Effect of Terminalia arjuna extract on adriamycin-induced DNA damage.

The effect of a bark extract of Terminalia arjuna (TAE) was studied on the alteration of adriamycin (ADR)-induced micronuclei formation in cultured human peripheral blood lymphocytes. Exposure of lymphocytes to ADR resulted in a dose-dependent increase in the micronuclei formation indicating DNA damage. Pretreatment of lymphocytes with TAE before ADR treatment resulted in a significant decline in micronuclei formation. Increasing doses of ADR caused a dose-dependent increase in the frequency of lymphocytes bearing one, two and multiple micronuclei. Prior exposure of lymphocytes to 15 microg/mL of TAE significantly reduced the frequency of lymphocytes bearing one, two and multiple micronuclei when compared with ADR-treated control. TAE-inhibited the induction of (*)OH (hydroxyl), O2(*-) (superoxide), DPPH (1,1-diphenyl-2-picrylhydrazyl), ABTS(*+) (2,2-azino-bis-3-ethyl benzothiazoline-6-sulphonic acid) radicals in a dose-dependent manner. These results demonstrate that TAE protects DNA against ADR-induced damage.

Inhibition of radiation-induced clastogenicity by Aegle marmelos (L.) correa in mice bone marrow exposed to different doses of gamma-radiation.

The frequency of micronucleated polychromatic (MPCE), normochromatic erythrocytes (MNCE), and polychromatic/normochromatic erythrocyte ratio (PCE/NCE), was studied in the bone marrow of mice orally administered with 0, 200, 225, 250, 275 and 300 mg/kg body weight of hydroalcoholic leaf extract of Aegle marmelos (AME). Treatment of mice with AME, once daily for 5 consecutive days, before exposure to 2 Gy resulted in a significant decline in the frequency of MPCE when compared to the non-drug-treated irradiated control. The greatest reduction in MPCE was observed for 250 mg/kg body weight AME, accompanied by the highest polychromatic erythrocyte to normochromatic erythrocyte ratio, in comparison with the non-drug-treated irradiated control. Therefore, further studies were carried out using this dose of AME, where the animals were administered with 250 mg/kg body weight of AME before exposure to 0, 0.5, 1, 2, 3 and 4 Gy of gamma-radiation and evaluated at 12, 24, 36 and 48 hours post-irradiation. Whole body irradiation of mice to different doses of gamma-radiation resulted in a dose-dependent increase in the frequency of MPCE at all post-irradiation times. Treatment of 250 mg/kg AME orally (p.o.) before irradiation significantly reduced the frequency of MPCE at all post-treatment times. The frequency of MPCE increased with time, reached a peak level at 24 hours, and declined thereafter. The occurrence of MNCE has also shown a pattern similar to MPCE, except that the MNCE frequency reached a peak level by 48 hours. The AME significantly reduced the frequency of MNCE at all post-irradiation times, when compared to the non-drug-treated irradiated group. Treatment of mice with AME before exposure to different doses of gamma-radiation resulted in the inhibition of a radiation-induced decline in the PCE/NCE ratio, when compared with the concurrent irradiated controls. To gain insight into the mechanism of action, AME was tested for its antioxidant effects in cell-free chemical systems using H2O2/FeSO4 to generate hydroxyl (*OH) radicals, which were measured by a fluorescent probe, 2V, 7V-dichlorofluorescin diacetate (DCFH/DA). Xanthine/xanthine oxidase was used to generate superoxide (O2*-) anion radical, which was measured by a fluorescent probe dihydroethidium (DHE). AME significantly reduced fluorescence in a concentration dependent manner, indicating its efficacy to scavenge free radicals. Our results demonstrate that one of the mechanism of reduction in the radiation-induced DNA damage in mice bone marrow by AME may be due to scavenging of free radicals and elevation in the antioxidant status, as previously reported.

Antioxidant, anticlastogenic and radioprotective effect of Coleus aromaticus on Chinese hamster fibroblast cells (V79) exposed to gamma radiation.

Coleus aromaticus (Benth, Family: Laminaceae), Indian Oregano native to India and Mediterranean, is well known for its medicinal properties. A preliminary study was undertaken to elucidate in vitro free radical scavenging potential and inhibition of lipid peroxidation by C.aromaticus hydroalcoholic extract (CAE). Anti-clastogenic and radioprotective potential of CAE were studied using micronucleus assay after irradiating Chinese hamster fibroblast (V79) cells. CAE at 10, 20, 40, 60, 80, 100 and 120 mug/ml resulted in a dose-dependent increase in radical scavenging ability against various free radicals viz., 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), superoxide anion (O(2)(*-)), hydroxyl (OH(*)) and nitric oxide (NO(*)) generated in vitro. A maximum scavenging potential was noticed at 100 mug/ml and a saturation point was reached thereafter with the increasing doses of CAE. The free radical scavenging potential of the extract was in the order of DPPH > ABTS > Superoxide > Hydroxyl > Nitric oxide. CAE also exhibited a moderate inhibition of lipid peroxidation in vitro, with a maximum inhibition at 60 mug/ml (33%), attaining saturation at higher doses. The extract also rendered protection against radiation induced DNA damage, as evidenced by the significant (P < 0.05) decrease in the percentage of radiation-induced micronucleated cells (MN) and frequency of micronuclei (total). A maximum anticlastogneic effect/ radioprotection was noticed at a very low concentration i.e., 5 mug/ml of CAE, treated 1 h prior to 2 Gy of gamma radiation. A significant (P < 0.0001) anticlastogenic/radioprotective effect was also observed when the cells were treated with an optimum dose of CAE (5 mug/ml) 1 h prior to 0.5, 1, 2 and 4 Gy of gamma radiation compared with the respective radiation control groups. Overall, our results established an efficient antioxidant, anticlastogenic and radioprotective potential of CAE, which may be of great pharmacological importance.

Radioprotection by mangiferin in DBAxC57BL mice: a preliminary study.

The radioprotective effects of various concentrations (0, 0.25, 0.5, 1, 2, 5, 10, 17.5, 25, 50, 75 and 100 mg/kg b.wt.) of mangiferin (MGN) was studied in the DBAxC57BL mice whole body exposed to 10 Gy of gamma-irradiation. Treatment of mice with different doses of MGN, one hour before irradiation reduced the symptoms of radiation sickness and delayed the onset of mortality when compared with the non-drug treated irradiated controls. The radioprotective action of MGN increased in a dose dependent manner up to 2mg/kg and declined thereafter. The highest radioprotective effect was observed at 2mg/kg MGN, where greatest number of animals survived against the radiation-induced mortality. The administration of 0.5, 1, 2, 5, 10 and 17.5 mg/kg MGN reduced the radiation-induced gastrointestinal death as evident by a greater number of survivors up to 10 days in this group when compared with the DDW + 10 Gy irradiation group. A similar effect of MGN was observed for the radiation-induced bone marrow deaths also. Our study demonstrates that mangiferin, a gluosylxanthone, present in the Mangifera indica protected mice against the radiation-induced sickness and mortality and the optimum protective dose of 2mg/kg was 1/200 of LD50 dose (400 mg/kg) of MGN. The administration of 400 mg/kg MGN induced 50% mortality, therefore LD50 of the drug was considered to be 400 mg/kg.

Radioprotective effect of abana, a polyherbal drug following total body irradiation.

Effects of 20 mg/kg body weight of abana (ABE) on radiation-induced sickness and mortality in mice exposed to 7 Gy to 12 Gy of gamma irradiation were studied. Treatment of mice with abana 1 h before irradiation delayed the onset of mortality and reduced the symptoms of radiation sickness when compared with the non-drug treated irradiated controls (double distilled water, DDW). Abana provided protection against both the gastrointestinal and haemopoietic deaths. However, animals of both the ABE+irradiation and DDW+irradiation groups did not survive up to 30 days post-irradiation beyond 11 Gy irradiation. The LD(50/30) was found to be 8.5 Gy for the DDW+irradiation group and 10.3 Gy for ABE+irradiation group. The administration of abana resulted in an increase in radiation tolerance by 1.8 Gy, and the dose modification factor (DMF) was found to be 1.2. The irradiation of animals resulted in a dose dependent elevation in lipid peroxidation, and a reduction in glutathione (GSH) concentration on day 31 post-irradiation. Treatment of mice with abana before irradiation caused a significant depletion in lipid peroxidation followed by a significant elevation in GSH concentration in the liver of mice at day 31 post-irradiation. Abana scavenged (*)OH, DPPH, ABTS(*+) and NO(*) in a concentration dependent manner in vitro. Our results indicate that the radioprotective activity of abana may be due to free radical scavenging and increased GSH level in irradiated mice.

Evaluation of the radioprotective effect of bael leaf (Aegle marmelos) extract in mice.

PURPOSE: To investigate the radioprotective activity of a leaf extract of bael leaf (Aegle marmelos) (AME) in mice exposed to different doses of gamma-radiation. MATERIALS AND METHODS: The acute toxicity of AME was evaluated in Swiss albino male mice administered various intraperitoneal single doses of AME. For radioprotection studies, mice were administered different doses, 0, 5, 10, 15, 20 or 40 mg kg(-1), of AME or sterile physiological saline intraperitoneally once daily consecutively for 5 days before exposure to 10 Gy 60Co gamma-radiation or five doses of 15 mg kg(-1) AME before exposure to 6, 7, 8, 9, 10 or 11 Gy. The animals were monitored for symptoms of radiation sickness and mortality up to 30 days post-irradiation. Glutathione and lipid peroxidation were estimated in the surviving animals of both groups on day 31 post-irradiation. RESULTS: AME was non-toxic up to a single dose of 1750 mg kg(-1). The optimum radioprotective dose was five consecutive doses of 15 mg kg(-1) AME, where the highest survival to 10 Gy radiation was observed. The irradiation caused a dose-dependent decline in survival, while treatment of mice with AME enhanced survival. The dose reduction factor was 1.15. Irradiation caused a dose-dependent decline in the level of glutathione accompanied by an elevation in lipid peroxidation. AME pretreatment arrested glutathione decline and lipid peroxidation significantly. CONCLUSION: AME treatment reduced the symptoms of radiation-induced sickness and increased survival. The radioprotective action might be due to free-radical scavenging and arrest of lipid peroxidation accompanied by an elevation in glutathione.

Effect of curcumin on radiation-impaired healing of excisional wounds in mice.

OBJECTIVE: To study the effect on wound contraction of pretreatment with various doses of curcumin (the most important active ingredient of the spice turmeric) in mice exposed to 6 Gy whole-body gamma radiation. METHOD: A full-thickness skin wound was produced on the dorsum of Swiss albino mice treated with and without 25, 50, 100, 150 or 200 mg/kg body weight of curcumin before exposure to 6 Gy gamma radiation. Progression of wound contraction was monitored using video images of the wound at various days post-irradiation until full healing occurred. Mean wound healing times were also calculated. RESULTS: Irradiation caused significant delay in wound contraction and healing times. However, treatment with curcumin resulted in a dose-dependent increase in contraction when compared with a control. Greatest contraction was observed for 100 mg/kg curcumin, with statistically significant results at days three (p < 0.009), six (p < 0.05) and nine (p < 0.05) post-irradiation for this dose. Complete healing was achieved by day 23 post-irradiation in the curcumin-treated irradiation group. CONCLUSION: Pretreatment with curcumin has a conductive effect on irradiated wounds. It could be a substantial therapeutic agent for ameliorating radiation-induced delay in wound repair in cases of combined injuries.

The evaluation of the radioprotective effect of Triphala (an ayurvedic rejuvenating drug) in the mice exposed to gamma-radiation.

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 highest protection against GI (gastrointestinal) death was observed for 12.5 mg/kg triphala, where a highest number of survivors were reported up to 10 days post-irradiation. While 10 mg/kg triphala i.p. provided the best protection as evidenced by the highest number of survivors after 30 days post-irradiation in this group when compared with the other doses of triphala. Toxicity study showed that triphala was non-toxic up to a dose of 240 mg/kg, where no drug-induced mortality was observed. The LD50 dose i.p. of triphala was found to be 280 mg/kg b. wt. Our study demonstrates the ability of triphala as a good radioprotective agent and the optimum protective dose of triphala was 1/28 of its LD50 dose.

Evaluation of the antineoplastic activity of guduchi (Tinospora cordifolia) in cultured HeLa cells.

Exposure of HeLa cells to 0, 5, 10, 25, 50 and 100 microg/ml of guduchi extracts (methanol, aqueous and methylene chloride) resulted in a dose-dependent but significant increase in cell killing, when compared to non-drug-treated controls. The effects of methanol and aqueous extracts were almost identical. However, methylene chloride extract enhanced the cell killing effect by 2.8- and 6.8-fold when compared either to methanol or aqueous extract at 50 and 100 microg/ml, respectively. Conversely, the frequency of micronuclei increased in a concentration-dependent manner in guduchi-treated groups and this increase in the frequency of micronuclei was significantly higher than the non-drug-treated control cultures and also with respect to 5 microg/ml guduchi extract-treated cultures, at the rest of the concentrations evaluated. Furthermore, the micronuclei formation was higher in the methylene chloride extract-treated group than in the other two groups. The dose response relationship for all three extracts evaluated was linear quadratic. The effect of guduchi extracts was comparable or better than doxorubicin treatment. The micronuclei induction was correlated with the surviving fraction of cells and the correlation between cell survival and micronuclei induction was found to be linear quadratic. Our results demonstrate that guduchi killed the cells very effectively in vitro and deserves attention as an antineoplastic agent.

The herbal preparation abana protects against radiation-induced micronuclei in mouse bone marrow.

The induction of micronuclei was studied in mouse bone marrow treated or not with 5, 10 and 20 mg/kg b.wt. of abana (a herbal preparation) before exposure to 0-3 Gy of gamma-radiation. Whole-body irradiation of mice resulted in a dose-dependent increase in the frequency of micronuclei. Treatment of mice with various doses of abana before exposure to different doses of gamma-rays resulted in a significant reduction of the micronucleus frequency at all exposure doses. The highest decline in the frequencies of micronuclei was observed after administration of 20 mg/kg abana, where the frequency of micronuclei was approximately 4-fold less than that of the concurrent control. The PCE/NCE ratio was significantly higher in the drug-treated group compared to DDW + irradiated control and it was almost restored to normal level after administration of 20 mg/kg abana. Our results demonstrate that abana protects mice against radiation-induced micronucleus formation and radiation-induced decline in cell proliferation.

Treatment of mice with a herbal preparation (Liv. 52) reduces the frequency of radiation-induced chromosome damage in bone marrow.

Induction of chromosomal aberrations was studied from 1/4 to 14 days post irradiation in the bone marrow of mice treated or not with Liv. 52, a herbal preparation, prior to 4.5 Gy exposure. The frequency of chromatid and chromosomal aberrations started increasing at day 1/4 in the irradiation and Liv. 52 + irradiated groups. The highest frequency of aberrations was recorded at day 1/2 post exposure which declined after day 1 in both groups. The frequency of both types of aberrations was significantly lower in the Liv. 52 + irradiated group than in the irradiated group.

Inhibition of clastogenic effect of radiation by Liv. 52 in the bone marrow of mice.

The frequency of micronuclei in bone marrow cells of mice treated or not with Liv. 52 and then exposed to 4.5 Gy of gamma-radiation was evaluated from 6 h to 14 days post irradiation. The frequency of micronuclei increased from 6 h to 24 h post irradiated in both irradiated groups and declined thereafter, the frequency of micronuclei remaining significantly lower in the Liv. 52-treated group. These data demonstrate that Liv. 52 protects the bone marrow of mice against radiation injury.