Taioba (Xanthosoma sagittifolium) leaves: nutrient composition and physiological effects on healthy rats.

Several studies have shown that fruits and vegetables contribute to protect against degenerative pathologies such as cardiovascular diseases, diabetes, and cancer, mainly due to the presence of dietary fiber (DF) and polyphenols. Taioba (Xanthosoma sagittifolium) is an edible aroid widely grown in many parts of Africa, America, and Asia. The tubers portions of taioba are widely consumed; however, the leafy portions are generally discarded, despite their high nutritive value. In this study, we have partly characterized the DF of lyophiized taioba leaf (LTL), and assessed the possible protective effects on biochemical parameters and on bile acid (BA) production in colon and cecum, when fed to healthy rats for 4 wk. Forty-five Wistar rats were assigned to either of 5 groups: group 1 received AIN 93G diet (CG: Control); group 2 received AIN 93G containing 2.5% of cellulose + 2.5% inulin (CEIN_5%); group 3 received AIN 93G containing 2.5% of cellulose + 2.5% taioba fiber (CETA_5%); group 4 received AIN 93G containing 5% cellulose + 2.5% taioba fiber (CETA_7.5%); group 5 received AIN 93G containing 5% cellulose + 2.5% of inulin (CEIN_7.5%). LTL showed high contents of total fiber, predominantly comprising insoluble DF with glucose as the major monomer. Rats receiving LTL had increased fecal mass and fat excretion, and improved BA profiles by diminishing the proportion of secondary acids, thus suggesting that consumption of taioba leaf may have the property of lowering the risk of colon cancer.

A food supplement of hydrolyzed collagen improves compositional and biodynamic characteristics of vertebrae in ovariectomized rats.

Collagen hydrolysates (CHs) are mixtures of peptides obtained by partial hydrolysis of gelatins that are receiving scientific attention as potential oral supplements for the recovery of osteoarticular tissues. The effect of supplementing the diets with a CH was assessed in 48 ovariectomized rats by analyzing the compositional and biomechanical characteristics of the bone. Six groups of rats (three ovariectomized, one sham-operated, and two intact) were fed a standard diet, supplemented with either CH or gelatin (Control), at two levels: a dose equivalent to five times the amount suggested for humans (10 g/day) or another 10 times greater. After 8 weeks, the femora and vertebrae were excised, the blood was collected, and serum alkaline phosphatase and osteocalcin were determined. Bone weight, total protein, and biomechanical strength were also determined. The vertebrae of the ovariectomized group that received the higher dosage of CH withstood a load four times greater and exhibited higher levels of protein and osteocalcin content than those receiving either gelatin or no supplement. CH supplementation at the higher level in the ovariectomized rat had an unequivocal contribution in the conservation or preservation of vertebral mass, protein content, and mechanical strength not seen when gelatin was used as a supplement. Similar treatment of the intact rat with the CH, however, appeared to have the opposite effect.