Suppression of altered hepatic foci development by curcumin in wistar rats

The therapeutic potential of curcumin in alleviating N-diethylnitrosamine and iron nitrilotriacetate induced renal cell tumours in mice via inhibition of oxidative stress: Implications for cancer chemoprevention

This study was designed to reveal the protective effects of dietary supplementation of curcumin against renal cell tumours and oxidative stress induced by renal carcinogen iron nitrilotriacetate (Fe-NTA) in ddY male mice. The results showed that mice treated with a renal carcinogen, Fe-NTA, a 35% renal cell tumour incidence was noticed, whereas renal cell tumour occurrence was elevated to 80% in Fe-NTA promoted and N-diethylnitrosamine (DEN)-initiated mice as compared with saline- treated mice. No incidence of tumours has been observed in DEN-initiated non-promoted mice. Diet complemented with 0.5% and 1.0% curcumin fed prior to, during and after treatment with Fe-NTA in DEN-initiated animals, tumour incidence was reduced dose-dependently to about 45% and 30% respectively. Immunohistochemical studies also revealed the increased formation of 4-hydroxy-2-nonenal (HNE)-modified protein adducts and 8-hydroxy-2'-deoxyguanosine (8-OHdG) in kidney tissue of mice treated with an intraperitoneal injection of Fe-NTA (6.0 mg Fe/kg body weight.). Furthermore, Fe-NTA treatment of mice also resulted in significant elevation of malondialdehyde (MDA), serum urea, and creatinine and decreases renal glutathione. However, the changes in most of these parameters were attenuated dose-dependently by prophylactic treatment of animals with 0.5% and 1% curcumin diet, this may be due to its antioxidative impact of curcumin. These results suggest that intake of curcumin is beneficial for the prevention of renal cell tumours and oxidative stress damage mediated by renal carcinogen, Fe-NTA.

Focus on Multi-targeted Role of Curcumin: a Boon in Therapeutic Paradigm

Curcumin is a polyphenolic compound that exhibited good anticancer potential against different types of cancers through its multi-targeted effect like the termination of cell proliferation, inflammation, angiogenesis, and metastasis, thereby acting as antiproliferative and cytotoxic in nature. The present review surveys the various drug combination tried with curcumin or its synthetic analogues and also the mechanism by which curcumin potentiates the effect of almost every drug. In addition, this article also focuses on aromatherapy which is gaining much popularity in cancer patients. After thoroughly studying several articles on combination therapy of curcumin through authenticated book chapters, websites, research, and review articles available at PubMed, ScienceDirect, etc., it has been observed that multi-targeted curcumin possess enormous anticancer potential and, with whatever drug it is given in combination, has always resulted in enhanced effect with reduced dose as well as side effects. It is also capable enough in overcoming the problem of chemoresistance. Besides this, aromatherapy also proved its potency in reducing cancer-related side effects. Combining all the factors together, we can conclude that combination therapy of drugs with curcumin should be explored extensively. In addition, aromatherapy can be used as an adjuvant or supplementary therapy to reduce the cancer complications in patients.

The role of polyphenols in poultry nutrition

In the last two decades, poultry and animal industries became increasingly interested in using plant-based feed supplements, herbs and their derivatives to retain or enhance their health and productivity. These health benefits for the host mainly attributed to the secondary plant metabolites, namely polyphenols. Polyphenols are renowned for their antioxidant, immunomodulatory, anti-mutagenic and anti-inflammatory properties. However, despite these advantages of polyphenols, they have been characterized by poor absorption in the gut and low concentration in target cells that compromise their role as effective antioxidants. The low bioavailability of polyphenols necessitates the need for further investigations to harness their full potential in poultry farms. This review is existing evidence about the bioavailability of polyphenols and their antioxidant, immunomodulatory, antimicrobial, detoxification properties and their impacts on poultry performance.

Induction of preneoplastic altered hepatic foci following dietary sulphur supplementation

Sulphur is an essential micronutrient required by the body in low concentrations, but its high intake can lead to a serious health hazard. Sulphur compounds are reported to induce several toxic responses in animals, but so far no reports are available on the toxic effects of elemental sulphur, following dietary supplementation. The present investigation was carried out with the aim of providing an insight into the role of dietary supplementation of sulphur on the induction of altered hepatic foci (AHF) using medium term liver bioassay in Wistar rats. Induction of AHF are early neoplastic changes in rat liver in diethylnitrosamine (DEN)-initiated and 2-acetylamino fluorene (2-AAF)-promoted hepatocarcinogenesis. The role of sulphur on induction of AHF was evaluated by the development of negative enzymatic foci for alkaline phosphatase (AlkPase), adenosine triphosphatase (ATPase), glucose-6-phosphatase (G-6-Pase) and positive foci for marker enzymes, glutamyl transferase (GGT), placental isozyme of glutathione-S transferase (GST-P). A significant dose-dependent decrease in the relative and absolute liver weight of sulphur-administered rats was recorded. Dietary supplementation of 2% and 4% sulphur significantly induces both negative and positive focal areas in terms of area and counts for AHF. However, 1% sulphur administration failed to induce AHF up to significant levels. The results thus revealed the possible tumorigenic risk associated with the high sulphur-containing diet.

Chemoprevention against hepatocellular carcinoma

Since the majority of hepatocellular carcinoma (HCC) arises from a background of chronic liver diseases caused by infection with hepatitis C virus (HCV) and hepatitis B virus (HBV), chemoprevention targeting patients at high risk of HCC is feasible. In this review article, we summarize current knowledge of chemoprevention against HCC mostly using phytochemicals which have less toxicity than pharmaceutical agents. We describe in vivo and in vitro evidence and proposed mechanisms of beneficial effects of several compounds on the liver, including acyclic retinoid (ACR), angiotensin-converting enzyme inhibitors (ACEIs), caffeine, capsaicin, cepharanthine (CEP), cinnamaldehyde, curcumin, diallyl sulfide (DAS), eicosapentaenoic acid (EPA), epigallocatechin-3-gallate (EGCG), genistein, lycopene, resveratrol, silymarin, sulforaphane (SFN), and xanthohumol (XN). Because antihepatocarcinogenic effects by these compounds are mostly based on experimental studies, clinical evidence is urgently necessary.

Dietary antioxidants in the prevention of hepatocarcinogenesis: a review

In this review, the role of dietary antioxidants in the prevention of hepatocarcinogenesis is examined. Both human and animal models are discussed. Vitamin C, vitamin E, and selenium are antioxidants that are essential in the human diet. A number of non-essential chemicals also contain antioxidant activity and are consumed in the human diet, mainly as plants or as supplements, including beta-carotene, ellagic acid, curcumin, lycopene, coenzyme Q(10), epigallocatechin gallate, N-acetyl cysteine, and resveratrol. Although some human and animal studies show protection against carcinogenesis with the consumption of higher amounts of antioxidants, many studies show no effect or an enhancement of carcinogenesis. Because of the conflicting results from these studies, it is difficult to make dietary recommendations as to whether consuming higher amounts of specific antioxidants will decrease the risk of developing hepatocellular carcinoma.

Phytochemicals as potential chemopreventive and chemotherapeutic agents in hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is the fifth commonest malignancy worldwide and the incidence is rising. Surgery, including transplantation resection, is currently the most effective treatment for HCC; however, recurrence rates are high and long-term survival is poor. Identifying novel chemopreventive and chemotherapeutic agents and targeting them to patients at high risk of developing HCC or following curative treatment may go some way towards improving prognosis. This review examines current knowledge regarding the chemopreventive and chemotherapeutic potential of phytochemicals in heptocarcinogenesis. Both in-vitro and animal studies demonstrate that several phytochemicals, including curcumin, resveratrol, green tea catechins, oltipraz and silibinin, possess promising chemopreventive and chemotherapeutic properties. Despite this, very few clinical trials have been performed. Problems regarding validation of biomarkers, agent delivery, side effects and patient selection are barriers that need to be overcome to determine the potential of such agents in clinical practice.

Anticancer and carcinogenic properties of curcumin: considerations for its clinical development as a cancer chemopreventive and chemotherapeutic agent

A growing body of research suggests that curcumin, the major active constituent of the dietary spice turmeric, has potential for the prevention and therapy of cancer. Preclinical data have shown that curcumin can both inhibit the formation of tumors in animal models of carcinogenesis and act on a variety of molecular targets involved in cancer development. In vitro studies have demonstrated that curcumin is an efficient inducer of apoptosis and some degree of selectivity for cancer cells has been observed. Clinical trials have revealed that curcumin is well tolerated and may produce antitumor effects in people with precancerous lesions or who are at a high risk for developing cancer. This seems to indicate that curcumin is a pharmacologically safe agent that may be used in cancer chemoprevention and therapy. Both in vitro and in vivo studies have shown, however, that curcumin may produce toxic and carcinogenic effects under specific conditions. Curcumin may also alter the effectiveness of radiotherapy and chemotherapy. This review article analyzes the in vitro and in vivo cancer-related activities of curcumin and discusses that they are linked to its known antioxidant and pro-oxidant properties. Several considerations that may help develop curcumin as an anticancer agent are also discussed.

Bioavailability issues in studying the health effects of plant polyphenolic compounds

Polyphenolic compounds are common in the diet and have been suggested to have a number of beneficial health effects including prevention of cancer, cardiovascular disease, diabetes, and others. For some dietary polyphenols, certain benficial effects are suggested by epidemiological studies, some are supported by studies in animal models, and still others are extrapolated from studies in vitro. Because of the relatively poor bioavailability of many of these compounds, the molecular basis of these beneficial effects is not clear. In the present review, we discuss the potential health benefits of dietary polyphenols from the point of view of bioavailability. Tea catechins, curcumin, and proanthocyanidins are used as examples to illustrate some of the problems that need to be resolved. Further research on both the biological activity and bioavailability of dietary polyphenols is needed to properly assess their usefulness for the prevention and treatment of disease.

Effect of antioxidant phytochemicals on the hepatic tumor promoting activity of 3,3',4,4'-tetrachlorobiphenyl (PCB-77)

Polychlorinated biphenyls (PCBs) have promoting activity in the liver, which may be brought about in part by the induction of oxidative stress. In this study we examined the effects of several antioxidant phytochemicals on the tumor promoting activity of 3,3',4'4-tetrachlorobiphenyl (PCB-77). Female Sprague Dawley rats were first injected with diethylnitrosamine (DEN, 150 mg/kg) and one week later the rats were fed an AIN-93 based purified diet or the same diet containing ellagic acid (0.4%), beta-carotene (0.5%), curcumin (0.5%), N-acetyl cysteine (NAC, 1.0%), coenzyme CoQ10 (CoQ10, 0.4%), resveratrol (0.005%), lycopene (10% as Lycovit, which contains 10% lycopene), or a tea extract (1%, containing 16.5% epigallocatechin-3-gallate [EGCG] and 33.4% total catechins). Rats were fed the diets for the remainder of the study. After three weeks, 2/3 of the control rats and all of the antioxidant diet-fed rats were injected i.p. with PCB-77 (300 micromol/kg) every other week for four injections. All rats were euthanized ten days after the last PCB injection. The rats that received PCB-77 alone showed an increase in the number and size of placental glutathione S-transferase (PGST)-positive foci in the liver. Lycopene significantly decreased the number of foci, while curcumin and CoQ10 decreased the size of the foci. In contrast, ellagic acid increased the number but decreased the size of the foci. All of the other phytochemicals showed only slight or no effects. Compared with the PCB-77 group, CoQ10 increased cell proliferation in normal hepatocytes, whereas the other antioxidants had no effect in either normal or PGST-positive hepatocytes. These findings show that none of the antioxidant phytochemicals produced a clear decrease in the promoting activity of PCB-77.

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".

Ethnoveterinary medicines used for ruminants in British Columbia, Canada

BACKGROUND

The use of medicinal plants is an option for livestock farmers who are not allowed to use allopathic drugs under certified organic programs or cannot afford to use allopathic drugs for minor health problems of livestock.

METHODS

In 2003 we conducted semi-structured interviews with 60 participants obtained using a purposive sample. Medicinal plants are used to treat a range of conditions. A draft manual prepared from the data was then evaluated by participants at a participatory workshop.

RESULTS

There are 128 plants used for ruminant health and diets, representing several plant families. The following plants are used for abscesses: Berberis aquifolium/Mahonia aquifolium Echinacea purpurea, Symphytum officinale, Bovista pila, Bovista plumbea, Achillea millefolium and Usnea longissima. Curcuma longa L., Salix scouleriana and Salix lucida are used for caprine arthritis and caprine arthritis encephalitis. Euphrasia officinalis and Matricaria chamomilla are used for eye problems. Wounds and injuries are treated with Bovista spp., Usnea longissima, Calendula officinalis, Arnica sp., Malva sp., Prunella vulgaris, Echinacea purpurea, Berberis aquifolium/Mahonia aquifolium, Achillea millefolium, Capsella bursa-pastoris, Hypericum perforatum, Lavandula officinalis, Symphytum officinale and Curcuma longa. Syzygium aromaticum and Pseudotsuga menziesii are used for coccidiosis. The following plants are used for diarrhea and scours: Plantago major, Calendula officinalis, Urtica dioica, Symphytum officinale, Pinus ponderosa, Potentilla pacifica, Althaea officinalis, Anethum graveolens, Salix alba and Ulmus fulva. Mastitis is treated with Achillea millefolium, Arctium lappa, Salix alba, Teucrium scorodonia and Galium aparine. Anethum graveolens and Rubus sp., are given for increased milk production. Taraxacum officinale, Zea mays, and Symphytum officinale are used for udder edema. Ketosis is treated with Gaultheria shallon, Vaccinium sp., and Symphytum officinale. Hedera helix and Alchemilla vulgaris are fed for retained placenta.

CONCLUSION

Some of the plants showing high levels of validity were Hedera helix for retained placenta and Euphrasia officinalis for eye problems. Plants with high validity for wounds and injuries included Hypericum perforatum, Malva parviflora and Prunella vulgaris. Treatments with high validity against endoparasites included those with Juniperus communis and Pinus ponderosa. Anxiety and pain are well treated with Melissa officinalis and Nepeta caesarea.

Chemopreventive and therapeutic effects of curcumin

Chemoprevention is a promising anti-cancer approach with reduced secondary effects in comparison to classical chemotherapy. Curcumin, one of the most studied chemopreventive agents, is a natural compound extracted from Curcuma longa L. that allows suppression, retardation or inversion of carcinogenesis. Curcumin is also described as an anti-tumoral, anti-oxidant and anti-inflammatory agent capable of inducing apoptosis in numerous cellular systems. In this review, we describe both properties and mode of action of curcumin on carcinogenesis, gene expression mechanisms and drug metabolism.

Chemopreventive Effect of Indole-3-Carbinol on Induction of Preneoplastic Altered Hepatic Foci

Indole-3-carbinol (I3C) is a cleavage product of glucobrassicanin, a natural compound present in a wide variety of plant food substances including members of the family Cruciferae. I3C is known to possess cancer-chemopreventive potential in various animal models. The present study reveals the protective effect of I3C on the development of diethylnitrosamine (DEN)-initiated and 2-acetylaminofluorene (AAF)-promoted preneoplastic, altered hepatic foci (AHF) in Wistar rats. I3C was given at dose levels of 0.5 and 1 mg/kg body weight for five consecutive days along with DEN and AAF. AHF were scored and analyzed by quantitative stereology using the Image Analysis System from frozen liver sections stained for positive and negative biological markers of AHF, that is, glutathione S-transferase (GST-P), gamma-glutamyl transpeptidase (GGT), glucose-6-phosphatase (G6Pase), adenosine triphosphatase (ATPase), and alkaline phosphatase (AlkPase). Results revealed the chemopreventive effect of I3C on the DEN-initiated AHF in Wistar rats. The expression of G6Pase, ATPase, and AlkPase was restored in the I3C-supplemented animal. Similarly the induced expression GST-P and GGT also decreased in the animals with I3C administration. The recovery of altered levels of these biomarkers was of comparatively higher magnitude in the animals given a higher dose of I3C (1 mg/kg body weight) in comparison with the animals given 0.5 mg/kg body weight dose of I3C, although no dose-dependence pattern was recorded in I3C-supplemented groups. These results thus suggest the chemopreventive effect of I3C in rat hepatocarcinogenesis by suppressing DEN- and AAF-induced AHF development.

Modulation of altered hepatic foci induction by diallyl sulphide in Wistar rats

Diallyl sulphide (DAS) is a sulphur-containing volatile compound present in garlic (Allium sativum). It has been shown to inhibit a number of chemically induced forms of cancer in experimental animals. The present study demonstrates the inhibitory effect of DAS on the development of diethylnitrosamine (DEN) initiated and 2-acetyl-aminofluorene (2-AAF) promoted preneoplastic altered hepatic foci (AHF) in Wistar rats. AHF were scored and analysed by quantitative stereology using the Image Analysis system from frozen liver sections stained for biological markers, namely glutathione S-transferase, placental form (GST-P), gamma-glutamyl transpeptidase (GGT), adenosine triphosphatase (ATPase), glucose-6-phosphatase (G6 Pase) and alkaline phosphatase (AlkPase). DAS-supplemented rats were found to restore the near-normal levels of enzymes GST-P and GGT when exposed to DEN and 2-AAF. DAS administration following DEN and 2-AAF exposure led to the restoration of enzymic activity of ATPase, G6 Pase and AlkPase, as evident by number and area of the foci. These findings suggest the protective role of DAS in rat hepatocarcinogenesis, by suppressing DEN- and 2-AAF-induced AHF development.