Fabiana Maria Coimbra de Carvalho

Supplementation with a new trypsin inhibitor from peanut is associated with reduced fasting glucose, weight control, and increased plasma CCK secretion in an animal model

Abstract Ingestion of peanuts may have a beneficial effect on weight control, possibly due to the satietogenic action of trypsin inhibitors. The aim of this study was to isolate a new trypsin inhibitor in a typical Brazilian peanut sweet (paçoca) and evaluate its effect in biochemical parameters, weight gain and food intake in male Wistar rats. The trypsin inhibitor in peanut paçoca (AHTI) was isolated. Experimental diets were prepared with AIN-93G supplemented with AHTI. Animals had their weight and food intake monitored. Animals were anesthetized, euthanized, and their bloods collected by cardiac puncture for dosage of cholecystokinin (CCK) and other biochemical parameters. Supplementation with AHTI significantly decreased fasting glucose, body weight gain, and food intake. These effects may be attributed to increased satiety, once supplemented animals showed no evidence of impaired nutritional status and also because AHTI increased CCK production. Thus, our results indicate that AHTI, besides reducing fasting glucose, can reduce weight gain via food intake reduction.

A Trypsin Inhibitor from Tamarind Reduces Food Intake and Improves Inflammatory Status in Rats with Metabolic Syndrome Regardless of Weight Loss

Trypsin inhibitors are studied in a variety of models for their anti-obesity and anti-inflammatory bioactive properties. Our group has previously demonstrated the satietogenic effect of tamarind seed trypsin inhibitors (TTI) in eutrophic mouse models and anti-inflammatory effects of other trypsin inhibitors. In this study, we evaluated TTI effect upon satiety, biochemical and inflammatory parameters in an experimental model of metabolic syndrome (MetS). Three groups of n = 5 male Wistar rats with obesity-based MetS received for 10 days one of the following: (1) Cafeteria diet; (2) Cafeteria diet + TTI (25 mg/kg); and (3) Standard diet. TTI reduced food intake in animals with MetS. Nevertheless, weight gain was not different between studied groups. Dyslipidemia parameters were not different with the use of TTI, only the group receiving standard diet showed lower very low density lipoprotein (VLDL) and triglycerides (TG) (Kruskal–Wallis, p < 0.05). Interleukin-6 (IL-6) production did not differ between groups. Interestingly, tumor necrosis factor-alpha (TNF-α) was lower in animals receiving TTI. Our results corroborate the satietogenic effect of TTI in a MetS model. Furthermore, we showed that TTI added to a cafeteria diet may decrease inflammation regardless of weight loss. This puts TTI as a candidate for studies to test its effectiveness as an adjuvant in MetS treatment.

Biochemical characterisation of a Kunitz-type inhibitor from Tamarindus indica L. seeds and its efficacy in reducing plasma leptin in an experimental model of obesity

Abstract A trypsin inhibitor isolated from tamarind seed (TTI) has satietogenic effects in animals, increasing the cholecystokinin (CCK) in eutrophy and reducing leptin in obesity. We purified TTI (pTTI), characterised, and observed its effect upon CCK and leptin in obese Wistar rats. By HPLC, and after amplification of resolution, two protein fractions were observed: Fr1 and Fr2, with average mass of [M + 14H]+ = 19,594,690 Da and [M + 13H]+ = 19,578,266 Da, respectively. The protein fractions showed 54 and 53 amino acid residues with the same sequence. pTTI presented resistance to temperature and pH variations; IC50 was 2.7 × 10−10 mol.L−1 and Ki was 2.9 × 10−11 mol.L−1. The 2-DE revealed spots with isoelectric points between pH 5 and 6, and one near pH 8. pTTI action on leptin decrease was confirmed. We conclude that pTTI is a Kunitz trypsin inhibitor with possible biotechnological health-related application.

Atividade antitríptica de proteínas em polpas e sementes de frutas tropicais

A healthy and diversified eating is essential for the maintenance of physical and mental health, and despite the current trend that appreciates the convenience of eating, it is noted that the population is increasingly consuming fruit, both in natura and / or juices. However, the use of certain fresh fruits is accompanied by the consumption of the seeds, peels or other parts may contain antinutritional factors, molecules and / or compounds that may adversely affect the bioavailability and / or digestibility of nutrients, such as inhibitors of trypsin. Such inhibitors may impair the utilization of proteins in food, but recent studies have been published also demonstrating the beneficial effects of the same. This study aimed to evaluate the trypsin inhibitors in aqueous extracts of fruits: guava (Psidium guajava L) varieties Kumagai (white) and Paluma (red), yellow passion fruit (Passiflora edulis f.) and watermelon (Citrullus vulgaris Schrad). Tests were done in order to detect the presence of antitryptic activity and the dosage of soluble proteins. Trypsin inhibitory activity was detected in all extracts tested, as well as soluble proteins. Thus, inhibition can be explained by the presence of an inhibitor protein, because it was possible, in seed extracts, in SDS-PAGE, to visualize a wide range of protein bands. It is noteworthy that in the study, the protein bands that coincide with the molecular masses of the trypsin inhibitors did not appear in a majority, showing that seed extracts are likely to have protein inhibitor, however sparingly, justifying the low antitryptic activity (1, 36 to 15.15 IU / mg of dry weight), also shown by the extracts of the pulp. Therefore, having the recommended consumption of fruits including guava, passion fruit and watermelon in sight, possibly this inhibitory activity is more related to benefits than to hazards, regarding ones health. However, it is important to emphasize a careful consumption of large quantities of seeds present in these fruits.