Radiation-Protective Agents

Aqueous extract of a natural herb, Terminalia chebula was tested for potential antioxidant activity by examining its ability to inhibit gamma-radiation-induced lipid peroxidation in rat liver microsomes and damage to superoxide dismutase enzyme in rat liver mitochondria. The antimutagenic activity of the extract has been examined by following the inhibition of gamma-radiation-induced strand breaks formation in plasmid pBR322 DNA.

Radioprotective ability of the aqueous extract of the fruit of Terminalia chebula (TCE) was evaluated for its antioxidant and radioprotective abilities. TCE (50 microg) was able to neutralise 1,1-diphenyl-2-picrylhydrazyl, a stable free radical by 92.9%. The free radical neutralizing ability of TCE was comparable to that of ascorbate (100 microM) 93.5% and gallic acid (100 microM) 91.5% and was higher than that of the diethyldithiocarbamate (200 microM) 55.4%, suggesting the free radical activity of TCE.

CONTEXT: The fruit of Terminalia chebula Retz. (Combretaceae) has been used for several therapeutic purposes in Thai folk medicines. Currently, the ethanol extracts containing antioxidant compounds have shown the ability to promote collagen synthesis. OBJECTIVE: This purpose of this work was to study the effects of the ethanol extract from T. chebula fruit on the inhibition of cutaneous photodamage. MATERIALS AND METHODS: The viability of human skin fibroblasts after incubation with T.

Rasayana tantra is one of the eight specialties of Ayurveda. It is a specialized practice in the form of rejuvenative recipes, dietary regimen, special health promoting behaviour and drugs. Properly administered Rasayana can bestow the human being with several benefits like longevity, memory, intelligence, freedom from diseases, youthful age, excellence of luster, complexion and voice, optimum strength of physique and sense organs, respectability and brilliance. Various types of plant based Rasayana recipes are mentioned in Ayurveda.

Rasayanas are a group of herbal drug preparations widely used in Ayurveda to improve the general health of the body. In mice, Rasayanas are potent myeloprotective agents against chemotherapeutic agents and radiation. Rasayanas are also effective myeloprotectors in patients with cancer undergoing chemotherapy and/or radiotherapy. In this study, we provide further evidence to support the chemoprotective and radioprotective efficacy of four Rasayanas in mice. Rasayanas were found to reduce the loss of body weight and organ weight induced by cyclophosphamide and radiation significantly.

The effects of 10 mg/kg of triphala extract (TE) was studied on radiation-induced sickness and mortality in mice exposed to 7-12 Gray (Gy) of gamma-irradiation. Treatment of mice with triphala once daily for 5 consecutive days before irradiation delayed the onset of mortality and reduced the symptoms of radiation sickness when compared with the non-drug double distilled water treated irradiated controls (DDW). Triphala provided protection against both gastrointestinal and hemopoetic death.

The effective use of radiotherapy in cancer cure and palliation is compromised by the side-effects resulting from radiosensitivity of bordering normal tissues, which are invariably exposed to the cytotoxic effects of ionizing radiation during treatment. In this situation, use of radioprotective compounds that can protect normal tissues against radiation injury are of immense use. In addition to protecting normal tissue these compounds will also permit use of higher radiation doses to obtain better cancer control and possible cure.

The effect of 0, 5, 6.25, 10, 12.5, 20, 25, 40, 50 and 80 mg/kg b. wt. of aqueous extract of triphala (an Ayurvedic herbal medicine) administrered intraperitoneally was studied on the radiation-induced mortality in mice exposed to 10 Gy of gamma-radiation. Treatment of mice with different doses of triphala consecutively for five days before irradiation delayed the onset of mortality and reduced the symptoms of radiation sickness when compared with the non-drug treated irradiated controls.

The effect of 5, 10, 20, 40, 60, 80, 100, 120, and 160 mg/kg body weight (b.wt.) of aqueous extract of cystone (an ayurvedic herbal medicine) administered intraperitoneally was studied on the radiation-induced mortality in mice exposed to 10 Gy of gamma-radiation. Treatment of mice with different doses of cystone, consecutively for five days before irradiation, delayed the onset of mortality and reduced the symptoms of radiation sickness when compared with the non-drug treated irradiated controls.

Rasayanas are a group of herbal drug preparations widely used in Ayurveda to improve the general health of the body. In mice, Rasayanas are potent myeloprotective agents against chemotherapeutic agents and radiation. Rasayanas are also effective myeloprotectors in patients with cancer undergoing chemotherapy and/or radiotherapy. In this study, we provide further evidence to support the chemoprotective and radioprotective efficacy of four Rasayanas in mice. Rasayanas were found to reduce the loss of body weight and organ weight induced by cyclophosphamide and radiation significantly.