Saccharomyces boulardii as therapeutic alternative in experimental giardiasis

AIMS

The objective of this study was to evaluate the effect of treatment with the probiotic Saccharomyces boulardii with or without metronidazole in experimental giardiasis.

METHODS AND RESULTS

The effect of treatment with S. boulardii with or without metronidazole on the intestinal mucosa, the antioxidant defence system and the parasitic load was determined in experimental giardiasis. Eight groups of animals with infection and/or treatment with the probiotic and/or drugs for 1 week after infection with Giardia lamblia were used. A reduction of approximately 90% in the parasitic load was observed in all the treated groups. Saccharomyces boulardii attenuated the damage caused by infection in the intestinal mucosa preserving its architecture and inhibiting the oxidative stress induced by parasite and metronidazole.

CONCLUSIONS

Saccharomyces boulardii was effective alone or in combination with metronidazole in resolving already established G. lamblia infection.

SIGNIFICANCE AND IMPACT OF THE STUDY

These results suggest the use of S. boulardii as an alternative treatment for giardiasis mainly in cases of resistance or intolerance to conventional treatment.

Beneficial effects resulting from oral administration of Escherichia coli Nissle 1917 on a chronic colitis model

Inflammatory bowel diseases (IBD) are chronic processes involving a deregulated immune response against intestinal microbiota in genetically susceptible individuals. Ulcerative colitis (UC) is an IBD restricted to colonic mucosa and its chronicity is a predisposing factor for colorectal cancer (CRC). Probiotics have been investigated as an adjuvant treatment for UC, and Escherichia coli Nissle 1917 (EcN) was the focus of our investigation. The aim of this study was to investigate the preventive effect of the EcN probiotic in an experimental model of chronic colitis in germ-free (GF) and conventional (CV) mice. CV female mice were used for clinical, immunological and permeability experiments. GF mice were used for a faecal microbiota transplantation assay. To induce colitis, three cycles of 3.0% dextran sulphate sodium (DSS) were administered to the animals. For probiotic treatment, the mice received a daily intragastric gavage of 9.0 log₁₀ cfu of EcN, beginning 10 days before colitis induction and continuing until the end of the experiment. EcN presented beneficial effects when administered preventively. Daily Disease Activity Index (DAI) evolution demonstrated significant difference in remission periods after the first two DSS cycles and during the third one. Reduction in bacterial translocation after probiotic treatment indicated protection of the intestinal barrier. Associated with mucosal preservation, restoration of secretory immunoglobulin A levels and reduction of interleukin (IL)-5, IL-13, tumour necrosis factor and interferon-γ levels were observed in EcN treatment. Finally, when microbiota modification was verified, 16S rRNA-based compositional analysis showed variation of intestinal microbiota between the control and colitis groups. After faecal transplantation using GF mice, it was observed that EcN treatment in CV mice might result in modulated intestinal microbiota. This was observed indirectly in the reduced daily DAI, when colitis was compared with treated group. In conclusion, EcN presented beneficial effects in this model, suggesting its usefulness for treating UC.

Effect of probiotics on the maintenance of intestinal homeostasis after chemotherapy: systematic review and meta-analysis of pre-clinical studies

Gastrointestinal mucositis (GIM) is an inflammation caused by antitumor therapy, especially after chemotherapy and radiotherapy. Currently in the clinical practice, only palliative measures are taken to treat GIM, representing the main clinical limitation in the management of this condition. Several studies have highlighted the potential benefits of probiotics for the management of GIM, but the actual role of these microorganisms in the maintenance of intestinal homeostasis remains elusive. In this context, here we aimed to realise a systematic review with meta-analysis to evaluate the effect of probiotics on experimental GIM. The meta-analysis showed that probiotics significantly suppressed the body weight loss related to GIM in rodents (95% confidence interval (CI): -2.67 to -0.70; I²=98%, P<0.00). Subgroup analysis showed that pre-treatment (≥7 days before chemotherapy) (95% CI: -8.84 to -0.17; I²=98%, P<0.04) with a high dose of probiotics (≥ 10⁹ cfu/day) (95% CI: -2.58 to -0.28; I²=98%, P<0.00) comprising two or more microorganism species (95% CI: -6.49 to -0.28; I²=96%, P=0.03) remedied GIM more effectively. It was also revealed that fungi (specifically Saccharomyces boullardii) are more effective in remedying GIM than bacteria (P=0.03 vs P<0.00), and the mouse models are more receptive than rats to the enteroprotective effects of probiotics (95% CI: -4.76, -0.69; I²=97%, P=0.01). Qualitative analyses highlighted that probiotics suppress GIM through several mechanisms; they reduce the intestinal permeability, suppress the pro-inflammatory cytokine production while stimulating production and secretion of anti-inflammatory cytokines, inhibit the signalling pathways coupled to inflammation and apoptosis, accelerate the proliferation of enterocytes, reduce the levels of reactive oxygen species, and help maintain the protective mucus layer. In conclusion, this review highlights the therapeutic benefits of probiotics in experimental GIM.

Treatment with Bifidobacterium longum 51A attenuates intestinal damage and inflammatory response in experimental colitis

This study evaluated the effects of Bifidobacterium longum 5^1A on the intestinal mucosa and inflammatory response in experimental colitis. Colitis was induced by administration of 3.5% dextran sodium sulphate (DSS) solution for 7 days. Two periods of administration were performed: treatment (T) group, mice received Bifidobacterium only during disease induction (7 days); total treatment (TT) group, mice received Bifidobacterium for 10 days before and during disease induction. The probiotic effects on intestinal permeability, inflammatory infiltrate, histological analysis, cytokines, chemokines and sIgA were evaluated. Bifidobacterium administration in the T group showed reduction in intestinal permeability and lower IL-1β, myeloperoxidase, and eosinophil peroxidase levels compared to those in the colitis group (P<0.05). Bifidobacterium administration in the TT group attenuated severe lesions in the colon and reduced eosinophil peroxidase level (P<0.05). B. longum 5^1A treatment modality was more effective than total treatment and reduced the inflammatory response and its consequences on intestinal epithelium.

Technetium-99m-labeled lapachol as an imaging probe for breast tumor identification

OBJECTIVE

Breast cancer is a health problem worldwide with high incidence and mortality rates. It is well known that the development of more sensitive and specific diagnostic methods is of great importance since an early diagnosis is essential to successfully treat tumors. Lapachol is a natural compound, belonging to the naphthoquinone group that has been widely used in traditional medicine to treat various illnesses, including cancer. The aim of this study was to evaluate technetium-99m (^99mTc) labeled lapachol as an imaging probe for breast cancer identification.

METHODS

To achieve this purpose, lapachol was labeled with ^99mTc, radiochemical purity and in vitro stability were determined. Blood clearance, in healthy mice, and biodistribution, in 4T1 tumor-bearing mice, were also evaluated.

RESULTS

Lapachol was successfully labeled with ^99mTc, with high values of radiochemical yield (95.9±3.4%). In vitro stability showed that the radiolabeled complex remained stable for up to 24h, with values above 90% for both saline and plasma (95.6±3.6% and 96.4±1.7%, respectively). The radiolabeled complex decays in a biphasic manner, with a half-life of distribution and elimination equal to 3.3 and 50.0min, respectively. Biodistribution and scintigraphic images showed high uptake in organs of excretion (kidneys, liver, and intestine). It could be also noted that tumor uptake was higher than the muscle at all time points. Tumor-to-muscle ratio reaches ∼4.5 at 24h after administration.

CONCLUSION

These findings suggest that ^99mTc-lapachol can be a potential diagnostic agent for breast tumors.

Saccharomyces cerevisiae UFMG A-905 treatment reduces intestinal damage in a murine model of irinotecan-induced mucositis

Indigenous microbiota plays a crucial role in the development of several intestinal diseases, including mucositis. Gastrointestinal mucositis is a major and serious side effect of cancer therapy, and there is no effective therapy for this clinical condition. However, some probiotics have been shown to attenuate such conditions. To evaluate the effects of Saccharomyces cerevisiae UFMG A-905 (Sc-905), a potential probiotic yeast, we investigated whether pre- or post-treatment with viable or inactivated Sc-905 could prevent weight loss and intestinal lesions, and maintain integrity of the mucosal barrier in a mucositis model induced by irinotecan in mice. Only post-treatment with viable Sc-905 was able to protect mice against the damage caused by chemotherapy, reducing the weight loss, increase of intestinal permeability and jejunal lesions (villous shortening). Besides, this treatment reduced oxidative stress, prevented the decrease of goblet cells and stimulated the replication of cells in the intestinal crypts of mice with experimental mucositis. In conclusion, Sc-905 protects animals against irinotecan-induced mucositis when administered as a post-treatment with viable cells, and this effect seems to be related with the reduction of oxidative stress and preservation of intestinal mucosa.

Evaluation of (99m)Tc-HYNIC-βAla-Bombesin(7-14) as an agent for pancreas tumor detection in mice

Pancreatic adenocarcinoma is important in oncology because of its high mortality rate. Deaths may be avoided if an early diagnosis could be achieved. Several types of tumors overexpress gastrin-releasing peptide receptors (GRPr), including pancreatic cancer cells. Thus, a radiolabeled peptide derivative of gastrin-releasing peptide (GRP) may be useful as a specific imaging probe. The purpose of the present study was to evaluate the feasibility of using^99mTc-HYNIC-βAla-Bombesin_(7-14)as an imaging probe for Capan-1 pancreatic adenocarcinoma. Xenographic pancreatic tumor was developed in nude mice and characterized by histopathological analysis. Biodistribution studies and scintigraphic images were carried out in tumor-bearing nude mice. The two methods showed higher uptake by pancreatic tumor when compared to muscle (used as control), and the tumor-to-muscle ratio indicated that^99mTc-HYNIC-βAla-Bombesin_(7-14)uptake was four-fold higher in tumor cells than in other tissues. Scintigraphic images also showed a clear signal at the tumor site. The present data indicate that^99mTc-HYNIC-βAla-Bombesin_(7-14)may be useful for the detection of pancreatic adenocarcinoma.

Coconut water solutions for the preservation of spleen, ovary, and skin autotransplants in rats

BACKGROUND

The purpose of this study was to evaluate the efficacy of coconut water in the preservation of spleen, ovary, and skin autotransplantations in rats.

METHODS

Fifty female Wistar rats were divided randomly into 5 groups on the basis of the following tissue graft preservation solutions: group 1, lactated Ringer's; group 2, Belzer's solution; group 3, mature coconut water; group 4, green coconut water; and group 5, modified green coconut water. In group 5, the green coconut water solution was modified to obtain the same electrolyte composition as Belzer's solution. The spleen, ovaries, and a skin fragment were removed from each animal, stored for 6 hours in one of the solutions, and then re-implanted. The recoveries of tissue functions were assessed 90 days after surgery by means of spleen scintigraphy and blood tests. The implanted tissues were collected for histological analyses.

RESULTS

Higher immunoglobulin G levels were observed in the animals of group 5 than in the animals of group 1. Differences in follicle-stimulating hormone levels were observed between groups 1 and 2 (P < .001), between groups 4 and 2 (P = .03), and between groups 5 and 2 (P = .01). The spleen scintigraphy results did not differ among the groups. The ovarian tissue was better preserved in the mature coconut water group (P < .007).

CONCLUSIONS

Solutions containing coconut water allowed for the preservation of the spleen, ovaries, and skin for 6 hours, and the normal functions of these tissues were maintained in rats.

Activity and in vivo tracking of Amphotericin B loaded PLGA nanoparticles

The development of biocompatible polymeric nanoparticles has become an important strategy for optimizing the therapeutic efficacy of many classical drugs, as it may expand their activities, reduce their toxicity, increase their bioactivity and improve biodistribution. In this study, nanoparticles of Amphotericin B entrapped within poly (lactic-co-glycolic) acid and incorporated with dimercaptosuccinic acid (NANO-D-AMB) as a target molecule were evaluated for their physic-chemical characteristics, pharmacokinetics, biocompatibility and antifungal activity. We found high plasma concentrations of Amphotericin B upon treatment with NANO-D-AMB and a high uptake of nanoparticles in the lungs, liver and spleen. NANO-D-AMB exhibited antifungal efficacy against Paracoccidioides brasiliensis and induced much lower cytotoxicity levels compared to D-AMB formulation in vivo and in vitro. Together, these results confirm that NANO-D-AMB improves Amphotericin B delivery and suggest this delivery system as a potential alternative to the use of Amphotericin B sodium deoxycholate.

Digestion, Absorption and Tissue Distribution of Ovalbumin and Palmitoyl-ovalbumin: Impact on Immune Responses Triggered by Orally Administered Antigens

Previous work in this laboratory has demonstrated that ovalbumin coupled to palmitoyl residues (palmitoyl-Ova) does not induce oral tolerance. The present study sought to determine whether this coupling affects digestion, absorption and transfer of antigen. Ova and palmitoyl-Ova were shown to be digested differently in vitro by proteolytic enzymes and presented different tissue distribution kinetics after being labelled with (99m)technetium and orally administered to animals. Palmitoyl-Ova remained longer in the stomach, while native Ova was quickly transferred to the gut and other organs. After 3 h, higher levels of palmitoyl-Ova were found in the blood, Peyer's patches, mesenteric lymph nodes, liver and, especially, the spleen, which appears to be essential for immunization with palmitoyl-Ova. In fact, splenectomized mice treated orally with palmitoyl-Ova became tolerant, while tolerance to Ova was not affected. Thus, palmitoyl coupling was demonstrated to affect antigen digestion, absorption and transport. This is the first time that the spleen has been shown to be required for oral immunization with palmitoyl-Ova.

Age effects on the pharmacokinetics of tityustoxin from Tityus serrulatus scorpion venom in rats

The pharmacokinetics of scorpion venom and its toxins has been investigated in experimental models using adult animals, although, severe scorpion accidents are associated more frequently with children. We compared the effect of age on the pharmacokinetics of tityustoxin, one of the most active principles of Tityus serrulatus venom, in young male/female rats (21-22 days old, N=5-8) and in adult male rats (150-160 days old, N=5-8). Tityustoxin (6 microg) labeled with 99mTechnetium was administered subcutaneously to young and adult rats. The plasma concentration vs time data were subjected to non-compartmental pharmacokinetic analysis to obtain estimates of various pharmacokinetic parameters such as total body clearance (CL/F), distribution volume (Vd/F), area under the curve (AUC), and mean residence time. The data were analyzed with and without considering body weight. The data without correction for body weight showed a higher Cmax (62.30 +/- 7.07 vs 12.71 +/- 2.11 ng/ml, P<0.05) and AUC (296.49 +/- 21.09 vs 55.96 +/- 5.41 ng h(-1) ml(-1), P<0.05) and lower Tmax (0.64 +/- 0.19 vs 2.44 +/- 0.49 h, P<0.05) in young rats. Furthermore, Vd/F (0.15 vs 0.42 l/kg) and CL/F (0.02 +/- 0.001 vs 0.11 +/- 0.01 l h(-1) kg(-1), P<0.05) were lower in young rats. However, when the data were reanalyzed taking body weight into consideration, the Cmax (40.43 +/- 3.25 vs 78.21 +/- 11.23 ng kg(-1) ml(-1), P<0.05) and AUC (182.27 +/- 11.74 vs 344.62 +/- 32.11 ng h(-1) ml(-1), P<0.05) were lower in young rats. The clearance (0.03 +/- 0.002 vs 0.02 +/- 0.002 l h(-1) kg(-1), P<0.05) and Vd/F (0.210 vs 0.067 l/kg) were higher in young rats. The raw data (not adjusted for body weight) strongly suggest that age plays a pivotal role in the disposition of tityustoxin. Furthermore, our results also indicate that the differences in the severity of symptoms observed in children and adults after scorpion envenomation can be explained in part by differences in the pharmacokinetics of the toxin.

Assessment of the effect of Fucus vesiculosus extract on the labeling of blood constituents with technetium-99m and the histological modifications on the shape of the red blood cells

Natural products are widely used as food or food additives or medicines for humans. We are trying to develop a model to assess the possible toxic properties of natural products, such as Fucus vesiculosus, utilized in popular medicine. Red blood cells (RBC) labeled with technetium-99m (99mTc) are used in various procedures in nuclear medicine. This labeling procedure depends on a reducing agent, and stannous chloride is used. There is evidence that this labeling may be altered by drugs. We have investigated the possibility that F. vesiculosus extract is capable of altering the labeling of blood elements with 99mTc. Blood was incubated with F. vesiculosus extract and stannous chloride solution and Tc-99m added. Blood was centrifuged and plasma (P) and blood cells (BC) were isolated. Samples of P or BC were also precipitated, centrifuged and insoluble (IF) and soluble (SF) were separated. The percentages of radioativity (%ATI) in BC, IF-P and IF-BC were calculated. Histological preparations of the RBC treated with F. vesiculosus revealed that this extract is capable of promoting important modifications on the shape of the RBC. The%ATI decreased on BC from 93.6+/-2.3 to 29.0+/-2.7, on IF-P from 77.6+/-1.2 to 7.5+/-1.0 and on IF-BC from 80.0+/-3.4 to 12.6+/-4.8. Once the RBC labeling procedure with 99mTc depends on the presence of stannous (+2) ions, the substances present in the F. vesiculosus extract should increase the valence of these ions to stannic (+4). This would decrease the%ATI on blood elements and indicate the presence of oxidant agents in the F. vesiculosus extract.

Technetium-99m labeling of tityustoxin and venom from the scorpion Tityus serrulatus

The tityustoxin, the most toxic fraction from scorpion Tityus serrulatus venom, has been used as a tool in several neurochemical and neuropharmacological studies. Biological activities of labeled and unlabeled tityustoxin and venom were compared. The samples were labeled in the presence of stannous chloride and sodium borohydride with a yield of 60-70% for the venom and 75-85% for tityustoxin and then chromatographed in Sephadex G-10. Biological activities of tityustoxin and venom were preserved after labeling.

Assessment of inflammatory bowel disease by using two different (99m)Tc leucocyte labelling methods

The aim of this study was to retrospectively compare the diagnostic accuracy of (99m)Tc hexamethylpropyleneamine oxime (HMPAO) white blood cell scintigraphy in patients with a suspicion of active inflammatory bowel disease by using two different cell suspension media: leukocyte poor plasma (LPP) and Hanks' balanced salt solution (HBSS). Leukocytes from 30 patients were labelled using LPP and in 28 cases using HBSS. In the LPP method the leukocytes were resuspended in 0.5 ml cell-free plasma while in the HBSS method the cells were resuspended in 0.5 ml HBSS. Scintigraphic images were obtained at 30 min and 2 h after injection of 185-200 MBq (99m)Tc-HMPAO leukocytes. The leukocyte labelling efficiency was 65.5% and 89.0%, respectively, for the LPP and HBSS methods. There were 22 true positive, seven true negative and one false negative result in the LPP group, while in the HBSS group results were 18, nine and one, respectively. Diagnostic accuracy was similar with both methods although sensitivity was slightly higher in the HBSS group. In summary, these date indicate that leukocyte scintigraphy labelling using HBSS as the resuspension medium should be used as a first option for white blood cell labelling and diagnosis of inflammatory bowel disease.

Effect of extract of medicinal plants on the labeling of blood elements with Technetium-99m and on the morphology of red blood cells: I--a study with Paullinia cupana

Drugs can alter the labeling and the morphology of red blood cells. As Paullinia cupana is used in popular medicine, we evaluated its influence on the labeling process using technetium-99m (Tc-99m). Blood was incubated with P. cupana, stannous chloride and Tc-99m. Samples were centrifuged and plasma (P) and blood cells (BC) were separated and precipitated with trichloroacetic acid. Soluble (SF) and insoluble fractions (IF) were isolated. The morphology of the blood cells was evaluated under an optical microscope. The results showed a significant (P = 0.05) decrease in the uptake of radioactivity for the RBC (97.93 +/- 0.74 to 36.90 +/- 4.71%), in IF-P and in IF-BC due to P. cupana extract. The study of the morphology of the RBC revealed alterations in the shape of these cells. We suggest that the P. cupana effect could be explained by an inhibition of the stannous and pertechnetate ions or oxidation of the stannous ion or by damages in the plasma membrane.

Technetium-99m labeling anti-amastigote polyclonal antibodies of Leishmania amazonensis

Anti-amastigote polyclonal antibody (IgG) was incubated with solutions of stannous chloride and sodium borohidride. After that, 3.7 MBq of technetium-99m (99mTc) was added. A labeling yield of the antibody about 84% was obtained. After filtration of 99mTc-IgG, the radiochemical purity increased from 84 to 95%. The labeling of IgG with 99mTc did not modify the immunoreactivity of the antibody, since it was able to identify in vitro and in vivo the specific antigen of Leishmania amazonensis.

The effect of vincristine on the biodistribution of technetium-99m DTPA, GHA, and DMSA in Balb/c female mice

OBJECTIVE

Vincristine has been widely used in various chemotherapeutic protocols in oncology. The purpose of this study was to evaluate the effect of vincristine on the biodistribution of 99mTc-DMSA, 99mTc-GHA, and 99mTc-DTPA in Balb/c female mice.

METHODS

Vincristine (0.03 mg, 0.3 mL) was injected into female isogenic Balb/c mice (n = 15), in 3 doses over an interval of 96 h. The 99mTc-DMSA, 99mTc-GHA, or 99mTc-DTPA (7.4 MBq) was administered after the last dose of vincristine. After 0.5 h the animals were killed rapidly. The organs (pancreas, thyroid, brain, thymus, ovary, uterus, spleen, kidney, heart, stomach, lung, liver, bone, and lymph nodes) were isolated and the radioactivity in each organ was counted in a NaI(Tl) well counter. The percentage of radioactivity (%) in each was calculated and compared with the control group. Statistical analysis was performed by Wilcoxon test (P < 0.05).

RESULTS

The percentage of 99mTc-DMSA was increased in the lung, pancreas, heart, thyroid, brain, bone, and lymph nodes (inguinal and mesenteric). The percentage of 99mTc-GHA was decreased in the uterus, ovary, spleen, thymus, lymph nodes (inguinal and mesenteric), kidney, and heart. The percentage of 99mTc-DTPAwas increased in thymus, lymph nodes (inguinal and mesenteric), ovary, uterus, spleen, kidney, heart, stomach, lung, liver, and bone.

CONCLUSION

The results could be explained by the metabolization, toxic effect, therapeutic, or immunosupressive action of the studied chemotherapeutic drug.

Assessment of the effect of Maytenus ilicifolia (espinheira santa) extract on the labeling of red blood cells and plasma proteins with technetium-99m

We are trying to develop a model to assess properties of products utilized in popular medicine. Maytenus ilicifolia is used in herbal medicine. Red blood cells (RBC) labeled with technetium-99m (99mTc) are employed in nuclear medicine. This labeling procedure depends on a reducing agent and stannous chloride is used. There is evidence that this labeling may be altered by drugs. We have investigated the possibility of M. ilicifolia extract being capable to alter the labeling of blood elements with 99mTc. Blood was incubated with M. ilicifolia extract. Stannous chloride solution and Tc-99m were added. Blood was centrifuged and plasma (P) and blood cells (C) were isolated. Samples of P or C were also precipitated, centrifuged and insoluble (IF) and soluble (SF) were separated. The percentages of radioactivity (%ATI) in C, IF-P and IF-C was calculated. The %ATI decreased on C from 93.6+/-2.3 to 29.0+/-2.7, on IF-P from 77.6+/-1.2 to 7.5+/-1.0 and on IF-C from 80.0+/-3.4 to 12.6+/-4.8. Once in RBC labeling procedure with 99mTc depends on the presence of stannous (+2) ions, the substances of the M. ilicifolia extract could increase the valence these ions to stannic (+4). This fact would decrease the %ATI on blood elements and indicate the presence of oxidant agents in the M. ilicifolia extract.

99mTechnetium labelled Escherichia coli

Samples of a culture of unlabeled Escherichia coli were incubated with different concentrations of stannous chloride for various time periods. 99mTc (26.0 MBq) was added to each preparation and the results showed a labelling yield of 98% for E. coli. Since the bacterial viability of 99mTc-E. coli and E. coli did not show any statistical differences, these results demonstrate that labelling of E. coli with 99mTc does not modify the bacterial viability, and the radiolabelled bacteria may be a good model to study bacterial translocation.

Pharmacokinetic studies of 131I-stevioside and its metabolites

131I-STEVIOSIDE (1.10 MBq) was injected i.v in Wistar male rats, in distribution in the body and metabolism were studied. The highest concentration of radioactivity was observed in the liver and in the small intestine after 10 and 120 minutes, respectively. At 2 h after injection, the radioactivity eliminated in the bile was 52.0% of the original dose. The results of RP-HPLC analysis of the bile showed that stevioside was degraded in vivo and that steviol appeared as a major metabolite. However, in the urine; RP-HPLC analysis did not show the presence of steviol.

Detoxification of the T2 fraction from a scorpion (Tityus serrulatus, Lutz and Mello) venom by iodination and some immunogenic properties of the derivatives

The iodination of the T2 fraction abolished its lethal capacity, and doses up to 30 times the LD50 were injected i.p. in mice without noticeable toxic effects. The modified fraction retained its immunological properties. Antibodies generated against the iodinated T2 fraction were also reactive toward the native T2 fraction, T1 fraction and the whole soluble venom.