Anti-carcinogenic properties of curcumin on colorectal cancer

Curcumin has been used in traditional Indian medicine for many centuries for its anti-inflammatory and anticarcinogenic properties.There has been some promising research concerning curcumin as a safe therapeutic agent for many cancers,colorectal cancer being among them.This has been shown through research in cell cultures,animal models,and humans.At this time,it appears that curcumin’s anti-carcinogenic properties are most likely due to its effects on multiple molecular targets,such as nuclear factorκ-light-chain-enhancer of activated B cells(NF-κB)and activator protein 1(AP-1).NF-κB and AP-1 are both major transcription factors that regulate inflammation and thus affect cell proliferation,differentiation and even apoptosis.Curcumin has also been shown to affect a variety of other key players involved in carcinogenesis,such as cyclooxygenase-2,matrix metallopeptidases 2 and 9 and tumor necrosis factorαinduced vascular cell adhesion molecule,just to name a few.Although many molecular targets are involved,curcumin has been well tolerated in many studies:doses up to 8 g a day have been confirmed to be safe for humans.In this brief review,we will examine the current studies and literature and touch upon many molecular pathways affected by curcumin,and demonstrate the exciting possibility of curcumin as a chemopreventive agent for colorectal cancer.

The Antimutagenic and Anticarcinogenic Effects of Tea, Garllc and Other Natural Foods in China: A Review

It is well known that there are huge geographic variations in cancer rates in China's Mainland. For example, The National Cancer Control Office of the Ministry of Public Health (1979) reported that in the 1970s, cancer mortality rates for most cancers were found to be more than 20-fold greater in some counties in others (Table 1). Esophageal cancer rates for males are a few hundred fold greater in the highest county when compared with the lowest county. The mortality rate for all cancers combined for males is 21 fold greater in the county with the highest mortality than in the county with the lowest rate.According to Doll and Peto (1981), about one third of human cancer death is avoidable by appropriate modification of the diet. Therefore, diet is very likely to have an important part in causing these huge geographic variations. The possible role of various mutagens and carcinogens (e.g. afiatoxin, N-nitroso compounds) in locally produced and consumed foods has been strongly suggested and widely acknowledged, although much more evidence would be required to confirm their actual functions in human cancer. On the other hand, there are a few reports stating that the human diet also contains powerful antimutagens and anticarcinogens (Ames, 1983). The possible role of these two types of substances in causing the huge geographic variation of cancer risks remains elusive and inadequately explored. In order to make better use of these natural anticarcinogens in cancer prevention, it is important to elucidate their effects and mechanisms. The purpose of this paper is to summarize the available information on the antimutagenic and anticarcinogenic effects of natural foods in the Chinese diet, excluding the effects of essential nutrients, e.g. dietary fibers, vitamins and minerals. Most of the literature cited in this review was published by Chinese scientists.

Facile Synthetic Design and Characterization of Curcumin-Metformin Adduct： Potential Insights into the Role of This Conjugate in Diseases of Aging

Recently, the anti-glycation and anticancer properties of curcumin longa and okra seed extract were studied alone and also in combination with the well-established drug metformin. The combined effect of curcumin with metformin and metformin with okra seed extract was found to be highly efficacious in inhibiting Advanced Glycation End-products （AGEs）. In order to understand the mechanistic implications of curcumin combined with metformin and its enhanced anti-glycation activity, a Curcumin-Metformin Adduct was chemically synthesized. This adduct was fully characterized by thin-layer chromatography, Nano Drop spectrophotometry and electrospray-ionization mass spectrometry. The adduct may be helpful not only in elucidating the mechanism of anti-glycation and anti-cancer activities but also in studying the role of curcumin in binding of AI3-oligomers and disaggregating fibrillar formation in Alzheimer＇s disease.

Effects of Black Tea Extract on Transplantable and Solid Tumors in Swiss Albino Mice

The chemopreventive effects of green tea and its polyphenols are well documented in the literature. Epidemiological studies have suggested that green tea consumption might be effective in the prevention of certain human cancers. About 80% of the tea is consumed as black tea. Limited studies have been carried out to assess the usefulness of black tea as anti_carcinogen. The present set of investigations were initiated to study the anti_tumorigenic potential of aqueous black tea extract (ATE) in Swiss albino mice in \%in vivo\% animal bioassay, using 7, 12 dimethyl_benzanthracene (DMBA) as carcinogen. In the experimental group, 2% ATE was given orally as sole source of drinking water, while the control were allowed to drink normal water, \%ad lib.\% The results revealed that drinking of 2% ATE could effectively inhibit the onset of tumorigenesis, cumulative number of tumors and average number of tumors per mouse. In ATE drinking group 44% animals remained tumor free till the termination of experiment, i. e. 26 weeks. In the second set of experiment the preventive efficacy of 2% ATE of different cultivars of black tea, viz orthodox, CTC and dust were tested in Ehrlich Ascites (EA) tumor bearing mice. The preventive effects of ATE were observed in terms of increased life span (ILS). All the cultivars of tea showed more than 25% increase in life span of the animals. Cytotoxic effect of various doses of all three cultivars of black tea was also observed \%in vitro \%on EA cells.

Health promoting activities and corresponding mechanism of(–)-epicatechin-3-gallate

(–)-Epicatechin-3-gallate(ECG),a bioactive polyphenolic compound,has contributed a lot to the health benefits of green tea.Great attention has been focused on(–)-epigallocatechin-3-gallate(EGCG),but limited research has been performed towards ECG.Like EGCG,ECG also possesses various pharmacological and physiological properties,such as mediation of antioxidant activities,anti-inflammation response,regulation of cell proliferation and apoptosis,as well as anticancer properties during angiogenesis,invasion and metastasis stages.Nontoxic ECG has various molecular targets within the cells,including CYP enzymes,phaseⅡdetoxification and antioxidant enzymes,as well as pro-inflammatory mediators.The antineoplastic mechanism contains inhibition of phase 1 CYP enzymes,induction of phaseⅡdetoxification and antioxidant enzymes,high anti-inflammatory efficacy,arrest of cell cycle progression,regulation of apoptosis,as well as mediation of metastasis processes.In particular,the gallate moiety of ECG is critical for mediating inhibitory effects towards cancer cells.Besides regulation of intracellular signaling pathways,ECG also inhibits RNase A and matrix metalloproteinase enzymatic activity via chelating metals(copper and zinc)in cancer cells.This review has summarized recent studies on pharmacological properties of ECG,and discussed corresponding mechanism on modulation of cellular signaling events by ECG,hoping to broaden its multiple usage.

Anti-Cancer Effects and Mechanisms of Capsaicin in Chili Peppers

Cancer is a major cause of morbidity and mortality all over the world and a promising area of cancer research is concentrated on chemoprevention by nutritional compounds. Capsaicin, traditionally used as a food additive and an analgesic, is one of the main pungent ingredients in chili peppers. Recent studies have shown that capsaicin has anti-cancer effects in various types of cancer model. The purpose of this review is to outline the anticarcinogenic effect of capsaicin and its mechanism.

Gallic Acid Isolated from Pomegranate Peel Extract Induces Reactive Oxygen Species Mediated Apoptosis in A549 Cell Line

Antioxidant properties elicited by plant species have a full range of perspective applications in human health care. In recent years, the prevention of cancer and cardiovascular diseases has been associated with the ingestion of fresh fruits, vegetables or teas rich in natural antioxidants [1]. Extracts from the different part of the pomegranate plant such as juice, seed and peel have been reported to exhibit a potent antioxidant activity. But the anticarcinogenic activity of active principle from the pomegranate peel extract was not studied so far. Hence the present study was planned to explore the molecular mechanism of the anticarcinogenic activity pomegranate peel on A549 cell line. In this study, GC-MS analysis was carried out for the methanolic extract of pomegranate peel which revealed gallic acid (GA) as the major antioxidant compound in the extract. Hence GA was purified further through RP-HPLC and evaluated its anticancer potential by studying its effect on mitochondrial respiration, cell-membrane integrity, apoptotic body formation and the DNA fragmentation in cultured A549 cells. We observed increased level of reactive oxygen species in the cells treated with GA at the concentrations of 10 and 20 ug/ml. Further analysis of caspase activation (caspase 8 and 9) revealed activation of caspases 9 in the cells treated with GA at a concentration of 20 ug/ml. Thus the present study revealed that the GA isolated from the pomegranate peel extract (Kabul variety) induced apoptosis in A549 cells through intrinsic pathway.

The effect of folic acid on the development of stomach and other gastrointestinal cancers

OBJECTIVE: To evaluate the roles of folic acid and beta-carotene in the chemoprevention of gastric and other gastrointestinal (GI) cancers. METHODS: In a randomized, double-blind, placebo-controlled trial, a total of 216 patients with atrophic gastritis were randomly assigned to one of the four groups: (1) folate (FA, 20 mg per day plus vitamin B(12) 1 mg, intramuscularly, per month for one year, then 20 mg two times a week plus 1 mg per three months for the next year); (2) natural beta-carotene (N-betaC, 30 mg per day for first year, then 30 mg two times a week for the next); (3) synthetic beta-carotene (S-betaC, administered as in N-betaC); and (4) placebo. Follow-ups continued from 1994 to 2001. RESULTS: A total of 7 new cases of gastrointestinal cancers were diagnosed with 3 stomach, 1 colon and 1 esophageal cancers occurring in the placebo group; 1 stomach cancer in both of the N-betaC and S-betaC groups, and no cancer occurring in FA group. In terms of GI cancers, there was a significant reduction in the FA group, compared with the placebo group (P = 0.04). A similar trend was observed in both N-betaC and S-betaC groups (P = 0.07 - 0.08). Taken together, the three intervention groups displayed a highly significant decrease in occurrence (P = 0.004, vs placebo), and a lower risk for GI cancers (OR = 0.12; 95% confidence interval, 0.03 - 0.51). For development of gastric cancer, any one of the three active-treated groups did not reach statistically significant reduction. The FA group showed obvious improvement of the gastric mucosal lesions with more patients displaying lesions reversed or stable atrophy and inflammation (P = 0.04), reversed intestinal metaplasia (P = 0.06) at the end of follow-up, and reversed displasia (P = 0.017) at 12 months. Two cases of false jaundice were found in beta-carotene groups with no influence on administration, and no side-effects were reported in FA group. CONCLUSIONS: This trial revealed the interventional effect of folic acid on the development of GI cancers, a similar effect of beta-carotene was also detected. Also, folic acid may be of use to treat atrophic gastritis by preventing or reversing the precancerous lesions.