effects might be attributed to an upregulation of daf-16 as well as to a strong ROS scavenging activity. These results increase the interest to study the biomedical applications of AH; however, more research is needed to deepen the mechanisms under the observed effects.

Protective Effects of Curcumin in Cardiovascular Diseases—Impact on Oxidative Stress and Mitochondria

Cardiovascular diseases (CVDs) contribute to a large part of worldwide mortality. Similarly, two of the major risk factors for these diseases, aging and obesity, are also global problems. Aging, the gradual decline of body functions, is non-modifiable. Obesity, a modifiable risk factor for CVDs, also predisposes to type 2 diabetes mellitus (T2DM). Moreover, it affects not only the vasculature and the heart but also specific fat depots, which themselves have a major impact on the development and progression of CVDs. Common denominators of aging, obesity, and T2DM include oxidative stress, mitochondrial dysfunction, metabolic abnormalities such as altered lipid profiles and glucose metabolism, and inflammation. Several plant substances such as curcumin, the major active compound in turmeric root, have been used for a long time in traditional medicine and for the treatment of CVDs. Newer mechanistic, animal, and human studies provide evidence that curcumin has pleiotropic effects and attenuates numerous parameters which contribute to an increased risk for CVDs in aging as well as in obesity. Thus, curcumin as a nutraceutical could hold promise in the prevention of CVDs, but more standardized clinical trials are required to fully unravel its potential.

Natural Bioactive Compounds as Potential Browning Agents in White Adipose Tissue

The epidemic of overweight and obesity underlies many common metabolic diseases. Approaches aimed to reduce energy intake and/or stimulate energy expenditure represent potential strategies to control weight gain. Adipose tissue is a major energy balancing organ. It can be classified as white adipose tissue (WAT) and brown adipose tissue (BAT). While WAT stores excess metabolic energy, BAT dissipates it as heat via adaptive thermogenesis. WAT also participates in thermogenesis by providing thermogenic fuels and by directly generating heat after browning. Browned WAT resembles BAT morphologically and metabolically and is classified as beige fat. Like BAT, beige fat can produce heat. Human adults have BAT-like or beige fat. Recruitment and activation of this fat type have the potential to increase energy expenditure, thereby countering against obesity and its metabolic complications. Given this, agents capable of inducing WAT browning have recently attracted broad attention from biomedical, nutritional and pharmaceutical societies. In this review, we summarize natural bioactive compounds that have been shown to promote beige adipocyte recruitment and activation in animals and cultured cells. We also discuss potential molecular mechanisms for each compound to induce adipose browning and metabolic benefits.

Biochemical study on the protective effect of curcumin on acetaminophen and gamma-irradiation induced hepatic toxicity in rats

Acetaminophen (APAP) is one of the few recommended analgesic and antipyretic drugs in some critical cases such as viral disease COVID-19. However, the unrestricted use of APAP develops liver disorders. Hepatotoxicity and liver injury can also be induced by ionizing radiation (IR) during radiotherapy. The data of the current study represents that treatment of rats with either APAP-overdose, or gamma-irradiation (R) induces hepatotoxicity, results in significant increases of the hepatic-enzymes activities (ALT, AST, ALP, GGT, LDH, and MDH), as well as enhancement of triglycerides, total cholesterol levels, combined with declines in albumin and total protein contents. An enhancement of the lipid peroxides (malondialdehyde; MDA), and nitric oxide levels along with a decline of reduced glutathione contents and suppression of superoxide dismutase, catalase, and glutathione peroxidase activities are also observed within the liver tissues of intoxicated animals. TNF-α, IL-1β, IL-6, iNOS, Cytochrome P450 2E1 (CYP2E1), miR-802 gene expression, NF-κB, and calcium levels are up-regulated, while Nuclear factor erythroid-related factor-2 (Nrf2), Hemoxygenase-1 (HO-1) protein and gene expressions, as well as, glutamate-cysteine ligase catalytic subunit (GCLC), NAD(P)H-Quinone oxidoreductase (NQO1), and miR-122 gene expressions are down-regulated in the livers of intoxicated animals. All these parameters show significant improvement in R/APAP intoxicated animals. Curcumin pretreatment develops an amelioration of these effects in APAP-overdose, R-exposure, or R/APAP treatments. In conclusion, oral administration of curcumin shows hepatoprotective effects against APAP-overdose induced hepatic damage in normal and gamma-irradiated rats through prospective regulation of the therapeutic targets CYP2E1, Nrf2, and NF-κB, via organizing the miR-122 and miR-802 gene expression.

Therapeutic Applications of Curcumin Nanomedicine Formulations in Cardiovascular Diseases

Cardiovascular diseases (CVD) compromises a group of heart and blood vessels disorders with high impact on human health and wellbeing. Curcumin (CUR) have demonstrated beneficial effects on these group of diseases that represent a global burden with a prevalence that continues increasing progressively. Pre- and clinical studies have demonstrated the CUR effects in CVD through its anti-hypercholesterolemic and anti-atherosclerotic effects and its protective properties against cardiac ischemia and reperfusion. However, the CUR therapeutic limitation is its bioavailability. New CUR nanomedicine formulations are developed to solve this problem. The present article aims to discuss different studies and approaches looking into the promising role of nanotechnology-based drug delivery systems to deliver CUR and its derivatives in CVD treatment, with an emphasis on their formulation properties, experimental evidence, bioactivity, as well as challenges and opportunities in developing these systems.

Augmentation of therapeutic potential of curcumin using nanotechnology: current perspectives

Curcumin, an active principle of Curcuma longa, is extracted from the rhizome. Its therapeutic efficiency has been proved using various in vitro and in vivo models. Inflammatory, neoplastic and preneoplastic diseases are the major targets using curcumin as therapeutic agent. Feasible clinical formulations could not be obtained because of its lack of solubility, stability and higher degradation rate. Recently, many techniques have been evolved to improve the physicochemical properties of pharmacological compounds, thereby increasing their biological activity. Curcumin has been developed using various techniques, particularly micro and nanotechnology to improve its stability and bioavailability. This review focuses on the studies pertaining to the delivery of curcumin in the form of micro and nanosize formulations for the treatment of a variety of diseases.

Multitargeting by turmeric, the golden spice: From kitchen to clinic

Although much has been published about curcumin, which is obtained from turmeric, comparatively little is known about turmeric itself. Turmeric, a golden spice obtained from the rhizome of the plant Curcuma longa, has been used to give color and taste to food preparations since ancient times. Traditionally, this spice has been used in Ayurveda and folk medicine for the treatment of such ailments as gynecological problems, gastric problems, hepatic disorders, infectious diseases, and blood disorders. Modern science has provided the scientific basis for the use of turmeric against such disorders. Various chemical constituents have been isolated from this spice, including polyphenols, sesquiterpenes, diterpenes, triterpenoids, sterols, and alkaloids. Curcumin, which constitutes 2-5% of turmeric, is perhaps the most-studied component. Although some of the activities of turmeric can be mimicked by curcumin, other activities are curcumin-independent. Cell-based studies have demonstrated the potential of turmeric as an antimicrobial, insecticidal, larvicidal, antimutagenic, radioprotector, and anticancer agent. Numerous animal studies have shown the potential of this spice against proinflammatory diseases, cancer, neurodegenerative diseases, depression, diabetes, obesity, and atherosclerosis. At the molecular level, this spice has been shown to modulate numerous cell-signaling pathways. In clinical trials, turmeric has shown efficacy against numerous human ailments including lupus nephritis, cancer, diabetes, irritable bowel syndrome, acne, and fibrosis. Thus, a spice originally common in the kitchen is now exhibiting activities in the clinic. In this review, we discuss the chemical constituents of turmeric, its biological activities, its molecular targets, and its potential in the clinic.

Targeting inflammation-induced obesity and metabolic diseases by curcumin and other nutraceuticals

Extensive research within the past two decades has revealed that obesity, a major risk factor for type 2 diabetes, atherosclerosis, cancer, and other chronic diseases, is a proinflammatory disease. Several spices have been shown to exhibit activity against obesity through antioxidant and anti-inflammatory mechanisms. Among them, curcumin, a yellow pigment derived from the spice turmeric (an essential component of curry powder), has been investigated most extensively as a treatment for obesity and obesity-related metabolic diseases. Curcumin directly interacts with adipocytes, pancreatic cells, hepatic stellate cells, macrophages, and muscle cells. There, it suppresses the proinflammatory transcription factors nuclear factor-kappa B, signal transducer and activators of transcription-3, and Wnt/beta-catenin, and it activates peroxisome proliferator-activated receptor-gamma and Nrf2 cell-signaling pathways, thus leading to the downregulation of adipokines, including tumor necrosis factor, interleukin-6, resistin, leptin, and monocyte chemotactic protein-1, and the upregulation of adiponectin and other gene products. These curcumin-induced alterations reverse insulin resistance, hyperglycemia, hyperlipidemia, and other symptoms linked to obesity. Other structurally homologous nutraceuticals, derived from red chili, cinnamon, cloves, black pepper, and ginger, also exhibit effects against obesity and insulin resistance.

An aqueous extract of Curcuma longa (turmeric) rhizomes stimulates insulin release and mimics insulin action on tissues involved in glucose homeostasis in vitro

Curcuma longa (turmeric) has been used widely as a spice, particularly in Asian countries. It is also used in the Ayurvedic system of medicine as an antiinflammatory and antimicrobial agent and for numerous other curative properties. The aim of this study was to investigate the effects of an aqueous extract of Curcuma longa (AEC) on tissues involved in glucose homeostasis. The extract was prepared by soaking 100 g of ground turmeric in 1 L of water, which was filtered and stored at -20°C prior to use. Pancreas and muscle tissues of adult mice were cultured in DMEM with 5 or 12 mmol/L glucose and varying doses of extract. The AEC stimulated insulin secretion from mouse pancreatic tissues under both basal and hyperglycaemic conditions, although the maximum effect was only 68% of that of tolbutamide. The AEC induced stepwise stimulation of glucose uptake from abdominal muscle tissues in the presence and absence of insulin, and the combination of AEC and insulin significantly potentiated the glucose uptake into abdominal muscle tissue. However, this effect was attenuated by wortmannin, suggesting that AEC possibly acts via the insulin-mediated glucose uptake pathway. In summary, water soluble compounds of turmeric exhibit insulin releasing and mimicking actions within in vitro tissue culture conditions.

New advances in molecular mechanisms and the prevention of adriamycin toxicity by antioxidant nutrients

Anthracyclines (doxorubicin, daunorubicin, epirubicin, and idarubicin) are currently the most effective group of anti-neoplastic drugs used in clinical practice. Of these, doxorubicin (also called adriamycin) is a key chemotherapeutic agent in cancer treatment, although its use is limited as a consequence of the chronic and acute toxicity associated with this drug. The molecular mechanisms of doxorubicin account for both the anti-cancer and the toxic side effects. Many antioxidants have been assayed, with positive or negative results, to prevent the toxicity of doxorubicin. The present review has two main goals: (1) to report the latest findings regarding the molecular mechanisms of doxorubicin toxicity; (2) to update our understanding of the role of natural antioxidants in preventive therapy against doxorubicin-induced toxicity. This review provides new evidence for the chemoprevention of doxorubicin toxicity, making use of natural antioxidants - in particular vitamin E, vitamin C, coenzyme Q, carotenoids, vitamin A, flavonoids, polyphenol, resveratrol, antioxidant from virgin olive oil and selenium - and offers new insights into the molecular mechanisms of doxorubicin toxicity with respect to DNA damage, free radicals and other parameters.

The functional assessment of Alpinia pricei on metabolic syndrome induced by sucrose-containing drinking water in mice

This study was designed to test whether Alpinia pricei (AP), a member of the ginger family indigenous to Taiwan, reduced metabolic syndrome induced by sucrose-containing drinking water in C57BL/6J mice. Mice given a chow diet were divided into a control group (C) or a test group given 30% sucrose water (SW) to drink ad libitum. After 22 weeks, mice in the SW group were subdivided into SW and SW + AP groups, the latter receiving a chow diet with an ethanol extract of AP (1500 mg/kg dosage). Four weeks later, bio-indexes associated with metabolic syndrome were measured. Compared with the C group, the SW group had significantly higher body weight, visceral fat weights, serum and tissue lipid, serum insulin level and the area under the curve for blood glucose of the insulin tolerance test (p < 0.05). These indicators in the SW + AP group were lower than in the SW group except for serum lipid, although slightly higher than the C group. The SW + AP group also showed significantly lower serum levels of leptin and tumor necrosis factor-alpha and a significantly higher level of adiponectin than the SW group. These results indicated that visceral adiposity and insulin resistance induced by sucrose water drinking might be alleviated by AP supplementation.

Potential therapeutic effects of curcumin, the anti-inflammatory agent, against neurodegenerative, cardiovascular, pulmonary, metabolic, autoimmune and neoplastic diseases

Although safe in most cases, ancient treatments are ignored because neither their active component nor their molecular targets are well defined. This is not the case, however, with curcumin, a yellow-pigment substance and component of turmeric (Curcuma longa), which was identified more than a century ago. For centuries it has been known that turmeric exhibits anti-inflammatory activity, but extensive research performed within the past two decades has shown that this activity of turmeric is due to curcumin (diferuloylmethane). This agent has been shown to regulate numerous transcription factors, cytokines, protein kinases, adhesion molecules, redox status and enzymes that have been linked to inflammation. The process of inflammation has been shown to play a major role in most chronic illnesses, including neurodegenerative, cardiovascular, pulmonary, metabolic, autoimmune and neoplastic diseases. In the current review, we provide evidence for the potential role of curcumin in the prevention and treatment of various proinflammatory chronic diseases. These features, combined with the pharmacological safety and negligible cost, render curcumin an attractive agent to explore further.

Oxidative stress status in liver mitochondria and lymphocyte DNA damage of atherosclerotic rabbits supplemented with water soluble coenzyme Q10

The effects of the administration of water soluble coenzyme Q10 (25 mg/kg per day) over 30 days, after 50 days feeding on a high-fat diet (3% lard + 1.3% cholesterol), were investigated in the plasma and liver mitochondria of rabbits. Results showed that this atherogenic diet enhanced lipid levels both in plasma and liver mitochondria, reduced plasma and mitochondrial concentrations of retinol and coenzyme Q10, led to higher DNA damage in peripheral blood lymphocytes and reactive oxygen species concentration in liver mitochondria. The treatment of animals with coenzyme Q10 reduced (to the healthy group levels) lipid concentration in liver mitochondria with no effect on plasma lipids, increased mitochondrial levels of alpha-tocopherol, restored mitochondrial coenzyme Q10 and improved alpha-tocopherol levels in plasma. Moreover, coenzyme Q10 supplementation reduced mitochondrial reactive oxygen species levels and decreased DNA damage in peripheral blood lymphocytes. The findings suggest that antioxidant therapy with coenzyme Q10 may be used in the treatment of liver pathologies associated to the intake of high-fat, atherogenic, diets.

Therapeutic potential of curcumin in non-alcoholic steatohepatitis

Non-alcoholic steatohepatitis (NASH) may be associated with a number of clinical conditions, but it occurs most commonly in patients with insulin resistance. There is as yet no established disease-modifying treatment, and a safe and broadly available agent that targets hepatic steatosis, insulin resistance, inflammation and fibrosis is necessary. The polyphenolic compound curcumin exhibits antioxidant and anti-inflammatory properties, inhibits NF-κB and activates PPAR-γ. In rodents, curcumin prevents dietary-induced hepatic steatosis, hepatic stellate cell activation and production of fibrotic proteins, and ameliorates steatohepatitis induced by the intake of alcohol or a methionine–choline-deficient diet. Indirect evidence suggests that curcumin may improve insulin sensitivity in diabetes and inflammatory states. The present paper reviews the numerous cellular and animal studies indicating that curcumin attenuates many of the pathophysiological processes involved in the development and progression of NASH. It is suggested that basic and clinical studies on curcumin in the development and progression of NASH are indicated.

CURCUMIN: THE INDIAN SOLID GOLD

Turmeric, derived from the plant Curcuma longa, is a gold-colored spice commonly used in the Indian subcontinent, not only for health care but also for the preservation of food and as a yellow dye for textiles. Curcumin, which gives the yellow color to turmeric, was first isolated almost two centuries ago, and its structure as diferuloylmethane was determined in 1910. Since the time of Ayurveda (1900 Bc) numerous therapeutic activities have been assigned to turmeric for a wide variety of diseases and conditions, including those of the skin, pulmonary, and gastrointestinal systems, aches, pains, wounds, sprains, and liver disorders. Extensive research within the last half century has proven that most of these activities, once associated with turmeric, are due to curcumin. Curcumin has been shown to exhibit antioxidant, anti-inflammatory, antiviral, antibacterial, antifungal, and anticancer activities and thus has a potential against various malignant diseases, diabetes, allergies, arthritis, Alzheimer's disease, and other chronic illnesses. These effects are mediated through the regulation of various transcription factors, growth factors, inflammatory cytokines, protein kinases, and other enzymes. Curcumin exhibits activities similar to recently discovered tumor necrosis factor blockers (e.g., HUMIRA, REMICADE, and ENBREL), a vascular endothelial cell growth factor blocker (e.g., AVASTIN), human epidermal growth factor receptor blockers (e.g., ERBITUX, ERLOTINIB, and GEFTINIB), and a HER2 blocker (e.g., HERCEPTIN). Considering the recent scientific bandwagon that multitargeted therapy is better than monotargeted therapy for most diseases, curcumin can be considered an ideal "Spice for Life".

Neuroprotective and Anti-ageing Effects of Curcumin in Aged Rat Brain Regions

This study investigated the influence of chronically administered curcumin on normal ageing-related parameters: lipid peroxidation, lipofuscin concentration and intraneuronal lipofuscin accumulation, activities of the enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx), and Na(+), K(+), -adenosine triphosphatase (Na(+), K(+), -ATPase) in different brain regions (cerebral cortex, hippocampus, cerebellum and medulla) of 6- and 24-month-old rats. In normal ageing, lipid peroxidation and lipofuscin concentration were found to increase with ageing, the activities of SOD, GPx and Na(+), K(+), -ATPase, however, decreased with ageing. Chronic curcumin treatment of both 6 and 24 months old rats resulted in significant decreases in lipid peroxide and the lipofuscin contents in brain regions, the activities of SOD, GPx and Na(+), K(+), -ATPase however, showed significant increase in various brain regions. The present study, thus, demonstrated the antioxidative, antilipofusinogenesic and anti-ageing effects of curcumin in the brain.

Antarth, a polyherbal preparation protects against the doxorubicin-induced toxicity without compromising its Antineoplastic activity

Doxorubicin (DOX), an anthracycline drug widely used for the treatment of various cancers, causes a cumulative dose-dependent cardiotoxicity that is characterized by an irreversible dilated cardiomyopathy and congestive heart failure. Antarth (ANT) a polyherbal preparation was evaluated for its cardioprotective properties against doxorubicin-induced cardiotoxicity in mice. Mice were treated with 25 mg/kg ANT orally once daily for 5 consecutive days before a single intraperitoneal injection of 15 mg/kg doxorubicin. The animals were killed 30 h after DOX treatment. DOX induced a significant elevation in the serum levels of glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), creatine kinase (CK-MB) and lactate dehydrogenase (LDH), indicating its acute cardiotoxicity. The treatment of mice with ANT before DOX administration significantly reduced the serum levels of GPT, GOT, CK-MB and LDH indicating that ANT protected against the DOX-induced cardiotoxicity. Pretreatment of mice with 25 mg/kg ANT inhibited the DOX-induced decline in the antioxidant status. Intraperitoneal injection of 1.25 mg/kg DOX once daily for 9 consecutive days significantly improved the survival of mice bearing Ehrlich ascites carcinoma (EAC). Treatment of EAC with 25 mg/kg ANT alone did not affect the anticancer activity of DOX since ANT did not alter the tumor cell growth, the median survival time and average survival time of tumor bearing mice. The present study demonstrates that ANT protects mice against DOX-induced cardiotoxicity, without compromising the antineoplastic activity of DOX.

Oral administration of a turmeric extract inhibits erythrocyte and liver microsome membrane oxidation in rabbits fed with an atherogenic diet

OBJECTIVES

The aim of this study was to evaluate the effects of an oral supplementation with a Curcuma longa ethanol and aqueous extract on the susceptibility to oxidation of cellular and subcellular membranes affected in the atherosclerotic process, such as erythrocyte membranes and liver microsomes, in rabbits fed with a high-fat diet.

METHODS

Twenty-four male rabbits were randomly assigned to one of two groups: group T was treated with a turmeric hydroalcoholic extract (1.66 mg/kg of body weight) dissolved in a hydroalcoholic mixture vehicle (7:2), and group C (control): received a curcuma-free hydroalcoholic solution (7:2). All rabbits had access ad libitum to 150 g/d of an experimental diet rich in cholesterol and lard to provoke an atherosclerotic process. Erythrocyte membranes and liver microsomes were isolated, and the levels of hydroperoxides and thiobarbituric acid-reactive substances were measured after oxidation induction.

RESULTS

The oxidation of erythrocyte membranes in group T was significantly lower than that in group C, mainly by 30 d (P < 0.05). Levels of hydroperoxides and thiobarbituric acid-reactive substances in liver microsomes also were significantly lower in group T than in group C (P < 0.05).

CONCLUSIONS

The results of this study indicated that oral administration of a nutritional dose of C. longa extracts reduces the susceptibility to oxidation of erythrocyte and liver microsome membranes in vitro and may contribute to the prevention of effects caused by a diet high in fat and cholesterol in blood and liver during the development of atherosclerosis.

Curcuma longa extract supplementation reduces oxidative stress and attenuates aortic fatty streak development in rabbits

OBJECTIVE

This study evaluates the effect of a Curcuma longa extract on the development of experimental atherosclerosis (fatty streak) in rabbits and its interaction with other plasmatic antioxidants.

METHODS AND RESULTS

Two experimental groups of male New Zealand White rabbits, a control group and a curcuma-extract (CU) group, were fed an atherogenic diet. Additionally, the CU group received an oral curcuma hydroalcoholic extract. Six animals from each experimental group were killed after 10, 20, and 30 days. Compared with the CU group, the control group showed significantly higher plasma lipid peroxide at all experimental times (10, 20, and 30 days) and significantly lower alpha-tocopherol and coenzyme Q levels at 20 and 30 days. Histological results for the fatty streak lesions revealed damage in the thoracic and abdominal aorta that was significantly lower in the CU group than in the control group at 30 days.

CONCLUSIONS

Supplementation with Curcuma longa reduces oxidative stress and attenuates the development of fatty streaks in rabbits fed a high cholesterol diet.

Dietary curcuminoids prevent high-fat diet-induced lipid accumulation in rat liver and epididymal adipose tissue

Curcumin and its structurally related compounds (curcuminoids), the phenolic yellowish pigments of turmeric, display antioxidative, anticarcinogenic and hypocholesterolemic activities. In this study, we investigated the effects of dietary supplemented curcuminoids [commercial grade curcumin: a mixture of curcumin (73.4%), demethoxycurcumin (16.1%) and bisdemethoxycurcumin (10.5%)] on lipid metabolism in rats. Male Sprague-Dawley rats were assigned to three diet groups (n = 6) and fed a moderately high-fat diet (15 g soybean oil/100 g diet) for 2 wk. One diet group did not receive supplements (CONT), while the others were supplemented with 0.2 g curcuminoids/100 g diet (CUR0.2) or 1.0 g curcuminoids/100 g diet (CUR1.0). Liver triacylglycerol and cholesterol concentrations were significantly lower in CUR1.0 rats than in CONT rats. Plasma triacylglycerols in the VLDL fraction were also lower in CUR1.0 rats than in CONT rats (P < 0.05). Hepatic acyl-CoA oxidase activity of both the CUR0.2 and CUR1.0 rats was significantly higher than that of CONT rats. Furthermore, epididymal adipose tissue weight was significantly reduced with curcuminoid intake in a dose-dependent manner. These results indicate that dietary curcuminoids have lipid-lowering potency in vivo, probably due to alterations in fatty acid metabolism.