| || Effect of ricin on some biochemical haematological and histopathological variables in mice
Author : Om Kumar, K;Sugendran, K.;Pant, S. C.;Vijayaraghavan, R.
Source : Defence Science Journal ; Vol:54(4) ; 2004 ; pp 493-502
Subject : 57.089 Biomedical Sciences ;57 Biological Sciences ;61 Medical Sciences
Keywords : Ricin;Intraperitoneal route;Oral route;Toxicity;Leukocytosis;Median lethal concentration;Uric acid;Piloerection;Mice;Proteineous toxin
Abstract : Acute toxicity studies of ricin were carried out in Swiss albino male mice. The median lethal concentration (LD50) values were determined for mice through intraperitoneal and oral routes and were found to be 1.01 mg/kg and 28.29 mg/kg, respectively. The ricin (1.0 LD50) was administered in mice through intraperitoneal route and various toxicity related clinical variables were studied on the 1st, 3rd, and the 7th day of post-exposure. The prominent symptoms before death, were diarrhoea with black sticky vent and piloerection. The body weight decreased significantly in a dose-dependent manner. No significant change was observed in organ-to-body weight ratio on the 1st, 3rd, and the 7th day of post-exposure except kidney weight. On the 7th day, kidney weight increased significantly. The levels of blood urea, uric acid, and glucose increased, while total protein level decreased. However, activities of transaminase and phosphatases were not altered. Leukocytosis was also observed. The ricin also affected blood coagulation parameters. There was a significant increase in the clotting time. However, prothrombin time, bleeding time, and erythrocyte sedimentation rate were not altered. Histopathological studies showed degenerative changes in various visceral organs, viz, lungs, liver, spleen, kidney, and testis. Acute toxicity studies of ricin revealed that it is a highly toxic toxin. The ricin intoxication caused alterations in biochemical, haematological variables, and degenerative changes in various visceral organs.
| || Purification and biochemical characterisation of Ricin from castor seeds
Author : Kumar, Om;Nashikkar, A. B. ;Jayaraj , R.;Vijayaraghavan, R.;Prakash, A. O.
Source : Defence Science Journal ; Vol:54(3) ; 2004 ; pp 345-351
Subject : 66 Chemical Technology
Keywords : Ricin;Castor seeds;Purification;Gel filtration;Polyacrylamide gel electrophoresis;Western blot analysis;Blotting;Heamagglutination;SDS-PAGE;Ricinus communis
Abstract : "Ricin is a highly toxic plant toxin of Ricinus communis seeds, commonly known as castor seeds. The toxin was extracted and purified using affinity and size exclusion chromatography. The purity of ricin was evaluated by the sodium dodecylsulphate-polyacrylamide gel electrophoresis. Purified ricin gives a single band under non-reduced condition and two bands under reduced condition. The molecular weight of ricin was 65,0000 approx. The subunit structure of ricin on treatment with b-mercaptoethanol (1%) at molecular level revealed that the reducing agent converts ricin into two peptides. The molecular weight of these two peptides was estimated to be 34000 and 32000. The western-blot analysis revealed two dots for its two peptides in 29 kDa to 36 kDa regions. The heamagglutination titres for ricin and Ricinus communis agglutinins were 1:8 and 1:256. The purity of purified ricin was further confirmed by the electrophoresis and the western-blot analysis. The Indian variety of castor seeds, known as Ricinus communis used in this study, contains approx. 0.12 percent ricin. "
| || Biohazards of Protein Biotoxins
Author : Patocka, Jiri;Hon, Zdenek;Streda, Ladislav;Kuca, Kamil ;Jun, Daniel
Source : Defence Science Journal ; Vol:57(6) ; 2007 ; pp 825-837
Subject : 60 Biotechnology;61 Medical Sciences
Keywords : Biotoxin;Bioterrorism;Toxic protei;Ricin;Abrin;Viscumin;Volkenesin;Modeccin;Clostridium perfringens toxins;Mid-spectrum agents;Toxin
Abstract : Biotoxins are toxic substances produced by a living organism that cause diseases in human beings, animals, or plants. The agent may be lethal or incapacitating. The new, emerging threat agents are biotoxins produced by animals, plants, fungi, and bacteria. Many types of organisms produce substances that are toxic to humans. Examples of such biotoxins are botulinum toxin, tetanus toxin, and ricin. Several bioactive molecules produced by the pharmaceutical industry can be even more toxic than the classical chemical warfare agents. Such new agents, like the biotoxins and bioregulators, often are called mid-spectrum agents. The threat to human beings from agents developed by modern chemical synthesis and by genetic engineering also must be considered, since such agents may be more toxic or more effective in causing death or incapacitation than classical warfare agents. By developing effective medical protection and treatment against the most likely chemical and mid-spectrum threat agents, the effects of such agents in a war scenario or following a terrorist attack can be reduced. Toxin-mediated diseases have made human beings ill for millennia. The use of biological agents as weapons of terror has now been realised, and separating naturally occurring disease from bioterroristic events has become an important public health goal.
| || Detection of Ricin in Water Samples using Disposable Screen-Printed Electrodes
Author : Suresh, S.;Om Kumar;Kolhe, Pawan;Rao, V. Kameswara;Sekhar, K.
Source : Defence Science Journal ; Vol:57(6) ; 2007 ; pp 839-844
Subject : 60 Biotechnology;61 Medical Sciences
Keywords : Screen-printed electrode;Amperometric immunosensor;Ricin;Ppotentiostat;Plant toxin;ELISA
Abstract : Ricin is a highly toxic plant toxin, which is extracted from the beans of the castor plant, Ricinus communis. Ricin is thousand times more poisonous than cyanide and thirty times more potent than nerve gases. The toxin (ricin) could be used to contaminate food or water, causing panic. Attempts were made for the detection of ricin in water samples by utilising amperometric immunosensors. Single-use screen-printed electrodes were made using polystyrene and graphite. These electrodes were tested for their ability to detect 1-naphthol which is the product of the reaction between 1-naphthyl phosphate and the enzyme alkaline phosphatase conjugate. An indirect enzyme-linked immunosorbent assay (ELISA) system was used to detect ricin. First, ricin antigen was incubated on the screen-printed electrode. This was followed by blocking with BSA and incubation with antibody raised against ricin in rabbit. The last step wass the incubation with anti-antibody of rabbit conjugated to enzyme alkaline phosphatase. This electrode is inserted in an electrochemical cell containing diethanolamine buffer and a potential of 0.4 V wrt reference electrode (Ag/AgCl) was applied using a potentiostat. Various experiments were carried out for optimising the conditions like substrate concentration, amount of antibody raised against ricin, anti-antibody alkaline phosphatase conjugate, and blocking agents. It was found that the response of amperometric sensor is proportional to the logarithmic of ricin concentration from 100 ng/ml to 3200 ng/ml. Using traditional methods, it is possible to detect ricin concentration up to 300 ng/ml in 18 h, while with amperometric immunosensor, one can detect ricin as low as 40 ng/ml within 90 min. The details of making the screen-printed electrodes, characterisation, optimisation of various conditions for the highest sensitivity have been discussed.
| || Rapid detection of ricin by sensitising carboxylated latex particles by ricin antibodies
Author : Kumar, Om;Rai, G.P.;Parida, M.M;Vijayaraghavan, R.
Source : Defence Science Journal ; Vol:54(1) ; 2004 ; pp 57-63
Subject : 57 Biological Sciences ;57.089 Biomedical Sciences
Keywords : Ricin;Sensitised latex particles;Immunisation protocol;Immunogenic glycoprotein;Latex agglutination test
Abstract : Ricin is a highly toxic glycoprotein of Ricinus communis seeds, The toxin was purified and antisera was raised against ricin in rabbit. Polyclonal antibodies were covalently coupled through a water soluble carbodiimide to carboxylated latex particles in various concentrations (800 fig to 3200 (ig protein/0.5 ml). Maximum antibodies binding was obtained at 2400 Jig to 3200 jig protein/0.5 ml of 2 per cent (wt/vol) latex particles with a sensitivity of 200 Jig toxin per test (9 fig/ml). The sensitivity of latex agglutination test increased as amount of protein bound to the latex particles increased. The optimum sensitivity of test was recorded when latex particles were sensitised with 2800 ng protein/0.5 ml of latex particles. The reagents were stable for one year without loss of its sensitivity. Developed latex agglutination test is rapid, sensitive, and also does not require trained personnel and costly equipment.