Development of Deltamethrin-Laced Attractive Toxic Sugar Bait to Control Aedes aegypti (Linnaeus) Population.

Background: The attractive toxic sugar bait (ATSB) is a promising strategy for controlling mosquitoes at the adult stage. The strategy is based on the use of a combination of fruit juice, sugar, and a toxin in order to attract and kill the adult mosquitoes. The selection of the components and optimization of their concentrations is significant for the formulation of an effective ATSB. Methods: The present study formulated nine ATSBs and evaluated their efficacy against two laboratory strains (AND-Aedes aegypti and AND-Aedes aegypti-DL10) and two wildcaught colonized strains of Aedes aegypti (GVD-Delhi and SHD-Delhi). Initially, nine attractive sugar baits (ASBs) were prepared using a mixture of 100% fermented guava juice (attractant) with 10% sucrose solution (w/v) in 1 : 1 ratio. ATSBs were formulated by mixing each ASB with different concentrations of deltamethrin in the ratio of 9 : 1 to obtain final deltamethrin concentration of 0.003125-0.8 mg/10 mL ATSB. Cage bioassays were conducted with 50 mosquitoes for 24 h in order to evaluate the efficacy of each ATSB against the four strains of Ae. aegypti. The data were statistically analyzed using PASW software 19.0 program and 2-way ANOVA. Results: The ATSB formulations registered 8.33-97.44% mortality against AND-Aedes aegypti and 5.15-96.91% mortality against AND-Aedes aegypti-DL10 strains of Ae. aegypti, while GVD-Delhi strain registered 2.04-95.83% mortality and SHD-Delhi strain showed 5.10-97.96% mortality. The administration of 0.8 mg of deltamethrin within 10 mL of attractive toxic sugar bait (ATSB) has led to the maximum mortality rate in adult mosquitoes. Conclusions: The ATSBs formulated with guava juice-ASB and deltamethrin (9 : 1) showed toxin dose-dependent toxicity by all the four strains of Ae. aegypti. Most effective dosage was found as 0.8 mg deltamethrin/10 mL ATSB which imparted 96% to 98% mortality in adult mosquitoes. The investigations demonstrated the efficacy of deltamethrin-laced ATSB formulations against Ae. aegypti and highlighted the need for conduct of structured field trials and investigating the impact on disease vectors and nontarget organisms.

Laboratory evaluation of the efficacy of deltamethrin-laced attractive toxic sugar bait formulation on Anopheles stephensi.

BACKGROUND: Attractive toxic sugar bait (ATSB) is a promising "attract and kill"-based approach for mosquito control. It is a combination of flower nectar/fruit juice to attract the mosquitoes, sugar solution to stimulate feeding, and a toxin to kill them. Selecting an effective attractant and optimizing concentration of toxicant is significant in the formulation of ATSB. METHODS: Current study formulated an ATSB using fruit juice, sugar and deltamethrin, a synthetic pyrethroid. It was evaluated against two laboratory strains of Anopheles stephensi. Initial studies evaluated comparative attractiveness of nine different fruit juices to An. stephensi adults. Nine ASBs were prepared by adding fermented juices of plum, guava, sweet lemon, orange, mango, pineapple, muskmelon, papaya, and watermelon with 10% sucrose solution (w/v) in 1:1 ratio. Cage bioassays were conducted to assess relative attraction potential of ASBs based on the number of mosquito landings on each and the most effective ASB was identified. Ten ATSBs were prepared by adding the identified ASB with different deltamethrin concentrations (0.015625-8.0 mg/10 mL) in 1:9 ratio. Each ATSB was assessed for the toxic potential against both the strains of An. stephensi. The data was statistically analysed using PASW (SPSS) software 19.0 program. RESULTS: The cage bioassays with nine ASBs revealed higher efficacy (p < 0.05) of Guava juice-ASB > Plum juice-ASB > Mango juice-ASB in comparison to rest of the six ASB's. The bioassay with these three ASB's ascertained the highest attractancy potential of guava juice-ASB against both the strains of An. stephensi. The ATSB formulations resulted in 5.1-97.9% mortality in Sonepat (NIMR strain) with calculated LC30, LC50, and LC90 values of 0.17 mg deltamethrin/10 mL, 0.61 mg deltamethrin/10 mL, and 13.84 mg deltamethrin/10 mL ATSB, respectively. Whereas, 6.12-86.12% mortality was recorded in the GVD-Delhi (AND strain) with calculated LC30, LC50, and LC90 values of 0.25 mg deltamethrin/10 mL, 0.73 mg deltamethrin/10 mL and 10.22 mg deltamethrin/10 mL ATSB, respectively. CONCLUSION: The ATSB formulated with guava juice-ASB and deltamethrin (0.0015625-0.8%) in 9:1 ratio showed promising results against two laboratory strains of An. stephensi. Field assessment of these formulations is being conducted to estimate their feasibility for use in mosquito control.

Attractive Sugar Bait Formulation for Development of Attractive Toxic Sugar Bait for Control of Aedes aegypti (Linnaeus).

Background: Attractive toxic sugar bait (ATSB), based on "attract and kill" approach, is a novel and promising strategy for mosquito control. Formulation of an attractive sugar bait (ASB) solution by selecting an efficient olfaction stimulant and preparation of an optimized sugar-attractant dosage is a significant component for the success of the approach. Methods: Current study evaluated relative potential of nine ASBs, formulated by combination of sugar and fresh fruit juices (guava, mango, muskmelon, orange, papaya, pineapple, plum, sweet lemon, and watermelon) in attracting Aedes aegypti adults. Freshly extracted and 48-hour-fermented juices were combined with 10% sucrose solution (w/v) in 1 : 1 ratio. Cage bioassays were conducted against two laboratory strains (susceptible: AND-Aedes aegypti; deltamethrin-selected: AND-Aedes aegypti-DL10) and two field-collected strains (Shahdara strain of Aedes aegypti: SHD-Delhi; Govindpuri strain of Aedes aegypti: GVD-Delhi). Each of the nine ASBs was assayed, individually or in groups of three, for its attraction potential based on the relative number of mosquito landings. The data were analysed for statistical significance using PASW (SPSS) software 19.0 program. Results: The prescreening bioassay with individual ASB revealed significantly higher efficacy of ASB containing guava/plum/mango juice than that containing six other juices (p < 0.05) against both the laboratory and field strains. The bioassay with three ASBs kept in one cage, one of the effective ASBs and two others randomly selected ASBs, also showed good attractancy of the guava/plum/mango juice-ASB (p < 0.05). The postscreening assays with these three ASBs revealed maximum attractant potential of guava juice-sucrose combination for all the four strains of Ae. aegypti. Conclusion. Guava juice-ASB showed the highest attractancy against both laboratory and field-collected strains of Ae. aegypti and can be used to formulate ATSB by combining with a toxicant. The field studies with these formulations will ascertain their efficacy and possible use in mosquito management programs.

Radioprotective and antioxidant activity of fractionated extracts of berries of Hippophae rhamnoides.

Plants are an abundant source of medicinal compounds, some of which are useful in combating free radical-mediated oxidative stress. In the present study, initially two fractions designated REC-1001 (flavonoid-rich fraction) and REC-1002 (flavonoid-poor fraction) of Hippophae rhamnoides were screened on the basis of their reducing power in the aqueous phase. REC-1001 was selected for further study, since it exhibited 27.38 times higher antioxidant activity than REC-1002. REC-1001 also showed significant (P < .05) membrane protection potential at 50 microg/mL, which was attributed to its ability to scavenge peroxyl radicals (64.82 +/- 1.25% scavenging within 1,440 min). A significant (P < .05) difference of 67.02% in free radical scavenging activity at 1,000 ng/mL between REC-1001 and vitamin E demonstrated the extract fraction's worth in radiation protection. Such activities were attributed to the presence of quercetin, isorhamnetin, and kaempferol in this fraction. Further, REC-1001 was found to be nontoxic up to 200 mg/kg of body weight. This research suggests that the REC-1001 fraction of H. rhamnoides extract is a safe and effective antioxidant nutraceutical product.

Neuroprotective effect of BDNF in young and aged 6-OHDA treated rat model of Parkinson disease.

Brain derived neurotrophic factor (BDNF) has been shown to exert trophic effects on dopaminergic neurons against 6-hydroxydopamine (6-OHDA) in young rat. Since the degeneration of substantia nigra dopaminergic neurons that occurs in Parkinson's disease is more often than not confined to elderly individuals, it is of interest to determine whether the effects of BDNF against 6 hydroxydopamine (6-OHDA) in young rats can be extended to aged animals. 6-hydroxydopamine was stereotaxically injected into the striatum of young (3-months) and aged (24-months) rats, which were treated two hours earlier with BDNF. 6-OHDA results in almost complete destruction of substantia nigra pars compacta dopaminergic neurons. BDNF injection significantly changed apomorphine induced rotations from 132 +/- 15 to 181 +/- 10, staircase test from 73 +/- 2% to 61 +/- 3%, initiation time from 7 +/- 2 to 12 +/- 1 sec, and disengage time from 80 +/- 7 to 90 +/- 5 sec in young and aged animals, respectively. It is concluded that BDNF causes the limited behavior recovery of striatal DA systems from 6-OHDA toxicity in aged animals.

Protection of the hemopoietic system by Podophyllum hexandrum against gamma radiation-induced damage.

A semi-purified extract of low-altitude Podophyllum hexandrum (REC-2001) containing a relatively low content of podophyllotoxin (3.25 %) exhibited potent antioxidant ability in lipid media (at 1000 microg/mLagainst 0.25 kGy) and significant (p < 0.05) hydroxyl ion scavenging potential (78.83 % at 500 microg/mL). In vitro investigations revealed the ability of REC-2001 to significantly (p < 0.05) reduce radiation-induced hemolysis (2 microg/mL; 46.184 %) and nitric oxide scavenging levels (IC (50): 792 +/- 1.25 microg/mL). Protection of the hemopoietic system of Strain 'A' mice administered 20 mg/kg BW REC-2001 30 min prior to lethal irradiation (10 Gy) was recorded and was mediated by free radical scavenging and lowering of lipid oxidation. Further studies investigating the effects of REC-2001 on stem cell modulation are warranted.

The endophytic fungus Trametes hirsuta as a novel alternative source of podophyllotoxin and related aryl tetralin lignans.

The aryl tetralin lignans are synthesized by Podophyllum sps. and are in great demand worldwide due to their use in synthesis of topoisomerase inhibitors. However, the sustained production of these aryl tetralin lignans requires large-scale harvesting from the natural environments, which has resulted in the plant-endangered status. In view of the difficulties in their total chemical synthesis, cultivation and failure of metabolic engineering approaches, there is a need to search for alternative sources of production of aryl tetralin lignans. We unequivocally established the methodology for isolation, identification, and characterization of a novel fungal endophyte (Trametes hirsuta) that produces aryl tetralin lignans consistently as shown by HPLC, LC-MS, LC/MS-MS and (1)H NMR. The lignans produced by the microorganism are biologically active, and exhibit potent antioxidant, anticancer and radioprotective properties. This strategy promises to improve the production of these therapeutically important compounds at lower costs.

3-O-beta-D-Galactopyranoside of quercetin as an active principle from high altitude Podophyllum hexandrum and evaluation of its radioprotective properties.

The aqueous-ethanolic extract (AEE) of high altitude Podophyllum hexandrum has earlier been reported to render a radioprotective effect against lethal gamma radiation in in vitro model. AEE has also been reported to possess metal chelating and DNA protecting properties. The present study was undertaken to isolate and characterize the bioactive principle present in AEE and investigate its role in radiation protection. A novel molecule was found to be present in AEE and was assigned as 3-O-beta-D-galactoside of quercetin by acid hydrolysis, LC-MS, LC-APCI-MS/MS and 13C NMR spectra. Various biological activities were investigated at in vitro level. The antioxidant potential of AEE in lipid and aqueous phase was determined against numerous stresses. AEE was found to be significantly (p < 0.05) protective, i.e., against Fe2+ and Cu2+-induced linoleic acid degradation, respectively. Radiation-induced lipid oxidation studies revealed that AEE maximally works at a [lignan]/0.25 kGy ratio 400 (ratio of concentration of AEE divided by the radiation dose, i.e., 0.25 kGy) and no drug-induced lipid oxidation at all concentrations tested was found. In a time-dependent study, total antioxidant activity was maximally exhibited at 1 mg/ml. The site-specific and non-site-specific deoxyribose degradation assay exhibited a dose-dependant hydroxyl scavenging potential of AEE (0.05-500 microg/ml). The anti-lipid peroxidation ability of AEE against radiation (0.25 kGy)-induced lipid peroxidation was higher in case of neural tissue homogenate as compared to kidney homogenate [activity ratio: 0.039 (brain) < 0.24 (kidney)]. The protein protection study using bovine serum albumin was also done for two time intervals (2 h and 4 h) and significant (p < 0.05) protection was observed at 500 microg/ml (> 97%). This study implies that 3-O-beta-D-galactoside present in AEE renders radioprotection by protecting lipids, proteins in renal and neural model system against supra-lethal (0.25 kGy) gamma radiation.

Antioxidant activity of fractionated extracts of rhizomes of high-altitude Podophyllum hexandrum: role in radiation protection.

Whole extract of rhizomes of Podophyllum hexandrum has been reported earlier by our group to render whole-body radioprotection. High-altitude P. hexandrum (HAPH) was therefore fractionated using solvents of varying polarity (non-polar to polar) and the different fractions were designated as, n-hexane (HE), chloroform (CE), alcohol (AE), hydro-alcohol (HA) and water (WE). The total polyphenolic content (mg% of quercetin) was determined spectrophotometrically, while. The major constituents present in each fraction were identified and characterized using LC-APCI/MS/MS. In vitro screening of the individual fractions, rich in polyphenols and lignans, revealed several bioactivities of direct relevance to radioprotection e.g. metal-chelation activity, antioxidant activity, DNA protection, inhibition of radiation (250 Gy) and iron/ascorbate-induced lipid peroxidation (LPO). CE exhibited maximum protection to plasmid (pBR322) DNA in the plasmid relaxation assay (68.09% of SC form retention). It also showed maximal metal chelation activity (41.59%), evaluated using 2,2'-bipyridyl assay, followed by AE (31.25%), which exhibited maximum antioxidant potential (lowest absorption unit value: 0.0389 +/- 0.00717) in the reducing power assay. AE also maximally inhibited iron/ascorbate-induced and radiation-induced LPO (99.76 and 92.249%, respectively, at 2000 microg/ml) in mouse liver homogenate. Under conditions of combined stress (radiation (250 Gy) + iron/ascorbate), at a concentration of 2000 microg/ml, HA exhibited higher percentage of inhibition (93.05%) of LPO activity. HA was found to be effective in significantly (p < 0.05) lowering LPO activity over a wide range of concentrations as compared to AE. The present comparative study indicated that alcoholic (AE) and hydro-alcoholic (HA) fractions are the most promising fractions, which can effectively tackle radiation-induced oxidative stress.

Evaluation of radioprotective activities Rhodiola imbricata Edgew--a high altitude plant.

The present study reports the radioprotective properties of a hydro-alcoholic rhizome extract of Rhodiola imbricata (code named REC-7004), a plant native to the high-altitude Himalayas. The radioprotective effect, along with its relevant superoxide ion scavenging, metal chelation, antioxidant, anti-lipid peroxidation and anti-hemolytic activities was evaluated under both in vitro and in vivo conditions. Chemical analysis showed the presence of high content of polyphenolics (0.971 +/- 0.01 mg% of quercetin). Absorption spectra analysis revealed constituents that absorb in the range of 220-290 nm, while high-performance liquid chromatography (HPLC) analysis confirmed the presence of four major peaks with retention times of 4.780, 5.767, 6.397 and 7.577 min. REC-7004 was found to lower lipid oxidation significantly (p < 0.05) at concentrations viz., 8 and 80 microg/ml respectively as compared to reduced glutathione, although the optimally protective dose was 80 microg/ml, which showed 59.5% inhibition of induction of linoleic acid degradation within first 24 h. The metal chelation activity of REC-7004 was found to increase concomitantly from 1 to 50 microg/ml. REC-7004 (10-50 microg/ml) exhibited significant metal chelation activity (p < 0.05), as compared to control, and maximum percentage inhibition (30%) of formation of iron-2,2'-bi-pyridyl complex was observed at 50 microg/ml, which correlated well with quercetin (34.9%), taken as standard. The reducing power of REC-7004 increased in a dose-dependent manner. The absorption unit value of REC-7004 was significantly lower (0.0183 +/- 0.0033) as compared to butylated hydroxy toluene, a standard antioxidant (0.230 +/- 0.091), confirming its high reducing ability. Superoxide ion scavenging ability of REC-7004 exhibited a dose-dependent increase (1-100 microg/ml) and was significantly higher (p < 0.05) than that of quercetin at lower concentrations (1-10 microg/ml), while at 100 microg/ml, both quercetin and REC-7004 scavenged over 90% superoxide anions. MTT assay in U87 cell line revealed an increase in percent survival of cells at doses between 25 and 125 microg/ml in case of drug + radiation group. In vivo evaluation of radio-protective efficacy in mice revealed that intraperitoneal administration of REC-7004 (maximally effective dose: 400 mg/kg b.w.) 30 min prior to lethal (10 Gy) total-body gamma-irradiation rendered 83.3% survival. The ability of REC-7004 to inhibit lipid peroxidation induced by iron/ascorbate, radiation (250 Gy) and their combination [i.e., iron/ascorbate and radiation (250 Gy)], was also investigated and was found to decrease in a dose-dependent manner (0.05-2 mg/ml). The maximum percent inhibition of formation of MDA-TBA complex at 2 mg/ml in case of iron/ascorbate, radiation (250 Gy) and both i.e., iron/ascorbate with radiation (250 Gy) was 53.78, 63.07, and 51.76% respectively and were found to be comparable to that of quercetin. REC-7004 (1 microg/ml) also exhibited significant anti-hemolytic capacity by preventing radiation-induced membrane degeneration of human erythrocytes. In conclusion, Rhodiola renders in vitro and in vivo radioprotection via multifarious mechanisms that act in a synergistic manner.

Radioprotection by plant products: present status and future prospects.

The development of radioprotective agents has been the subject of intense research in view of their potential for use within a radiation environment, such as space exploration, radiotherapy and even nuclear war. However, no ideal, safe synthetic radioprotectors are available to date, so the search for alternative sources, including plants, has been on going for several decades. In Ayurveda, the traditional Indian system of medicine, several plants have been used to treat free radical-mediated ailments and, therefore, it is logical to expect that such plants may also render some protection against radiation damage. A systematic screening approach can provide leads to identifying potential new candidate drugs from plant sources, for mitigation of radiation injury. This article reviews some of the most promising plants, and their bioactive principles, that are widely used in traditional systems of medicine, and which have rendered significant radioprotection in both in vitro and in vivo model systems. Plants and their constituents with pharmacological activities that may be relevant to amelioration of radiation-mediated damage, including antiemetic, antiinflammatory, antioxidant, cell proliferative, wound healing and haemopoietic stimulatories are also discussed.

Podophyllum hexandrum (Himalayan mayapple) extract provides radioprotection by modulating the expression of proteins associated with apoptosis.

Podophyllum hexandrum Royale (Himalayan mayapple), a high-altitude Himalayan plant, has been shown to provide over 80% whole-body radioprotection in mice. To investigate the radioprotective potential of P. hexandrum at the molecular level, expression patterns of various proteins associated with apoptosis were studied in the spleen of male Swiss albino strain A mice by immunoblotting. Treatment with P. hexandrum [200 mg/kg of body weight; an ethanolic 50% (w/v) extract delivered intraperitoneally] 2 h before irradiation resulted in MAPKAP (mitogen-activated protein kinase-activated protein) kinase-2 activation along with HSF-1 (heat-shock transcription factor-1), leading to up-regulation of HSP-70 (heat-shock protein-70) as compared with sham-irradiated (10 Gy) mice. Strong inhibition of AIF (apoptosis-inducing factor) expression was observed in the mice treated with P. hexandrum 2 h before irradiation as compared with the sham-irradiated group. Inhibition in the translocation of free NF-kappaB (nuclear factor kappaB) from cytoplasm to nucleus was observed upon P. hexandrum pretreatment 2 h before irradiation when compared with radiation-treated mice. P. hexandrum pre-treatment (2 h before irradiation) resulted in inhibition of NF-kappaB translocation, and the expression of tumour suppressor protein p53 was observed to be down-regulated as compared with sham-irradiated control. An increase in the expression of proteins responsible for cell proliferation [Bcl-2 (B-cell chronic lymphocytic lymphoma 2), Ras-GAP (Ras-GTPase-activating protein) and PCNA (proliferating cell nuclear antigen)] was observed in the P. hexandrum-pretreated irradiated mice as compared with sham-irradiated controls. Caspase 3 activation resulted PARP [poly(ADP-ribose) DNA polymerase] cleavage, and DNA degradation was strongly inhibited in the mice treated with P. hexandrm (+/-irradiation) as compared with the mice treated with radiation (+/-heat shock). The present study thus clearly demonstrated that P. hexandrum extract provides protection from gamma-radiation by the modulation of expression of proteins associated with cell death.

Radioprotection by Podophyllum hexandrum in the liver of mice: A mechanistic approach.

To evaluate radiation protection offered by the extract of Podophyllum hexandrum, expression of various cytoprotective proteins was studied using liver of Swiss albino Strain 'A' male mouse by immunoblotting. Induction of heat-shock factor-1 (HSF-1), led to up-regulation of heat-shock protein-70 (HSP-70) upon P. hexandrum (200mg/kg b. wt.; i.p. 50% ethanolic extract) treatment 2h before irradiation (10Gy) as compared to sham-irradiated control. Translocation of free nuclear factor kappa B (NFκB) from cytoplasm to nucleus was found to be inhibited upon P. hexandrum treatment. An increase in Bcl-2, proliferating cell nuclear antigen (PCNA) along with a decrease in p53, caspase-3, apoptosis inducing factor (AIF) expression was observed in the mice treated with P. hexandrum. The present study indicated that P. hexandrum extract provides protection from radiation by modulation of expression of the proteins associated with apoptosis.

Radioprotective and antioxidant properties of low-altitude Podophyllum hexandrum (LAPH).

The development of nontoxic yet effective radioprotectors is needed because of the increasing risk of human exposure to ionizing radiation. We have reported that high-altitude Podophyllum hexandrum (HAPH) confers a radioprotective effect in in vitro and in vivo models. The present study reports on the antioxidant and radioprotective properties of low-altitude Podophyllum hexandrum (LAPH), from which the toxic compound podophyllotoxin has been partially removed during the extraction process. Using HPLC,we estimated the relative content of two marker compounds, podophyllotoxin and podophyllotoxin glycoside, in low-altitude Podophyllum extract (LAPE) and found them to be 23.3% and 9.50%, respectively. The ferrous ion chelation potential of LAPE was estimated using the 2,2 bipyridyl assay, and the activity was found to be increased concomitantly with the increase in its concentration, with a maximal inhibition at 25 microg/mL (42.20%) as compared to quercetin (34.9%). The electron donation potential of LAPE was also evaluated, because the antioxidant activities of natural products are known to bear a direct correlation with their ability to donate electrons. The concentration required to attain unit absorbance values at 700 nm were 0.230541+/-0.09 and 0.041+/-0.06 for butylated hydroxyl toluene and LAPE, respectively, indicating a higher antioxidant activity of LAPE. The free radical scavenging ability of LAPE was also assessed and exhibited a dose-dependant increase (1-100 microg/mL), comparable to that of quercetin at 25 microg/mL. The role of LAPE in protecting DNA was evaluated, and it was found that LAPE (30 microg/mL) rendered its maximum radioprotection against the 250 Gy-induced damage in the plasmid (pBR322) relaxation assay. LAPE significantly inhibited radiation-induced, iron/ascorbate- and combined stress (iron/ascorbate and radiation)-induced formation of TBARS (p<0.05). We conclude that LAPH, with its easy accessibility, ease of cultivation, multifarious radioprotective properties, and role as a renewable source of bioactive constituents, along with its low associated toxicity (due to partial removal of podophyllotoxin), enhances its possible use for human clinical applications.

Radioprotective potential of an herbal extract of Tinospora cordifolia.

A preparation of Tinospora cordifolia (RTc) administered i.p. (200 mg/kg b.w.) to strain "A" male mice 1 h before whole body gamma-irradiation was evaluated for its radioprotective efficacy in terms of whole body survival, spleen colony forming units (CFU), hematological parameters, cell cycle progression, and micronuclei induction. Preirradiation treatment with RTc rendered 76.3% survival (30 days), compared to 100% mortality in irradiated control and prevented radiation induced weight loss. On 10th postirradiation day, the endogenous CFU counts in spleen were decreased with increasing radiation doses 12.0 (5 Gy), 2.16 (7.5 Gy) and 0.33 (10 Gy) but pre-irradiation administration of 200 mg/kg b.w. of RTc increased CFU counts to 31.16, 21.83 and 3.00 respectively. Pre-irradiation RTc treatment could restore total lymphocyte counts (TLC) by the 15th day to normal. It also increased the S-phase cell population that was reduced following 2 Gy irradiation in a time dependent manner. 2 Gy irradiation-induced micronuclei were also decreased by a pre-irradiation administration of RTc from 2.9 to 0.52%. Because the radioprotective manifestation of RTc observed in several systems in experimental animals can be exploited for human applications.