Protection of N‐methyl‐N′‐nitro‐N‐nitrosoguanidine‐induced in vivo clastogenicity by aqueous garlic extract

Arivazhagan, S.; Nagini, Siddavaram; Santhiya, S.; Ramesh, A.

doi:10.1046/j.1440-6047.2001.00249.x

Cited by 11 publications

(6 citation statements)

References 25 publications

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“…However, dietary garlic supplementation was reported to reduce MNU-induced methylation of DNA in rat mammary gland (32). Treatment of rats with an aqueous garlic extract was also found to reduce N-methyl-N′-nitro-N-nitrosoguanidine (MNNG)-induced clastogenicity in bone marrow (33). The reason for these opposite findings in studies using direct-acting compounds is unclear.…”

Section: Discussionmentioning

confidence: 99%

Inhibition of Carcinogen-Induced DNA Damage in Rat Liver and Colon by Garlic Powders With Varying Alliin Content

Singh¹,

Belloir²,

Siess³

et al. 2006

Nutrition and Cancer

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The present study was designed to investigate the protective efficiency of three garlic powders, obtained from bulbs grown in soils with different levels of sulfur fertilization, against DNA damage. Increasing fertilization of soil resulted in an increased alliin content of the powders. Garlic powders were administered to rats for 2 weeks (5% of the diet) and their antigenotoxic effects were examined in the liver and the colon using the comet assay. Consumption of the different garlic powders induced a 35-60% reduction in DNA damage induced by N-nitrosodimethylamine (NDMA) in rat liver. Increased alliin content of the garlic powder was associated strongly with a proportional decrease in NDMA induced DNA alteration. DNA damage induced by aflatoxin B1 in the liver or by 1,2-dimethylhydrazine in the colon were also decreased strongly by the three garlic powders but these decreases were not correlated to the alliin content of the garlic powders. Feeding garlic powders did not modify the genotoxic activity of the direct-acting carcinogen methylnitrosourea in the colon. Part of our results supports evidence that fertilization can have an impact on the protective capacity of garlic bulbs.

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Section: Discussionmentioning

confidence: 99%

Inhibition of Carcinogen-Induced DNA Damage in Rat Liver and Colon by Garlic Powders With Varying Alliin Content

Singh¹,

Belloir²,

Siess³

et al. 2006

Nutrition and Cancer

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“…Lavelli et al (1999) reported that both fresh and air dried tomato extracts as well as processed tomatoes function as free radical scavengers in ROS-mediated reactions and in lipid peroxidation. Studies in this laboratory have demonstrated that tomato and garlic protect against the genotoxic effects of carcinogens by modulating lipid peroxidation and enhancing GSH-dependent antioxidants (Arivazhagan et al, 2000(Arivazhagan et al, , 2001b.…”

Section: Discussionmentioning

confidence: 99%

Attenuation of N-methyl-N′-nitro-N-nitrosoguanidine induced genotoxicity and oxidative stress by tomato and garlic combination

et al. 2005

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“…These compounds have also been shown to reduce the incidence of a multitude of chemically induced tumors in animal models. Pretreatment with aqueous garlic extract significantly reduced the frequencies of N-methyl-N 0 -nitro-N-nitrosoguanidine-induced micronuclei and chromosomal aberrations (Arivazhagan et al, 2001). These compounds have also been shown to reduce toxicity induced by thioacetamide, carbon tetrachloride, N-nitrosodimethylamine-and acetaminophen (all CYP2E1 substrates) in rodents (Ramaiah et al, 2001;Wang et al, 2000;.…”

Section: B Association Of Herb -Cyp Interactions With Chemoprotectivmentioning

confidence: 96%

Interactions of Herbs with Cytochrome P450

Zhou

Gao²,

Jiang

et al. 2003

Drug Metabolism Reviews

358

207

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A resurgence in the use of medical herbs in the Western world, and the co-use of modern and traditional therapies is becoming more common. Thus there is the potential for both pharmacokinetic and pharmacodynamic herb-drug interactions. For example, systems such as the cytochrome P450 (CYP) may be particularly vulnerable to modulation by the multiple active constituents of herbs, as it is well known that the CYPs are subject to induction and inhibition by exposure to a wide variety of xenobiotics. Using in vitro, in silico, and in vivo approaches, many herbs and natural compounds isolated from herbs have been identified as substrates, inhibitors, and/or inducers of various CYP enzymes. For example, St. John's wort is a potent inducer of CYP3A4, which is mediated by activating the orphan pregnane X receptor. It also contains ingredients that inhibit CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4. Many other common medicinal herbs also exhibited inducing or inhibiting effects on the CYP system, with the latter being competitive, noncompetitive, or mechanism-based. It appears that the regulation of CYPs by herbal products is complex, depending on the herb type, their administration dose and route, the target organ and species. Due to the difficulties in identifying the active constituents responsible for the modulation of CYP enzymes, prediction of herb -drug metabolic interactions is difficult. However, herb-CYP interactions may have important clinical and toxicological consequences. For example, induction of CYP3A4 by St. John's wort may partly provide an explanation for the enhanced plasma clearance of a number of drugs, such as cyclosporine and innadivir, which are known substrates of CYP3A4, although other mechanisms including modulation of gastric absorption and drug transporters cannot be ruled out. In contrast, many organosulfur compounds, such as diallyl sulfide from garlic, are potent inhibitors of CYP2E1; this may provide an explanation for garlic's chemoproventive effects, as many mutagens require activation by CYP2E1. Therefore, known or potential herb -CYP interactions exist, and further studies on their clinical and toxicological roles are warranted. Given that increasing numbers of people are exposed to a number of herbal preparations that contain many constituents with potential of CYP modulation, high-throughput screening assays should be developed to explore herb-CYP interactions.Key Words: Herb; Cytochrome P450; Drug interactions.Abbreviations: Ah, aryl hydrocarbon; AUC, the area of the plasma concentrationtime curve; B[a]P, benzo[a]pyrene; C max , the maximum plasma concentration; CL int , intrinsic clearance; CYP, cytochrome P450; DAD, diallyl disulfide; DAS, diallyl sulfide; DASO, diallyl sulfoxide; DASO 2 , diallyl sulfone; DPS, dipropyl sulfide; DPDS, dipropyl disulfide; K i , inhibition constant; K m , Michaelis -Menten constant; NADPH, nicotinamide adenine dinucleotide phosphate; NNK, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone; N-PiP, N-nitrosopiperidine; PgP, P-glycoprotein; PhIP...

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Protection of N‐methyl‐N′‐nitro‐N‐nitrosoguanidine‐induced in vivo clastogenicity by aqueous garlic extract

Cited by 11 publications

References 25 publications

Inhibition of Carcinogen-Induced DNA Damage in Rat Liver and Colon by Garlic Powders With Varying Alliin Content

Inhibition of Carcinogen-Induced DNA Damage in Rat Liver and Colon by Garlic Powders With Varying Alliin Content

Attenuation of N-methyl-N′-nitro-N-nitrosoguanidine induced genotoxicity and oxidative stress by tomato and garlic combination

Interactions of Herbs with Cytochrome P450

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