Preferential radioprotection to DNA of normal tissues by ferulic acid under ex vivo and in vivo conditions in tumor bearing mice

Plant based radioprotectors as an adjunct to radiotherapy: advantages and limitations

Radioprotectors are agents that have the potential to act against radiation damage to cells. These are equally invaluable in radiation protection, both in intentional and unintentional radiation exposure. It is however, complex to use a universal radioprotector that could be beneficial in diverse contexts such as in radiotherapy, nuclear accidents, and space travel, as each of these circumstances have unique requirements. In a clinical setting such as in radiotherapy, a radioprotector is used to increase the efficacy of cancer treatment. The protective agent must act against radiation damage selectively in normal healthy cells while enhancing the radiation damage imparted on cancer cells. In the context of radiotherapy, plant-based compounds offer a more reliable solution over synthetic ones as the former are less expensive, less toxic, possess synergistic phytochemical activity, and are environmentally friendly. Phytochemicals with both radioprotective and anticancer properties may enhance the treatment efficacy by two-fold. Hence, plant based radioprotective agents offer a promising field to progress forward, and to expand the boundaries of radiation protection. This review is an account on radioprotective properties of phytochemicals and complications encountered in the development of the ideal radioprotector to be used as an adjunct in radiotherapy.

Protective Effect of JXT Ethanol Extract on Radiation-Induced Hematopoietic Alteration and Oxidative Stress in the Liver

This study aims at investigating the radioprotective effect of ethanol extract from Ji-Xue-Teng (JXT, Spatholobus suberectus) on radiation-induced hematopoietic alteration and oxidative stress in the liver. Mice were exposed to a single acute γ-radiation for the whole body at the dose of 6.0 Gy, then subjected to administration of amifostine (45 mg/kg) or JXT (40 g crude drug/kg) once a day for 28 consecutive days, respectively. Bone marrow cells and hemogram including white cells, red cells, platelet counts, and hemoglobin level were examined. The protein expression levels of pJAK2/JAK2, pSTAT5a/STAT5a, pSTAT5b/STAT5b, and Bcl-2 in bone marrow tissue; levels of reactive oxygen species (ROS); and the activity of superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione peroxidase (GSH-Px) in serum and liver tissue were determined. At the end of the experiment, the effect of JXT on cell viability and G-CSF and G-CSFR levels in NFS-60 cells were tested by CCK-8 assay, ELISA, and flow cytometry. The results showed that the mice exposed to γ-radiation alone exhibited a typical hematopoietic syndrome. In contrast, at the end of the 28-day experiment, irradiated mice subjected to oral administration of JXT showed an obvious improvement on blood profile with reduced leucopenia, thrombocytopenia (platelet counts), RBC, and hemoglobin levels, as well as bone marrow cells. The expression of pJAK2/JAK2, pSTAT5a/STAT5a, and Bcl-2 in bone marrow tissue was increased after JXT treatment. The elevation of ROS was due to radiation-induced toxicity, but JXT significantly reduced the ROS level in serum and liver tissue, elevated endogenous SOD and GSH-PX levels, and reduced the MDA level in the liver. JXT could also increase cell viability and G-CSFR level in NFS-60 cells, which was similar to exogenous G-CSF. Our findings suggested that oral administration of JXT effectively facilitated the recovery of hematopoietic bone marrow damage and oxidative stress of the mice induced by γ-radiation.

Radioprotective effects of dammarane sapogenins against 60 Co-induced myelosuppression in mice

Radiotherapy frequently induces failure of hematopoietic system and leads to myelosuppression. The objective of this study was to investigate the protective effect of dammarane sapogenins (DS), the hydrolysed product of the constituent ginsenosides of Panax ginseng, which are produced by gut metabolism, on radiation-induced hematopoietic injury. Mice were exposed to 3.5 Gy 60 Co γ-rays of total body radiation at a dose rate of 1.60 Gy per minute and treated with DS or granulocyte colony-stimulating factor immediately after radiation. The general condition of the mice, the peripheral blood cell counts, multiple colony forming unit (CFU) assays of hematopoietic progenitor cells, hematopoietic stem cell counts, bone marrow histology, and spleen colony forming unit counts were then investigated. Our results indicated that administration with DS could ameliorate 60 Co-irradiation induced damage and significantly increase the number of peripheral blood cells (white blood cells and platelets), 5 types of hematopoietic progenitor cells CFU (CFU-GM, CFU-E, BFU-E, CFU-Meg, and CFU-GEMM), hematopoietic stem cell (Lin- c-kit+ Scal-1+ ) numbers, and CFUs in the spleen, as well as improved bone marrow histopathology. All together, these results confirmed the enhancement of DS on hematopoiesis.

Biosynthesis, natural sources, dietary intake, pharmacokinetic properties, and biological activities of hydroxycinnamic acids

Hydroxycinnamic acids are the most widely distributed phenolic acids in plants. Broadly speaking, they can be defined as compounds derived from cinnamic acid. They are present at high concentrations in many food products, including fruits, vegetables, tea, cocoa, and wine. A diet rich in hydroxycinnamic acids is thought to be associated with beneficial health effects such as a reduced risk of cardiovascular disease. The impact of hydroxycinnamic acids on health depends on their intake and pharmacokinetic properties. This review discusses their chemistry, biosynthesis, natural sources, dietary intake, and pharmacokinetic properties.

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.

Ferulic acid, a dietary phenolic acid, modulates radiation effects in Swiss albino mice

The radioprotective efficacy of Ferulic acid (FA) against whole body gamma radiation was studied in Swiss albino mice. To study the radiation protection, mice were administered with ferulic acid intraperitoneally (i.p) (50 mg/kg body weight.), once daily for five consecutive days. One hour after the last administration of ferulic acid on the sixth day, animals were whole body exposed to 8 Gy gamma radiations. Effect of ferulic acid pretreatment on radiation-induced changes in antioxidant enzymes and lipid peroxidation status in spleen, liver and intestine was analyzed. A significant increase in the antioxidant enzymatic status and decreased lipid peroxidation marker levels were observed in ferulic acid pretreated group, when compared to the irradiated animals. Our study also shows increased % tail DNA, tail length, tail moment and Olive tail moment in irradiated mice blood lymphocytes. Ferulic acid (50 mg/kg body weight) pretreatment significantly decreased the % tail DNA, tail length, tail moment and Olive tail moment in irradiated mice lymphocytes. The histological observations indicated a decline in the villus height and crypt number with an increase in goblet and dead cell population in the irradiated group, which was normalized by ferulic acid pretreatment. In conclusion, present study indicated ferulic acid treatment prevents radiation-induced lipid peroxidation, DNA damage and restored antioxidant status and histopathological changes in experimental animals.

Polysaccharides isolated from Ganoderma lucidum occurring in Southern parts of India, protects radiation induced damages both in vitro and in vivo

The in vivo and in vitro radioprotective property of the polysaccharides isolated from Ganoderma lucidum were determined by survival studies, induction of micronucleus in reticulocytes of mice, strand breaks in plasmid pBR322 DNA and inhibition of lipid peroxidation (TBARS assay). Polysaccharides were administered as a single dose after whole body exposure to 10Gy (60)Co γ-radiation to Swiss albino mice. At a dose of 500μg/kg body wt, the polysaccharides were most effective in protecting animals from radiation induced loss of lethality. Administration of 500μg/kg body wt to animal exposed to 10Gy gamma radiation resulted in more than 60% survival on the 30th day compared to the dose of 300mg/kg/body wt administration of amifostine, a clinically used radioprotective drug. The induction of micronuclei was reduced by the administration of polysaccharides. The decrease in micronuclei induction was dose dependent. Thus following 4Gy exposure the micronuclei in polychromatic erythrocytes (MNCE) was reduced from 28.16±3.049 to 16.0243±2.074 and 6.30±2.422 by polysaccharides at doses of 250μg/kg body wt and 500μg/kg body wt, respectively, and to 10.4±2.581 by amifostine at a dose of 300mg/kg body wt. The results indicate the significant protective effect of Ganoderma polysaccharides against radiation induced damages. The findings thus suggest the potential use of Ganoderma polysaccharides as novel radioprotective agent.

Chemistry, natural sources, dietary intake and pharmacokinetic properties of ferulic acid: A review

Ferulic acid (FA) is an abundant dietary antioxidant which may offer beneficial effects against cancer, cardiovascular disease, diabetes and Alzheimer's disease. The impact of FA on health depends on its intake and pharmacokinetic properties. In this article, the literature pertaining to chemistry, natural sources, dietary intake and pharmacokinetic properties of FA is critically reviewed. High levels of FA are found in both free and bound forms in vegetables, fruits, cereals, and coffee. We have estimated that consumption of these foods may result in approximately 150-250mg/day of FA intake. FA can be absorbed along the entire gastrointestinal tract and metabolized mainly by the liver. The absorption and metabolism of FA seem to be dose dependent at least in experimental settings. Further pharmacokinetic and pharmacodynamic studies are required to characterize the impact of FA on human health.