Radioprotection by Macerated Extract of Nigella sativa in Normal Tissues of Fibrosarcoma Bearing Mice.

The current study was undertaken to study the effect of a macerated extract of Nigella sativa seeds in normal as well as in tumour bearing mice against gamma radiation-induced cellular damage to normal tissues. This was done to mimic the clinical setting where in, normal tissues of cancer patients undergoing radiotherapy are exposed to the deleterious effects of radiation. The protection of cellular DNA was analysed in peripheral blood leucocytes of whole body irradiated mice following pretreatment with macerated extract of Nigella sativa seeds (100 mg/kg), using alkaline comet assay, and also estimating biochemical and blood parameters such as levels of antioxidant enzymes superoxide dismutase and catalase, thiobarbituric acid reactive substances and protein oxidation in organs such as spleen, liver, brain and intestine haemoglobin and total leucocyte count, respectively. The results showed that the macerated extract of Nigella sativa seeds protected the liver, spleen, brain and intestines both in normal as well as tumour bearing mice. This study concludes that macerated extract of Nigella sativa seeds has protective effects against radiation-induced damage and biochemical alterations which could be attributed to the ability to scavenge free radicals and its antioxidant properties. Hence macerated extract of Nigella sativa seeds, could be used in combination with radiation to protect against oxidative stress in normal tissues and improving the quality of life of cancer patients by mitigating unwanted side effects of radiation in normal tissues.

Radiosensitization in human breast carcinoma cells by thymoquinone: role of cell cycle and apoptosis.

TQ (thymoquinone), the bioactive constituent of black seed (Nigella sativa), has been shown to inhibit the growth of various human cancers both in vitro and in vivo. This study reports the radiosensitizing effect of TQ on human breast carcinoma cells (MCF7 and T47D). TQ in combination with single dose of ionizing radiation (2.5 Gy) was found to exert supra-additive cytotoxic effects on both the carcinomas as measured by cell proliferation and colony-formation assays. Annexin V binding and FACS analysis revealed the role of enhanced apoptosis and cell cycle modulation in the mechanism of TQ-mediated radiosensitization, thus supporting TQ as an adjuvant for preclinical testing in cancer chemo-radiotherapy.

Validated high-performance thin-layer chromatographic method for the quantification of thymoquinone in Nigella Sativa extracts and formulations.

INTRODUCTION: The surge of interest in naturally occurring phytochemicals with anticancer potential has led to the discovery of many molecules, one of them being thymoquinone (TQ) the bioactive constituent of the volatile oil of black seed, Nigella sativa L. (NS). OBJECTIVE: The aim of the present work was to develop and validate an HPTLC method for determination of TQ in NS extracts, commercially available marketed oils, polyherbal formulations and in lipid-based oral and parenteral formulations prepared in-house. METHODOLOGY: Analysis of TQ was performed on TLC aluminium plates pre-coated with silica gel 60F-254. Linear ascending development was carried out in twin trough glass chamber, saturated with mobile phase consisting of toluene-cyclohexane (8 : 2, v/v) at ambient temperature. Camag TLC scanner III was used for the spectrodensitometric scanning and analysis in absorbance mode at 254 nm. RESULTS: The method was found to give compact spots for TQ (R(f) value of 0.28 ± 0.05) and was linear over the range 100-1400 ng/spot (r(2) = 0.9921 ± 0.0020). Accuracy, precision and repeatability were all within the required limits. The mean recoveries measured at three concentrations were higher than 95% with RSD ≤ 3%. CONCLUSION: The HPTLC method developed was found to be relatively simple, rapid and accurate for the routine analysis of TQ in extracts, marketed oils, polyherbal and in-house formulations.