Combination therapy of N-acetyl-L-cysteine and S-2(2-aminoethylamino) ethylphenyl sulfide for sulfur mustard induced oxidative stress in mice.

INTRODUCTION: Sulfur mustard (SM) is chemically, bis(2-chloroethyl) sulfide and a strong alkylating agent that causes cytotoxicity and blisters on skin. In laboratory animal models, SM is extremely lethal. Since no specific antidote has been proposed, decontamination upon contact is the recommended procedure. Several antidotes have been screened for SM, and in that sulfanyl compounds, N-acetyl-l-cysteine (NAC) and S-2(2-aminoethylamino) ethylphenyl sulfide (DRDE-07) showed good protection. Since they showed protection at high doses, the aim of this study was to evaluate the efficacy in combination at low dose, for percutaneously administered SM in mice. MATERIAL AND METHODS: 4 LD50 of SM (32.4 mg/kg) was administered, and NAC (50 mg/kg), DRDE-07 (25 and 50 mg/kg) and their combinations were evaluated as 30 min pre-treatment by single oral administration. RESULT: After 72 h of SM exposure, significant decrease in body weight, decrease in hepatic reduced glutathione, and increase in hepatic malondialdehyde were observed (P < 0.001), showing oxidative stress. The combination of NAC (100 mg/kg) and DRDE-07 (50 mg/kg) showed significant protection (P < 0.01). The severe histopathological lesions induced by SM in liver, spleen and skin were also considerably reduced by the combination. CONCLUSION: The combination of NAC and DRDE-07 having sulfanyl groups, will be promising antioxidants and an effective antidote for SM toxicity.

Acute inhalation toxicity study of n-heneicosane and its combination with diflubenzuron: An attracticide of Aedes aegypti.

OBJECTIVE: Combination of an oviposition pheromone and an insect growth regulator for the control of vectors is an effective approach. There is a need for toxicological evaluation before its introduction. The present study evaluates the acute inhalation toxicity of n-heneicosane and its combination with diflubenzuron in a head-only inhalation exposure chamber made of glass. MATERIALS AND METHODS: A head-only inhalation exposure chamber made of glass (volume: 3.5 l) was used for exposing four rats at a time. A glass nebulizer was used for aerosolization of n-heneicosane and its combination with diflubenzuron (1:10 w/w). Nebulization pressure was 10 and 15 psi and the air flow of exposure the chamber was adjusted to 30 lpm. Male Wistar rats were acclimatized in whole body plethysmographs that were connected to volumetric flow pressure transducers by silicon tubes. The transducers were connected to an amplifier and a digitized response was recorded through an oscillograph and personal computers. Respiratory variables were recorded online. After inhalation exposure, various other parameters like survival, body weight, organ body weight index and biochemical changes were recorded for analysis. RESULTS AND DISCUSSION: Particle size determination proved that the aerosol particles were within the respirable range. LC50 of n-heneicosane and its combination with diflubenzuron was found to be more than 5 g/m3. There were minimal changes observed during exposure to n-heneicosane and also its combination with diflubenzuron on the respiratory variables. The changes were not consistent with the dose. CONCLUSION: n-Heneicosane and its combination with diflubenzuron showed low mammalian toxicity.

The genus Anogeissus: A review on ethnopharmacology, phytochemistry and pharmacology.

ETHNOPHARMACOLOGICAL RELEVANCE: The genus Anogeissus (axlewood tree, ghatti tree, button tree and chewing stick tree) belongs to Combretaceae, includes eight species that are distributed in Asia and Africa. Plants are used as an ethnomedicine in Asia and Africa to treat various ailments like diabetes, fever, diarrhoea, dysentery, tuberculosis, wound healing, skin diseases (eczema, psoriasis), snake and scorpion venom. Based on the traditional knowledge, different phytochemical and pharmacological activities have been at the focus of research. The aim of this review is to provide updated, comprehensive and categorized information on the ethnobotany, phytochemistry, pharmacological research and toxicity of Anogeissus species in order to identify their therapeutic potential and directs future research opportunities. MATERIALS AND METHODS: The relevant data was searched by using the keyword "Anogeissus" in "Scopus", "Google Scholar", "Web of Science", "PubMed", and "ScienceDirect" databases. Plant taxonomy was validated by the databases "The Plant List" and A.J. Scott, 1979. RESULTS: This review discusses the current knowledge of the ethnobotany, phytochemistry and in vitro as well as in vivo pharmacological evaluations carried out on the extracts and isolated main active constituents of Anogeissus genus. Among eight species, most of the phytochemical and pharmacological studies were performed on four species. About 55 secondary metabolites are isolated from the genus. Stem bark, leaf, seed, fruit, root of the plants are used for the treatment of several health disorders such as diabetes, fever, diarrhoea, dysentery, tuberculosis, wound healing, skin diseases (eczema, psoriasis), snake and scorpion venom. Gum ghatti obtained from Anogeissus latifolia is used after delivery as tonic and in spermatorrhoea. Many phytochemical investigations on this genus confirmed that it is rich in phenolic compounds. Modern pharmacology research has confirmed that the crude extracts or the isolated active compounds of the genus Anogeissus possess antioxidant, antimicrobial, wound healing, antiulcer, anti-inflammation, anti-diabetics, hepatoprotective, hypolipidemic, antiparasitic and neuroprotective effects. CONCLUSIONS: This review confirms that some Anogeissus species have emerged as a good source of the traditional medicine for wound healing, inflammation, skin diseases, microbial infection and diabetes. Many traditional uses of Anogeissus species have now been validated by modern pharmacology research. Intensive investigations of all the species of Anogeissus regarding phytochemical and pharmacological properties, especially their mechanism of action, safety and efficacy could be the future research interests before starting clinical trials.

A convenient first aid kit for chemical and biological agents and for radiation exposure.

The chemical and biological warfare agents are extremely toxic in nature. They act rapidly even in very small quantities and death may occur in minutes. Hence, physical and medical protection must be provided immediately to save life or avoid serious injury. A first aid kit has thus been developed for providing immediate relief from chemical and biological warfare agents (FAKCBW) with the objective of easy detection, personal decontamination, antidote for chemical warfare agents (like nerve agents, sulphur mustard, phosgene, cyanide, radiation exposure and bacterial agents), along with basic medication aid for pain, fever and inflammation. The kit box also includes a user friendly handbook with a simple standard operating procedure. In addition, the kit is rugged to withstand normal jerks, vibration and is water-proof.

Acute toxicity studies of safer and more effective analogues of N,N-diethyl-2-phenylacetamide.

The present work was designed to evaluate the toxicity of various synthesized aromatic amides that are analogs of N,N-diethyl-2-phenylacetamide, a well known insect repellent. The toxicity profile of these compounds was compared with N,N-diethyl-2-phenylacetamide as well as other registered insect repellents namely N,N-diethyl-3-methyl benzamide and N,N-diethylbenzamide. The primary skin irritation index values of the compounds, dermal toxicity of the chemicals and acute oral toxicity data to assess the safety of the synthesized aromatic amides are reported in this paper. Results of hematological and biochemical studies of these analogues are reported and discussed.

Acute and sub-acute toxicity of an insect pheromone, N-heneicosane and combination with insect growth regulator, diflubenzuron, for establishing no observed adverse effect level (NOAEL).

Aedes aegypti mosquito is one of the most notorious vectors of dangerous diseases like dengue hemorrhagic fever and chikangunya. One method of control of the vectors is by the use of semiochemicals or pheromones. The pheromone n-heneicosane (C21) has been proved to be effective in attracting the female Aedes aegypti to lay eggs in the treated water and the growth of the larva is controlled by insect growth regulator diflubenzuron (DB). This study was planned to assess the safety of C21 alone and the combination with DB. Acute toxicity tests were carried out using two doses, viz., 1600 and 3200 mg/kg and two routes of exposure oral and intra-peritoneal. Dermal toxicity test was carried out in both male and female rats at the dose of 3200 mg/kg. Primary skin irritation test was carried out in rabbits. Sub-acute (90 days) dermal toxicity studies in male and female rats at the dose of 1 and 2 mg/kg via the per-cutaneous route were also studied. Sub-acute (90 days) toxicity test through the oral route was carried out, at doses 125, 250 and 500 mg/kg in male and female rats. The calculated LD50 by ip route and dermal route was more than 5 g/kg in mouse and rats of both the sexes. In the primary skin irritation test no significant changes were noted. In the sub-acute toxicity studies even 500 mg/kg dose was not able to produce toxic response in rats when they were dosed daily for 90 days. The established no observed adverse effect level (NOAEL) was more than 500 mg/kg.

Prophylactic efficacy of combination of DRDE-07 and its analogues with amifostine against sulphur mustard induced systemic toxicity.

Sulphur mustard, [bis (2-chloroethyl)] sulphide (SM), is a bifunctional alkylating agent. SM forms sulphonium ion in the body which alkylates DNA and several other macromolecules, and induces oxidative stress. Although several antidotes have been screened for the treatment of systemic toxicity of SM in experimental animals none of them are recommended so far. In the search for more effective and less toxic antidotes, various combinations were tried against SM induced toxicity and skin lesions. SM exposed through percutaneous route was used to evaluate the prophylactic efficacy of various combinations. Low dose of DRDE-07 (S-2(2-aminoethylamino) ethyl phenyl sulphide), DRDE-30 [S-2(2-aminoethyl amino) ethyl propyl sulphide], DRDE-35 [S-2(2-aminoethyl amino) ethyl butyl sulphide] with amifostine combinations, were given orally 30 min prior to SM exposure. Significant depletion was observed in body weight, organ body weight index and hepatic GSH and GSSG content in mice after SM exposure. Pretreatment with low dose of different combinations of DRDE-07, DRDE-30 and DRDE-35 with amifostine could recover biochemical alterations and histopathological changes caused by SM exposures.

Comparative effects of pyrolytic products of fiber reinforced plastic and wood shavings on the respiratory variables in mice.

Comparative inhalation toxicity studies of pyrolytic products (smoke) from synthetic polymer, fiberglass reinforced plastic (FRP) and teak wood shavings were carried out in male Swiss albino mice. The breathing pattern and the respiratory variables were monitored using a computer program that recognizes the modifications of the respiratory pattern. Exposure to the smoke from both the polymers caused a concentration dependent decrease in normal breathing and an increase in sensory irritation measure. The acute lethal concentration 50 values for a 15 min static inhalation exposure to the smoke from FRP and teak wood shavings were found to be > 200.00 and 62.99 g/m(3), respectively. Hence the inhalation toxicity of smoke from FRP sample on a mass basis is approximately one-third that of the smoke from teak wood. The concentration of smoke causing 50% respiratory depression of the exposed animals were found to be 6.877 and 0.106 g/m(3) for FRP and teak wood samples, respectively. Thus the sensory irritancy of the smoke from FRP sample is approximately 65 times lesser than the smoke from teak wood. The higher sensory irritancy potential of wood smoke as compared to FRP smoke may be caused by a greater number of submicron particles (size range of 2 micron and less) and greater percentage of gases present in wood smoke as compared to FRP smoke. Thus in case of accidental fires, synthetic polymers like FRP may be a safer choice for structural parts and interiors than the natural wood.

Ameliorative effect of DRDE 07 and its analogues on the systemic toxicity of sulphur mustard and nitrogen mustard in rabbit.

Despite extensive research efforts, there is no unanimous approval of any animal model to evaluate the toxicity of sulphur mustard [SM; bis (2-chloroethyl) sulphide] or nitrogen mustard [HN-3; tris-(2-chloroethyl) amine] and screening of various prophylactic and therapeutic agents against them. In this study, differential toxicity of mustard agents in higher animal model that is male rabbit was determined. Protective efficacy of DRDE 07 [S-2(2-aminoethylamino) ethyl phenyl sulphide] and its analogues were also evaluated against SM and HN-3 toxicity. Differential toxicity study of SM and HN-3 reveals that both the compounds were more toxic by percutaneous route as compared to subcutaneous route. Till date, there is no recommended drug to counteract SM induced toxicity or mortality in vivo. However, DRDE 07 (an amifostine analogue) and its analogues are found to be very effective protective agents against percutaneously exposed SM in rabbits. The present experiments also showed that SM does not cause skin injury alone but also can cause systemic toxicity as well. DRDE 07 and many of its analogues may prove as prototype compounds for the development of better prophylactic and therapeutic drugs to counter the toxicity of SM or HN-3. In conclusion, rodents and rabbits can be used for the screening of drugs against the blistering agents.

DRDE-07 and its analogues as promising cytoprotectants to nitrogen mustard (HN-2)--an alkylating anticancer and chemical warfare agent.

Nitrogen mustard (HN-2), also known as mechlorethamine, is an alkylating anticancer agent as well as blister inducing chemical warfare agent. We evaluated the cytoprotective efficacy of amifostine, DRDE-07 and their analogues, and other antidotes of mustard agents against HN-2. Administration of 1 LD(50) of HN-2 (20mg/kg) percutaneously, decreased WBC count from 24h onwards. Liver glutathione (GSH) level decreased prominently and the maximum depletion was observed on 7th day post-HN-2 administration. Oxidised glutathione (GSSG) level increased significantly at 24h post-administration and subsequently showed a progressive decrease. Hepatic malondialdehyde (MDA) level and percent DNA damage increased progressively following HN-2 administration. The spleen weight decreased progressively and reached a minimum on 3-4 days with subsequent increase. The antidotes were administered repeatedly for 4 and 8 days after percutaneous administration of single sublethal dose (0.5 and 0.25 LD(50)) of HN-2. Treatment with DRDE-07, DRDE-30 and DRDE-35 significantly protected the changes in spleen weight, WBC count, GSH, GSSG, MDA and DNA damage following HN-2 administration (0.5 and 0.25 LD(50)). There was no alteration in the transaminases (AST and ALT), and alkaline phosphatase (ALP) activities, neither with HN-2 nor with antidotes. The present study shows that HN-2 is highly toxic by percutaneous route and DRDE-07, DRDE-30 and DRDE-35 can partially protect it.

Comparative evaluation of some flavonoids and tocopherol acetate against the systemic toxicity induced by sulphur mustard.

OBJECTIVE: To evaluate the protective value of quercetin, gossypin, Hippophae rhamnoides (HR) flavone and tocopherol acetate against the systemic toxicity of percutaneously administered sulphur mustard (SM) in mice. MATERIALS AND METHODS: Quercetin, gossypin, HR flavone or tocopherol acetate (200 mg/kg, i.p.) were administered just before percutaneous administration of SM and protection against the SM lethality was evaluated. In another experiment quercetin, gossypin, HR flavone or tocopherol acetate were administered against 2 LD(50) SM. The animals were sacrificed seven days post SM administration and various biochemical parameters were estimated. RESULTS: The protection against the lethality of SM was very good with the flavonoids (quercetin = 4.7 folds; gossypin = 6.7 folds and HR flavone = 5.6 folds), compared to no protection with tocopherol acetate (0.7 fold). SM (2 LD(50)) showed decrease in reduced and oxidised glutathione (GSH and GSSG) levels, and an increase in malondialdehyde level (MDA). Oxidative stress enzymes like glutathione peroxidase, glutathione reductase and superoxide dismutase were significantly decreased. The total antioxidant status was also significantly decreased. Additionally, there was a significant increase in red blood corpuscles and hemoglobin content. All the flavonoids significantly protected the GSH, GSSG and MDA, and also the hematological variables. Tocopherol acetate failed to offer any protection in those parameters. Gossypin protected glutathione peroxidase, while HR flavone protected both glutathione reductase and glutathione peroxidase significantly. The decrease in body weight induced by SM and the histological lesions in liver and spleen were also significantly protected by the flavonoids but not by tocopherol acetate. CONCLUSION: The present study supports that SM induces oxidative stress and flavonoids are promising cytoprotectants against this toxic effect.

Prophylactic effect of gossypin against percutaneously administered sulfur mustard.

OBJECTIVE: To evaluate the protective efficacy of gossypin (3,3',4',5,7,8-hexahydroxyflavone 8-glucoside) by administering it intraperitoneally, for dose, time, and vehicle dependent effects against sulphur mustard (SM), administered through percutaneous route in mice. METHODS: SM (diluted in PEG-300) was administered percutaneously. The protective efficacy of gossypin was evaluated by administering it intraperitoneally (50, 100, 200, and 400 mg/kg), in various vehicles (water, PEG-300 and DMSO), and time intervals (30 min prior, simultaneous and 2 h post). The time dependent protection of gossypin (200 mg/kg in PEG-300; i.p.) was also evaluated using selected biochemical variables (GSH, GSSG, MDA, total antioxidant status, Hb, WBC count, RBC count, glutathione peroxidase, glutathione reductase, and superoxide dismutase) and liver histology. The protection of gossypin by oral route was also evaluated against percutaneously administered SM. RESULTS: The protection against systemic toxicity of SM (LD50 8.1 mg/kg) was better when gossypin was given with PEG-300 (8.0 folds) than DMSO (5.7 folds). No protection was observed when gossypin was administered with water. Good protection (8.0 folds) was observed when gossypin was administered (200 mg/kg in PEG-300; i.p.) at 30 min prior or simultaneous to SM exposure, but no protection was observed when gossypin was administered 2 h post to SM exposure. A significant weight loss was observed 7 days after SM administration (2 LD50), with a significant increase in RBC and Hb. A significant decrease in total antioxidant status of plasma, liver GSH and GSSG levels, and in the activities of glutathione peroxidase, glutathione reductase and superoxide dismutase was also observed 7 days after SM administration. SM treated mouse liver also showed necrosis. A significant protection was observed when gossypin (200 mg/kg in PEG-300; i.p.) was administered either as a pretreatment (30 min before) or simultaneous treatment, and not as a post treatment (2 h). The protective efficacy of gossypin was better through oral route when administered with DMSO (4.8 folds) than with PEG-300 (2.4 folds). No protection was observed when gossypin was administered orally with water. CONCLUSION: Percutaneous administration of SM induces oxidative stress and gossypin can protect it as a prophylactic agent by intraperitoneal or oral routes.

Protective effect of ethanolic and water extracts of sea buckthorn (Hippophae rhamnoides L.) against the toxic effects of mustard gas.

Ethanolic extract of H. rhamnoides L. leaf (HL-EOH), water and ethanolic extract of H. rhamnoides fruit (HF-W and HF-EOH), and H. rhamnoides flavone from fruit (HR-flavone) were evaluated against percutaneously administered sulphur mustard (SM), a chemical warfare agent. The animals administered with SM (9.7, 19.3 and 38.7 mg/kg) died at various days depending upon the dose and there was a significant reduction in the body weight. The H. rhamnoides extracts (1 g/kg; 3 doses; po) significantly protected the lethality, with a protective index of 2.4, 1.7, 1.7 and 2.2 for HL-EOH, HF-W, HF-EOH and HR-flavone respectively. Reduced glutathione (GSH) and oxidized glutalthione (GSSG) levels were reduced, and malondialdehyde (MDA) was elevated after percutaneous administration of SM. Oral administration of HL-EOH and HR-flavone significantly protected the body weight loss. Recovery in the levels of GSH, GSSG and MDA were also observed following oral administration of HL-EOH and HR-flavone. All the extracts were non-toxic and the LD50 was more than 5 g/kg. The present study shows that percutaneous administration of SM induces oxidative stress and ethanolic extract of leaf of H. rhamnoides and H. rhamnoides flavone from fruit can significantly protect it.

Differential toxicity of sulfur mustard administered through percutaneous, subcutaneous, and oral routes.

Sulfur mustard (SM), chemically 2,2'-dichloro diethyl sulphide, is an incapacitating and extremely toxic chemical warfare agent. It causes serious blisters on contact with human skin. While screening various antidotes against its toxicity, we observed that SM was more toxic through percutaneous (p.c.) route compared to oral (p.o.) and subcutaneous (s.c.) routes. The LD(50) of SM in female mice was found to be 5.7, 8.1 and 23.0 mg/kg through p.c., p.o., and s.c. routes, respectively. The body weight of the animals was monitored and it was found that percentage body weight loss was more in the p.c. route. There was significant DNA fragmentation in liver in all the three routes evaluated at 19.3 mg/kg dose of SM. The depletion of hepatic GSH content was found to be more in the p.c. route of exposure compared to s.c. route. There was significant reduction in WBC count in all the three routes of exposure. Histopathological evaluation of lung, liver, and spleen also showed that the damage was more in the p.c. route and severity of lesions was dependent on the dose of exposure. The most affected organ was liver by all the three routes. LD(50) was also determined in male rats and it was found to be 2.4, 2.4, and 3.4 mg/kg through p.c., p.o. and s.c. routes respectively. Since skin contains maximum number of metabolically active and rapidly dividing cells, differential metabolism of SM cannot be ruled out. Probably, this is the first report of a chemical showing more toxicity through p.c. route compared to s.c. route.