Rajarajeswaran Jayakumar

Dietary spices protect against hydrogen peroxide-induced DNA damage and inhibit nicotine-induced cancer cell migration

Spices are rich sources of antioxidants due to the presence of phenols and flavonoids. In this study, the DNA protecting activity and inhibition of nicotine-induced cancer cell migration of 9 spices were analysed. Murine fibroblasts (3T3-L1) and human breast cancer (MCF-7) cells were pre-treated with spice extracts and then exposed to H₂O₂ and nicotine. The comet assay was used to analyse the DNA damage. Among the 9 spices, ginger, at 50 μg/ml protected against 68% of DNA damage in 3T3-L1 cells. Caraway, cumin and fennel showed statistically significant (p<0.05) DNA protecting activity. Treatment of MCF-7 cells with nicotine induced cell migration, whereas pre-treatment with spices reduced this migration. Pepper, long pepper and ginger exhibited a high rate of inhibition of cell migration. The results of this study prove that spices protect DNA and inhibit cancer cell migration.

Synthesis of flexirubin-mediated silver nanoparticles using Chryseobacterium artocarpi CECT 8497 and investigation of its anticancer activity

In this work, the synthesis of silver nanoparticles from a pigment produced by a recently-discovered bacterium, Chryseobacterium artocarpi CECT 8497, was achieved, followed by an investigation of its anticancer properties. The bacterial pigment was identified as flexirubin following NMR ((1)H NMR and (13)C NMR), UV-Vis, and LC-MS analysis. An aqueous silver nitrate solution was treated with isolated flexirubin to produce silver nanoparticles. The synthesised silver nanoparticles were subsequently characterised by UV-Vis spectroscopy, Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDX), X-Ray Diffraction (XRD), and Fourier Transform Infrared (FTIR) Spectroscopy methodologies. Furthermore, the anticancer effects of synthesised silver nanoparticles in a human breast cancer cell line (MCF-7) were evaluated. The tests showed significant cytotoxicity activity of the silver nanoparticles in the cultured cells, with an IC50 value of 36μgmL(-1). This study demonstrates that silver nanoparticles, synthesised from flexirubin from C. artocarpi CECT 8497, may have potential as a novel chemotherapeutic agent.

Analysis of chemical composition and bioactive property evaluation of Indian propolis

OBJECTIVE To analyze the chemical composition and to evaluate the bioactive potential of hydroalocoholic extract of propolis. METHODS Ethanol extract of propolis was analyzed by GC-MS, HPTLC and HPLC methods and in vitro antioxidant, anticholinesterase and cytotoxicity assay were performed. RESULTS GC-MS analysis revealed the presence of fatty acids, alcohols, and quercetin. Quercetin was identified and quantified by HPTLC and HPLC methods. Dose dependent DPPH and hydroxyl radical scavenging activity of hydroalcoholic extract of propolis was calculated as 16.20 and 34.33 µg/mL respectively. Inhibition of lipid peroxidation was significant and the IC50 value was calculated as 55.56µg/mL. Anticholinesterase activity was less observed. The cytotoxic activity against both breast (MCF-7) and lung cancer (A543) cell lines were significant and the IC50 value was calculated as 10 and 13 µg/mL respectively. CONCLUSIONS These findings showed that bioactive compounds present in propolis will alleviate many diseases and can be used for better human health.

XRCC1 gene variants and possible links with chromosome aberrations and micronucleus in active and passive smokers

Tobacco addiction is a major risk for diseases such as cancers, heart attack, etc. Tobacco smoke constitutes environmental toxins that are the major preventable leading cause of death worldwide. We investigated the influence of tobacco smoke on cytogenetic parameters (chromosomal aberrations and micronuclei) and the influence of XRCC1 arg399gln polymorphism on the cytogenetic parameters of the exposed subjects. The cases for this study include active and passive smokers. They were divided into three groups in accordance with duration of exposure to tobacco smoke. We observed changes in the frequency of chromosomal aberrations and micronuclei among the exposed subjects and controls. Of the three groups of exposed subjects, group III of active smokers and group III of passive smokers showed higher number of chromosomal aberrations and micronuclei when compared to controls, group I and group II of active and passive smokers. The XRCC1 arg399gln polymorphic variant gln/gln, influenced the extent of genotoxic damage in chromosomes and frequency of in micronuclei the three variants (arg/arg, arg/gln and gln/gln), gln/gln harbored significantly (P<0.05) higher number of aberrations than the arg/arg and arg/gln. In this context, the results observed in our study indicated that the single nucleotide polymorphism on XRCC1codon 399 influenced the frequencies of chromosomal aberrations and micronuclei.

Assessment of genotoxic and molecular mechanisms of cancer risk in smoking and smokeless tobacco users.

Inexpensive forms of tobacco are widely used in developing countries such as India. We have evaluated genotoxicity endpoints (chromosome aberrations, micronucleus frequency, comet assay) and polymorphisms of the XRCC1 and p53 genes among smokers and smokeless tobacco (SLT) users in rural Tamilnadu, South India. Cytogenetic, DNA damage and SNP analyses were performed on peripheral blood samples; micronucleus frequency was measured in peripheral blood and buccal mucosa exfoliated cells. Both categories of tobacco users had elevated levels of genotoxic damage. SNP analysis of tobacco users revealed that 17% carry the XRCC1 gln399gln genotype and 19% carry the p53 pro72pro genotype. Both genotypes are associated with increased risk of cancer.

Antiacetylcholinesterase and antioxidant ent -Kaurene diterpenoid, melissoidesin from Isodon wightii (Bentham) H. Hara

The ent kaurene diterpenoid, melissoidesin was isolated from the acetone extract of the leaves of Isodon wightii and the structure was designated as 3β, 11β, 15β-trihydroxy-6α-acetoxy-ent-kaur-16-ene based on spectral data and previous reports. Melissoidesin isolated from the acetone extract of leaves showed potent antiacetylcholinesterase activity and the IC50 value was observed as 215 µg mL−1. DPPH (1, 1-diphenyl-2-picrylhydrazyl) free radical scavenging activity of melissoidesin was significant and the IC50 value was 138 µg mL−1. The significant reducing property of the melissoidesin was stronger in high concentration. IC50 value of melissoidesin on hydroxyl radicals and metal chelation was observed as 99 and 143 µg mL−1, respectively. The 50% inhibitory concentration of melissoidesin on lipid peroxidation was calculated as 133 µg mL−1. These findings indicate that ent kaurene diterpenoid, melissoidesin was promising antiacetylcholinesterase and antioxidant which can be used as food and drug preparations.

Protection of cadmium chloride induced DNA damage by Lamiaceae plants.

OBJECTIVE To analyze the total phenolic content, DNA protecting and radical scavenging activity of ethanolic leaf extracts of three Lamiaceae plants, i.e. Anisomelos malabarica (A. malabarica), Leucas aspera (L. aspera) and Ocimum basilicum (O. basilicum). METHODS The total polyphenols and flavonoids were analyzed in the ethanolic leaf extracts of the lamiaceae plants. To determine the DNA protecting activity, various concentrations of the plant extracts were prepared and treated on cultured HepG2 human lung cancer cells. The pretreated cells were exposed to H2O2 to induce DNA damage through oxidative stress. Comet assay was done and the tail length of individual comets was measured. Nitric oxide and superoxide anion scavenging activities of lamiaceae plants were analyzed. RESULTS Among the three plant extracts, the highest amount of total phenolic content was found in O. basilicum (189.33 mg/g), whereas A. malabarica showed high levels of flavonoids (10.66 mg/g). O. basilicum also showed high levels of DNA protecting (85%) and radical scavenging activity. CONCLUSIONS The results of this study shows that bioactive phenols present in lamiaceae plants may prevent carcinogenesis through scavenging free radicals and inhibiting DNA damage.

Evaluation of DNA damage in jewellery workers occupationally exposed to nitric oxide

Nitric oxide is a metastable radical, reacts with oxygen to produce toxic nitrogen oxides (N(2)O(3), ONOO(-)) which damage DNA. Occupational exposure to nitric oxide leads to increased frequency of chromosomal aberrations in humans. In the present study the DNA damage among the jewellery workers occupationally exposed to nitric oxide was analyzed using buccal cell comet assay. The result of this study shows increased levels of DNA damage among jewellery workers. The habit of cigarette smoking among the jewellery workers has a synergistic effect on inducing DNA damage.

Influence of rearing water temperature on induced gonadal development and spawning behaviour of tropical green mussel, Perna viridis

Abstract Objective To standardize the technique of induced breeding and spawning of green mussel Perna viridis ( P. viridis ), in captivity. Methods In Experiment-A, the temperature was increased at a rate of 2 °C/5 days interval. In Experiment-B, a rise of 3 °C/5 days was practiced, whereas in Experiment C and D, respectively 4 and 5 °C was increased in 5 days interval. The temperature was maintained constant at 20 °C in the Control. Results The increase in temperature showed a progressive effect on the gonadal development of mussels. The gonads ripped at 30 to 32 °C in all the experimental tanks, irrespective of the difference in temperature hike. Complete spawning in P. viridis was achieved by gradually raising the temperature from 20 to 35 °C at a rate of 3 or 4 °C/5 days. Conclusion According to the present study temperature induced spawning method is very simple and cost effective and can accelerate the production of mussel seeds in hatchery units and further stock improvement through genetic manipulation.

Cytotoxic and anticarcinogenic activity of the ent-kaurene diterpenoid, melissoidesin, from Isodon wightii (Bentham) H. Hara

Isodon wightii is a common plant found in the Western Ghats of South India. The ent-kaurene diterpenoid melissoidesin, isolated from the leaves of I. wightii, showed significant cytotoxicity against lung cancer and neuroblastoma cell lines with IC50 values of 6 and 4.2 µg mL−1, respectively. The prevention of deoxyribose degradation activity of melissoidesin was significant and the IC50 value was calculated to be 163.1 µg mL−1. The anticarcinogenic activity of melissoidesin by comet assay showed significant DNA damage protecting activity in a dose-dependent manner.