The trypsin inhibitor pro-peptide induces toxic effects in Indianmeal moth, Plodia interpunctella.

The inhibitory potential of an inhibitor peptide based on the pro-region of trypsin zymogen was investigated in Indianmeal moth, P. interpunctella, which is a world-wide insect pest of stored food. Five peptides were designed based on molecular docking simulations. The designed peptide with the best score was selected and synthesized for further screening in vitro and in vivo. The peptide was characterized and its inhibitory effects towards the insect trypsin were evaluated and the kinetic analysis revealed a competitive type of inhibition against the target enzyme. The results showed that the peptide could successfully suppress the pest midgut trypsin, and more interestingly, it did not show considerable inhibitory effects on a mammalian trypsin. We also aimed to assess the effect of dietary insect meal treated with different concentrations of the peptide and observed a significant growth and development retardation in pupa and adult insects fed with the inhibitor peptide. The outcomes of the present study suggest an efficient inhibitor peptide that could specifically bind the P. interpunctella trypsin and inhibit its activity, which would be safe against human being health and environment. Notably, this is the first report on in vivo assessment of the direct effect of a pro-region as the specific inhibitor in development as well as survival of the pest insect. Furthermore, our findings could be a promising for future designed pesticides used in pest management.

Expression and purification of the trypsin inhibitor from tartary buckwheat in Pichia pastoris and its novel toxic effect on Mamestra brassicae larvae.

The gene of the trypsin inhibitor of tartary buckwheat (Fagopyrum tataricum) was successfully cloned, expressed in Pichia pastoris and tested for regulatory effects on insect growth. The three significant factors were optimized by single-factor experiments and central composite design in response surface methodology. Proteins were efficiently expressed at levels of 489.6-527.4 U/mg in shaken flasks. The trypsin inhibitor from tartary buckwheat (FtTI) was purified by affinity chromatography and centrifugal ultrafiltration. The purified FtTI efficiently inhibited trypsin protease activity by competitive inhibition with a Ki value 1.5 nM. The molecular mass of the purified protein was approximately 13.8 kDa. FtTI had a higher toxic killing effect on Mamestra brassicae larvae. The median lethal concentration for the larvae was 15 µg/mL.

Bio-potency of a 21 kDa Kunitz-type trypsin inhibitor from Tamarindus indica seeds on the developmental physiology of H. armigera.

A trypsin inhibitor purified from the seeds of Tamarindus indica by Sephadex G-75, DEAE-Sepharose and Trypsin-Sepharose CL-4B columns was studied for its antifeedant, larvicidal, pupicidal and growth inhibitory activities against Helicoverpa armigera larvae. Tamarindus trypsin inhibitor (TTI) exhibited inhibitory activity towards total gut proteolytic enzymes of H. armigera (~87%) and bovine trypsin (~84%). Lethal doses which caused mortality and weight reduction by 50% were 1% w/w and 0.50% w/w, respectively. IC50 of TTI against Helicoverpa midgut proteases and bovine trypsin were ~2.10 µg/ml and 1.68 µg/ml respectively. In larval feeding studies the 21 kDa Kunitz-type protein was found to retard growth and development, prolonged the larval-pupal development durations along with adversely affecting the fertility and fecundity of H. armigera. In artificial diet at 0.5% w/w TTI, the efficiency of conversion of ingested food as well as of digested food, relative growth rate, growth index declined whereas approximate digestibility, metabolic cost, relative consumption rate, consumption index and total developmental period enhanced for H. armigera larvae. These results suggest that TTI has toxic and adverse effect on the developmental physiology of H. armigera and could be useful in controlling the pest H. armigera.

Two-year carcinogenicity studies with the oral direct thrombin inhibitor ximelagatran in the rat and the mouse.

The results of 18 months mouse and 24 months rat carcinogenicity studies with the oral direct thrombin inhibitor ximelagatran are presented. In the mouse, gavage doses of ximelagatran up to 180 µmol/kg per d produced no neoplastic changes in any of the tissues examined. In the rat, gavage doses up to 240 µmol/kg per d produced multiple macroscopically detectable nodules in the pancreas, which are seen to be focal/multifocal acinar cell hyperplasia and focal/multifocal acinar cell adenoma upon histological evaluation. There were no other treatment-related effects on tumor incidence or distribution in the rat. The studies show a clear species difference in pancreatic effects between the rat and the mouse to long-term treatment with ximelagatran.

[Large-scale purification and acute toxicity of cowpea trypsin inhibitor].

OBJECTIVE: To provide the acute toxicity data of cowpea trypsin inhibitor (CpTI) using recombinant protein purified from E. coli. METHODS: Recombinant CpTI protein was expressed and purified from E. coli. Bacterial recombinant plasmid was transformed into E. coli and the transformed cells were induced with IPTG. The expressed CpTI protein was purified by hydrophobic interaction chromatography and anion exchange chromatography. Sixty mice, randomly assigned to 6 groups, were administrated 10.0, 4.64, 2.15 and 1.00 g/kg BW of CpTI or 5.00 g/kg BW of BSA control protein or sterile water respectively by oral gavage. RESULTS: All animals survived with no significant change in body weight and food consumption throughout the study. Macroscopic necropsy examination on day 15 revealed no gross pathological lesions in any of the animals. The maximum tolerated dose (MTD) of CpTI was more than 10.0 g/kg body weight in mice. CONCLUSION: No toxicity of CpTI protein was found in ICR mice model.

Evaluation of the In Vivo Acute Toxicity and In Vitro Hemolytic and Immunomodulatory Activities of the Moringa oleifera Flower Trypsin Inhibitor (MoFTI).

BACKGROUND: Protease inhibitors have been isolated from plants and present several biological activities, including immunomodulatory action. OBJECTIVE: This work aimed to evaluate a Moringa oleifera flower trypsin inhibitor (MoFTI) for acute toxicity in mice, hemolytic activity on mice erythrocytes and immunomodulatory effects on mice splenocytes. METHODS: The acute toxicity was evaluated using Swiss female mice that received a single dose of the vehicle control or MoFTI (300 mg/kg, i.p.). Behavioral alterations were observed 15-240 min after administration, and survival, weight gain, and water and food consumption were analyzed daily. Organ weights and hematological parameters were analyzed after 14 days. Hemolytic activity of MoFTI was tested using Swiss female mice erythrocytes. Splenocytes obtained from BALB/c mice were cultured in the absence or presence of MoFTI for the evaluation of cell viability and proliferation. Mitochondrial membrane potential (Δψm) and reactive oxygen species (ROS) levels were also determined. Furthermore, the culture supernatants were analyzed for the presence of cytokines and nitric oxide (NO). RESULTS: MoFTI did not cause death or any adverse effects on the mice except for abdominal contortions at 15-30 min after administration. MoFTI did not exhibit a significant hemolytic effect. In addition, MoFTI did not induce apoptosis or necrosis in splenocytes and had no effect on cell proliferation. Increases in cytosolic and mitochondrial ROS release, as well as Δψm reduction, were observed in MoFTI-treated cells. MoFTI was observed to induce TNF-α, IFN-γ, IL-6, IL-10, and NO release. CONCLUSION: These results contribute to the ongoing evaluation of the antitumor potential of MoFTI and its effects on other immunological targets.

A new Kunitz trypsin inhibitor from Erythrina poeppigiana exhibits antimicrobial and antibiofilm properties against bacteria.

Erythrina poeppigiana belongs to Fabaceae family (subfamily Papillionoideae) and is commonly found in tropical and subtropical regions in Brazil. Herein, we described the purification and characterization of a new Kunitz-type inhibitor, obtained from E. poeppigiana seeds (EpTI). EpTI is composed by three isoforms of identical amino-terminal sequences with a molecular weight ranging from 17 to 20 kDa. The physicochemical features showed by EpTI are common to Kunitz inhibitors, including the dissociation constant (13.1 nM), stability against thermal (37-100 °C) and pH (2-10) ranging, and the presence of disulfide bonds stabilizing its reactive site. Furthermore, we investigated the antimicrobial, anti-adhesion, and anti-biofilm properties of EpTI against Gram-positive and negative bacteria. The inhibitor showed antimicrobial activity with a minimum inhibitory concentration (MIC, 5-10 µM) and minimum bactericidal concentration (MBC) of 10 µM for Enterobacter aerogenes, Enterobacter cloacae, Klebsiella pneumoniae, Staphylococcus aureus, and Staphylococcus haemolyticus. The combination of EpTI with ciprofloxacin showed a marked synergistic effect, reducing the antibiotic concentration by 150%. The increase in crystal violet uptake for S. aureus and K. pneumoniae strains was approximately 30% and 50%, respectively, suggesting that the bacteria plasma membrane is targeted by EpTI. Treatment with EpTI at 1x and 10 x MIC significantly reduced the biofilm formation and prompted the disruption of a mature biofilm. At MIC/2, EpTI decreased the bacterial adhesion to polystyrene surface within 2 h. Finally, EpTI showed low toxicity in animal model Galleria mellonella. Given its antimicrobial and anti-biofilm properties, the EpTI sequence might be used to design novel drug prototypes.

Isolation and characterization of "Reprotoxin", a novel protein complex from Daboia russelii snake venom.

In snake venoms, non-covalent protein-protein interaction leads to protein complexes with synergistic and, at times, distinct pharmacological activities. Here we describe a new protein complex containing phospholipaseA(2) (PLA(2)), protease, and a trypsin inhibitor. It is isolated from the venom of Daboia russelii by gel permeation chromatography, on a Sephadex G-75 column. This 44.6 kDa complex exhibits only phospholipase A(2) activity. In the presence of 8M urea it is well resolved into protease (29.1 kDa), PLA(2) (13 kDa), and trypsin inhibitor (6.5 kDa) peaks. The complex showed an LD(50) of 5.06 mg/kg body weight in mice. It inhibited the frequency of spontaneous release of neurotransmitter in hippocampal neurons. It also caused peritoneal bleeding, and edema in the mouse foot pads. Interestingly, the complex caused degeneration of both the germ cells and the mouse Leydig cells of mouse testis. A significant reduction in both the diameter of the seminiferous tubules and height of the seminiferous epithelia were observed following intraperitoneal injection of the sub-lethal dose (3 mg/kg body weight). This effect of the toxin is supported by the increase in the activities of acid and alkaline phosphatases and the nitric oxide content in the testes, and a decrease in the ATPase activity. Because of its potent organ atrophic effects on the reproductive organs, the toxin is named "Reprotoxin". This is the first report demonstrating toxicity to the reproductive system by a toxin isolated from snake venom.

Adevonin, a novel synthetic antimicrobial peptide designed from the Adenanthera pavonina trypsin inhibitor (ApTI) sequence.

The biological activities and the structural arrangement of adevonin, a novel antimicrobial peptide, were investigated. The trypsin inhibitor ApTI, isolated from Adenanthera pavonina seeds, was used as a template for screening 18-amino acid peptides with predicted antimicrobial activity. Adevonin presented antimicrobial activity and minimum inhibitory concentrations (MIC) ranging from 1.86 to 7.35 µM against both Gram-positive and - negative bacterial strains. Moreover, adevonin exerted time-kill effects within 10 min and both susceptible and drug-resistant bacterial strains were affected by the peptide. In vitro and in vivo assays showed that, at MIC concentration, adevonin did not affect human fibroblasts (MRC-5) viability or Galleria mellonella survival, respectively. Hemolytic activity was observed only at high peptide concentrations. Additionally, nucleic acid efflux assays, gentian violet uptake and time-kill kinetics indicate that the antimicrobial activity of adevonin may be mediated by bacterial membrane damage. Furthermore, molecular dynamic simulation in the presence of SDS micelles and anionic membrane bilayers showed that adevonin acquired a stable α-helix secondary structure. Further studies are encouraged to better understand the mechanism of action of adevonin, as well as to investigate the anti-infective activity of this peptide.

Ingestion of Bt rice pollen does not reduce the survival or hypopharyngeal gland development of Apis mellifera adults.

Because of its ecological and economic importance, the honey bee Apis mellifera is commonly used to assess the environmental risk of insect-resistant, genetically modified plants. In the present study, feeding-exposure experiments were used to determine whether pollen from transgenic rice harms A. mellifera worker bees. In 1 experiment, the survival and mean acinus diameter of hypopharyngeal glands of adult bees were similar when bees were fed on pollen from Bt rice lines or from a non-Bt rice line, but bee survival was significantly reduced when they received pollen that was mixed with potassium arsenate as a positive control. In a second experiment, bee survival and hypopharyngeal gland development were not reduced when adult bees were fed on non-Bt pollen and a sucrose solution supplemented with Cry2A at 400 µg/g, Cry1C at 50 µg/g, or bovine serum albumin (BSA) at 400 µg/g, but bee survival and hypopharyngeal gland development were reduced when the diet was supplemented with soybean trypsin inhibitor as a positive control. In both experiments, the uptake of Cry proteins by adult bees was confirmed. Overall, the results indicate that the planting of Bt rice lines expressing Cry2A or Cry1C protein poses a negligible risk to A. mellifera worker bees. Environ Toxicol Chem 2017;36:1243-1248. © 2016 SETAC.

Assessment of Aprotinin Loaded Microemulsion Formulations for Parenteral Drug Delivery: Preparation, Characterization, in vitro Release and Cytotoxicity Studies.

The object of the current study was to prepare novel microemulsion formulations of aprotinin for parenteral delivery and to compare in vitro characteristics and release behaviour of different Technetium-99m ((99m)Tc)-Aprotinin loaded microemulsion formulations. In addition, cytotoxicity of microemulsion formulation was evaluated with cell culture studies on human immortalized pancreatic duct epithelial-like cells. For this aim, firstly, pseudo-ternary phase diagrams were plotted to detect the formulation region and optimal microemulsions were characterized for their thermodynamic stability, conductivity, particle size, zeta potential, viscosity, pH and in vitro release properties. For in vitro release studies aprotinin was labelled with (99m)Tc and labelling efficiency, radiochemical purity and stability of the radiolabeled complex were determined by several chromatography techniques. Radiolabeling efficiency of (99m)Tc-Aprotinin was found over than 90% without any significant changes up to 6 hours after labelling at room temperature. After that, in vitro release studies of (99m)Tc-Aprotinin loaded microemulsions were performed with two different methods; dissolution from diffusion cells and dialysis bags. Both methods showed that release rate of (99m)Tc- Aprotinin from microemulsion could be controlled by microemulsion formulations. Drug release from the optimized microemulsion formulations was found lower compared to drug solution at the end of six hours. According to stability studies, the optimized formulation was found to be stable over a period of 12 months. Also, human immortalized pancreatic duct epithelial-like cells were used to evaluate the cytotoxicity of optimum formulation. Developed microemulsion did not reveal cytotoxicity. In conclusion the present study indicated that the M1-APT microemulsion is appropriate for intravenous application of aprotinin.

Synthesis and inhibition of human acrosin and trypsin and acute toxicity of aryl 4-guanidinobenzoates.

The aryl 4-guanidinobenzoate, 4'-nitrophenyl 4-guanidinobenzoate (NPGB), is a potent inhibitor of sperm acrosin, an enzyme with an essential function in the fertilization process. NPGB prevents fertilization in a number of animal species and is a good lead compound for the development of contraceptive agents. In order to assess the efficacy of other aryl 4-guanidinobenzoates as acrosin inhibitors, 24 of these compounds were synthesized. Their inhibitory activity toward human acrosin was determined and compared with their activity toward human pancreatic trypsin in order to assess whether inhibitor sensitivity differed between these similar enzymes. Nine of the inhibitors were synthesized from phenols approved by the FDA for therapeutic use. The acute toxicity of these inhibitors in mice was determined and compared to that of nonoxynol-9, the most commonly used active ingredient in today's vaginal contraceptive preparations. All of the compounds proved to be potent inhibitors of human acrosin although 3 orders of magnitude difference were observed between the most and least effective inhibitors. Little specificity was present in regard to their inhibition of acrosin and trypsin. All the aryl 4-guanidinobenzoates synthesized from FDA-approved phenols were less toxic than nonoxynol-9, and it is concluded that these 4-guanidinobenzoates are of interest for further development and testing as nonhormonal contraceptive agents.

Pancreatic polyamine concentrations and cholecystokinin plasma levels in rats after feeding raw or heat-inactivated soybean flour.

We investigated the trophic effect on the pancreas of male Wistar rats fed up to 20 days with either raw soybean flour (RSF) containing an active trypsin inhibitor or heat-inactivated soybean flour (HSF). The concentrations of the polyamines putrescine, spermidine, and spermine in the pancreas as well as cholecystokinin (CCK) concentrations in arterial and portal vein plasma were measured. Plasma CCK concentrations were measured by a sensitive radioimmunoassay specific for the sulfated region of CCK, whereas polyamine concentrations are determined by reversed phase high-performance liquid chromatography. The levels of CCK in both arterial and portal vein plasma were significantly higher in RSF- compared with HSF-fed rats, the concentration in the portal vein being twice as high compared with the aorta. A significant increase in pancreatic weight and protein content was positively correlated to an increase in putrescine and spermidine in the pancreas of RSF-fed rats compared with HSF-fed controls, whereas the spermine content did not differ between the two groups. The pancreatic DNA content in RSF-fed rats was significantly above control values of day 20 only. These data support the hypothesis that the trophic effect of soybean trypsin inhibitor on the pancreas is mediated by CCK and that polyamines might play an important role in CCK-induced pancreatic growth.

Random or selective cell death during pancreatic involution following withdrawal of raw soya flour feeding in the rat.

Feeding a diet of raw soya flour, which contains a trypsin inhibitor, results in pancreatic hypertrophy and hyperplasia, and when this diet is withdrawn rapid involution ensues. This study examines whether cells produced during the hyperplastic response to raw soya four (RSF) are selectively destroyed during involution following the withdrawal of this diet. Six week old male Wistar rats were fed RSF. At 7, 9 and 12 d after commencing the diet, during the period of maximum cell proliferation, rats were injected with 0.5 muCi/g body weight of tritiated thymidine. The rats were continued on this diet for a further 16d. By 1 mth pancreatic DNA, RNA, protein, weight and the specific activity of pancreatic DNA were all significantly greater in rats fed RSF, compared to control rats fed a standard diet. When rats fed RSF were changed to a diet free of trypsin inhibitor for 7 d, pancreatic DNA, RNA, protein and weight returned to control values, however the specific activity of DNA remained unchanged from the RSF value. This report suggests that cell death involves cells produced before and during the hyperplastic response to RSF, since there is no change in the specific activity of the organ after involution.

Early indicators of exocrine pancreas carcinogenesis produced by non-genotoxic agents.

In the past 40 years the incidence of pancreatic cancer in many Western countries had increased. Since no single factor responsible for the development of pancreatic cancer has been identified, it is believed that non-genotoxic factors may play an important role in the pathogenesis of this highly fatal form of cancer. Focal abnormalities of acinar cells, referred to as atypical acinar cell foci or nodules, occur spontaneously in rats and some other species. Their incidence increases with age from zero at birth to about 75% in 2-year-old rats. These spontaneous lesions have a phenotype that cannot be distinguished from the putative, atypical preneoplastic, acinar cell foci induced in rat pancreas by the carcinogen azaserine. Unsaturated fat (corn oil) has been found to increase the incidence of atypical acinar cell nodules and adenomas in the pancreas of non-carcinogen-treated rats without influencing the weight of the pancreas. Furthermore, unsaturated fat has a specific promoting effect on the growth potential of atypical acinar cell foci and nodules induced in rat pancreas by azaserine, resulting in an increase in the number and size of these lesions. Rats fed raw soya flour or trypsin inhibitors develop an enlarged pancreas as a result of hypertrophy and hyperplasia. They also develop acidophilic atypical acinar cell foci and nodules, adenomas and adenocarcinomas after being fed full-fat raw soya flour for 2 years. It may be concluded from the observations in rat pancreas that non-genotoxic compounds or conditions that enhance pancreatic growth may be classified as non-genotoxic pancreatic tumour promoters. The observations with corn oil, however, indicate that there may be non-genotoxic compounds that specifically enhance growth of spontaneous initiated atypical acinar cell foci without causing hyperplasia of the pancreas. The possible mechanisms whereby unsaturated fat and trypsin inhibitors exert their effects on exocrine pancreatic carcinogenesis are discussed.

Effects of dietary soya bean trypsin inhibitor concentrate on initiation and growth of putative preneoplastic lesions in the pancreas of the rat.

Two studies evaluated the effects of soya bean trypsin inhibitor concentrate (STIC) on early stages of pancreatic carcinogenesis in Wistar rats. In experiment 1, the effects of a 3-month administration of diets containing 3.7% STIC were compared with the effects of administration of diets containing 20% corn oil, in rats pretreated with a single azaserine injection sufficient to initiate putative preneoplastic atypical acinar cell foci. Experiment 2 investigated the capacity of STIC to initiate pancreatic carcinogenesis. Diets containing 3.7% STIC were fed for 4 wk, then diets containing either 5 or 20% corn oil were fed for 3 months. Pancreases were quantitatively evaluated for foci. All groups of azaserine-initiated rats had large numbers of atypical acinar cell foci per cm3 of pancreas. Of these, the group fed 3.7% STIC had pancreatic foci that occupied a significantly greater (P less than 0.01) percentage volume of pancreas than did groups fed 20% corn oil or control diets, which contained 5% corn oil and no added trypsin inhibitor. Very few or no foci were observed in all other groups of either experiment 1 or 2. STIC had a much greater effect on the growth of azaserine-induced lesions than did corn oil. STIC alone did not appear to initiate pancreatic lesions.

Residue trypsin inhibitor: data needs for risk assessment.

Trypsin inhibitor (TI) occurs naturally in many foods from plants, notably soybean protein products. Heat treatment inactivates TI and improves nutritional quality, but residual TI activity of 5 to 20% remains after typical commercial treatments. Chronic feeding of TI or products that contain TI can inhibit trypsin and chymotrypsin, stimulate their secretion, cause hypertrophy and hyperplasia of the pancreas, and lead to adenomas and carcinomas of the exocrine pancreas. In the rat, TI promotes pancreatic carcinogenesis initiated by azaserine. Data needed for possible risk assessment on TI would include 2-year bioassays from animals treated with TI and fed diets carefully controlled for type and amount of fat (which also promotes pancreatic carcinogenesis). The effects of TI on protein nutrition would have to be considered when identifying the maximum tolerated dose. Major reductions in human dietary TI exposure may not be feasible because of the multiple sources of TI, the substantial promotion by other factors such as fat, and the adverse effects of excessive heat on food products. For risk assessment of TI in a particular food, other promotors and the feasibility of decreasing TI intake must be considered.

Accentuated response to soybean inhibitors by meal-feeding in various species.

Diets containing raw soybean products (RSD) fed ad libitum caused a reduction in food consumption and growth, pancreatic enlargement, hypersecretion of digestive enzymes, and enlargement of intestinal segments and their contents in rats, chicks and geese. These effects were found to be related to the concentration of trypsin inhibitor (TI) in the diet. Geese were more sensitive than rats and chicks. Calves fed RSD did not respond in pancreatic hypertrophy and hypersecretion of digestive enzymes, but growth was depressed. Meal-feeding also caused enlargement of the pancreas, digestive tract segments and their contents. The effects of feeding RSD and of meal feeding were found to be additive. In ad libitum feeding the animal can regulate food consumption and moderate the effects of antinutritional factors in the diet. Meal or tube-feeding interfered with this defense mechanism and the negative effects of RSD were accentuated and were lethal in non adapted rats and geese. In long-term studies the incidence of pancreatic nodules was correlated to the level of TI in the diet. Feeding RSD potentiated the carcinogenic effect of azaserine and meal feeding enhanced the incidence and size of the pancreatic nodules in rats fed RSD.

Antinutritional and biochemical properties of winged bean trypsin inhibitors.

The trypsin inhibitors (TI) of winged bean (Psophocarpus tetragonolobus) isolated by affinity chromatography consisted of 8 protein bands by disc polyacrylamide electrophoresis. All the bands exhibited trypsin inhibitor activity (TIA) with two of the major bands also exhibiting chymotrypsin inhibitor activity (CIA). Electrofocusing separated the TI into 5 protein bands. Two bands with dual TIA/CIA activities had acidic pI while 3 bands with TIA only had alkaline pI. The TI belonged to two molecular weight groups of 20,900 and 16,600, as determined by NaDodSo4 polyacrylamide electrophoresis. Sufficient quantities of TI were isolated by affinity chromatography for rat feeding. Raw winged bean was toxic to rats, causing death after 12 days of feeding. Autoclaved winged bean was not toxic but caused growth inhibition. When fed with casein, the isolated inhibitor caused slight growth inhibition, pancreatic and spleen hypertrophy. It was concluded that TI in winged bean was not primarily responsible for the toxicity of raw winged bean.

Production and nutritive value of soybeans.

Soybean world production has been increasing at a rate of 5.2% per year (average yield is around 1,400 kg/ha). This production has been solely used for oil extraction and the protein meal obtained for animal rations, but lately it is being used for human consumption. Brazil, the third largest producer, has had a yearly rate of production increase of 32% in the last years. Average yields in Brazil are still low (around 1,500 kg/ha), but in experimental results, yields over 3,000 kg/ha have been obtained. Some problems needstill to be solved, such as obtention of adapted varieties, soil fertility, adequate agronomic practices, damage by insects and diseases. Protein and oil contents are highly negative correlated, they are genetically controlled and can also be influenced by environmental conditions and agronomic practices. To breed for high protein (above 48%) enhances a decrease in oil and yield, but new varieties containing 43% protein and with a good yielding capacity have been developed lately. Methionine content varies from 1.0 to 1.6% g/16g N; there is a correlation of 0.56 to 0.58 between methionine in the protein and protein in the seed. Particular attention has been given to toxic factors such as trypsin inhibitors, whose action is related to the availability or utilization of methionine; this effect, however, can be eliminated by heat.