Protection of liver cells from ethanol cytotoxicity by curcumin in liver slice culture in vitro

Antimutagenic potential of curcumin on chromosomal aberrations in Allium cepa

Turmeric has long been used as a spice and food colouring agent in Asia. In the present investigation, the antimutagenic potential of curcumin was evaluated in Allium cepa root meristem cells. So far there is no report on the biological properties of curcumin in plant test systems. The root tip cells were treated with sodium azide at 200 and 300 microg/ml for 3 h and curcumin was given at 5, 10 and 20 microg/ml for 16 h, prior to sodium azide treatment. The tips were squashed after colchicine treatment and the cells were analyzed for chromosome aberration and mitotic index. Curcumin induces chromosomal aberration in Allium cepa root tip cells in an insignificant manner, when compared with untreated control. Sodium azide alone induces chromosomal aberrations significantly with increasing concentrations. The total number of aberrations was significantly reduced in root tip cells pretreated with curcumin. The study reveals that curcumin has antimutagenic potential against sodium azide induced chromosomal aberrations in Allium cepa root meristem cells. In addition, it showed mild cytotoxicity by reducing the percentage of mitotic index in all curcumin treated groups, but the mechanism of action remains unknown. The antimutagenic potential of curcumin is effective at 5 microg/ml in Allium cepa root meristem cells.

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".

Experimental approaches for studying uptake and action of herbal medicines

In order to gain wider credibility, herbal medicines must go through the rigorous scientific scrutiny to which synthetic drugs are subjected, and this includes investigating their absorption, bioavailability and metabolism. This review describes approaches for determining how active compounds in herbal formulations enter the systemic circulation. To assess how bioactive molecules enter the target organs and cells, specific cell lines and organ culture models can be used, followed by in vitro models to show how they may regulate digestion, energy balance and metabolism. This could lead to a better understanding of how herbal medicines affect digestion and absorption; fundamental questions which should be answered in addition to their mechanism of action.

Inhibition of oxidative stress and cytokine activity by curcumin in amelioration of endotoxin-induced experimental hepatoxicity in rodents

The present study is aimed at investigating the effect of curcumin (CMN) in salvaging endotoxin-induced hepatic dysfunction and oxidative stress in the liver of rodents. Hepatotoxicity was induced by administering lipopolysaccharide (LPS) in a single dose of 1 mg/kg intraperitoneally to the animals, which were being treated with CMN daily for 7 days. Liver enzymes serum alanine aminotransferase (ALT), serum aspartate aminotransferase (AST) and alkaline phosphatase (ALP), total bilirubin and total protein were estimated in serum. Oxidative stress in liver tissue homogenates was estimated by measuring thiobarbituric acid reactive substances (TBARS), glutathione (GSH) content and superoxide dismutase (SOD) activity. Serum and tissue nitrite was estimated using Greiss reagent and served as an indicator of NO production. A separate set of experiments was performed to estimate the effect of CMN on cytokine levels in mouse serum after LPS challenge. LPS induced a marked hepatic dysfunction evident by rise in serum levels of ALT, AST, ALP and total bilirubin (P < 0.05). TBARS levels were significantly increased, whereas GSH and SOD levels decreased in the liver homogenates of LPS-challenged rats. CMN administration attenuated these effects of LPS successfully. Further CMN treatment also regressed various structural changes induced by LPS in the livers of rats and decreased the levels of tumour necrosis factor-alpha and interleukin-6 in mouse plasma. In conclusion, these findings suggest that CMN attenuates LPS-induced hepatotoxicity possibly by preventing cytotoxic effects of NO, oxygen free radicals and cytokines.

Immediate and Delayed Treatments with Curcumin Prevents Forebrain Ischemia-Induced Neuronal Damage and Oxidative Insult in the Rat Hippocampus

Oxidative stress is believed to contribute to neurodegeneration following ischemic injury. The present study was undertaken to evaluate the possible antioxidant neuroprotective effect of curcumin (Cur) on neuronal death of hippocampal CA1 neurons following transient forebrain ischemia in rat. Treatment of Cur (200 mg/kg/day, i.p.) at three different times (immediately, 3 h and 24 h after ischemia) significantly (P<0.01) reduced neuronal damage 7 days after ischemia. Also, treatment of ischemic rats with Cur decreased the elevated levels of MDA and increased GSH contents, catalase and SOD activities to normal levels. In the in vitro, Cur was as potent as antioxidant (IC(50) = 1 microM) as butylated hydroxytoluene. The present study demonstrates that curcumin treatment attenuates forebrain ischemia-induced neuronal injury and oxidative stress in hippocampal tissue. Thus treatment with curcumin immediately or even delayed until 24 h may have the potential to be used as a protective agent in forebrain ischemic insult in human.

Effect of curcumin on the expression of LDL receptor in mouse macrophages

To investigate the molecular mechanisms of lipid-lowering drug, Rhizoma Curcumae Longae, we treated the mouse macrophages with curcumin, which was purified from the ethanol extraction of Rhizoma Curcumae Longae. The LDL receptors expressed in the macrophages were determined by ELISA, FLISA and assay of LDL uptake. Here for the first time, we found that curcumin obviously up-regulated the expression of LDL receptor in mouse macrophages, and the dose-effect relationship was demonstrated.

Dietary antioxidant compounds and liver health

Chronic liver damage is a widespread pathology characterized by a progressive evolution from steatosis to chronic hepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. As the oxidative stress plays a central role in liver diseases pathogenesis and progression, the use of antioxidants have been proposed as therapeutic agents, as well as drug coadjuvants, to counteract liver damage. In this work in vitro and in vivo studies, with emphasis on humans and animals experiments, have been considered and reviewed according to antioxidant typologies. Great differences emerge as far as ingested doses, bioavailability and liver ability to accumulate the various compounds. Results available up to now suggest that lycopene-rich foods could be proposed in therapeutic treatment of some liver pathologies. On the other hand contradictory results have been obtained with alpha-tocopherol, beta-carotene and trans-resveratrol. Quercetin, silymarin, esculetin and thyme and rosemary among phenolic compounds need further studies.