As a staple food, bread digestibility deserves a marked nutritional interest. Combining wide-spectrum characterization of breads, in vitro nutritional indices, and in vivo postprandial markers of gastrointestinal function, we aimed at comparing the digestibility of sourdough and baker’s yeast breads. Microbiological and biochemical data showed the representativeness of the baker´s yeast bread (BYB) and the two sourdough breads (SB and t-SB, mainly differing for the time of fermentation) manufactured at semi-industrial level. All in vitro nutritional indices had the highest scores for sourdough breads. Thirty-six healthy volunteers underwent an in vivo challenge in response to bread ingestion, while monitoring gallbladder, stomach, and oro-cecal motility. SB, made with moderate sourdough acidification, stimulated more appetite and induced lower satiety. t-SB, having the most intense acidic taste, induced the highest fullness perception in the shortest time. Gallbladder response did not differ among breads, while gastric emptying was faster with sourdough breads. Oro-cecal transit was prolonged for BYB and faster for sourdough breads, especially when made with traditional and long-time fermentation (t-SB), whose transit lasted ca. 20 min less than BYB. Differences in carbohydrate digestibility and absorption determined different post-prandial glycaemia responses. Sourdough breads had the lowest values. After ingesting sourdough breads, which had a concentration of total free amino acids markedly higher than that of BYB, the levels in blood plasma were maintained at constantly high levels for extended time.

Azathioprine is an immunosuppressant drug widely used. Our purpose was to 1) determine whether its associated hepatotoxicity could be attributable to the induction of a necrotic or apoptotic effect in hepatocytes, and 2) elucidate the mechanism involved. To evaluate cellular responses to azathioprine, we used primary culture of isolated rat hepatocytes. Cell metabolic activity, reduced glutathione, cell proliferation, and lactate dehydrogenase release were assessed. Mitochondria were isolated from rat livers, and swelling and oxygen consumption were measured. Mitogen-activated protein kinase pathways and proteins implicated in cell death were analyzed. Azathioprine decreased the viability of hepatocytes and induced the following events: intracellular reduced glutathione (GSH) depletion, metabolic activity reduction, and lactate dehydrogenase release. However, the cell death was not accompanied by DNA laddering, procaspase-3 cleavage, and cytochrome c release. The negative effects of azathioprine on the viability of hepatocytes were prevented by cotreatment with N-acetyl-l-cysteine. In contrast, 6-mercaptopurine showed no effects on GSH content and metabolic activity. Azathioprine effect on hepatocytes was associated with swelling and increased oxygen consumption of intact isolated rat liver mitochondria. Both effects were cyclosporine A-sensitive, suggesting an involvement of the mitochondrial permeability transition pore in the response to azathioprine. In addition, the drug's effects on hepatocyte viability were partially abrogated by c-Jun N-terminal kinase and p38 kinase inhibitors. In conclusion, our findings suggest that azathioprine effects correlate to mitochondrial dysfunction and activation of stress-activated protein kinase pathways leading to necrotic cell death. These negative effects of the drug could be prevented by coincubation with N-acetyl-l-cysteine.

We performed a comprehensive study encompassing chemical characterization and sensory evaluation of two types of dark chocolate, i.e., artisanal (Choco-A) and industrial (Choco-I), as well as an evaluation of onset of gastrointestinal symptoms and gastrointestinal motility in healthy subjects fed with dark chocolate. Proteomic, lipid and metabolite analysis were performed by LC-MS/MS analysis and the total phenol content and antioxidant activity were estimated in both types of chocolate. Fifty healthy volunteers joined the study of the sensory characteristics of both types of chocolate; another 16 subjects underwent the study of gallbladder and gastric emptying by functional ultrasonography and orocecal transit time by lactulose H₂-breath test after ingestion of dark chocolate. Identification of polyphenols, amino acids and fatty acids was carried out in both types of chocolate analysed, and results confirmed their richness in polyphenols, amino acid derivatives and fatty acids (FAs) either saturated (stearic, myristic, palmitic, ecosanoic) or unsaturated (oleic and linolenic). For agreeability, Choco-A scored higher than Choco-I for smell, texture, and taste and they did not show significant differences in the gastrointestinal motility. In conclusion as for gastrointestinal motility studies, we report that the ingestion of a small amount of chocolate induced a mild gallbladder, gastric contraction and a fast transit time compared to the test meal in healthy subjects.

Structural and functional characteristics of subunits of bovine heart cytochrome‐c reductase have been investigated by controlled digestion of soluble and membrane‐reconstituted purified bc₁ complex and direct amino acid sequencing of native and digested protein subunits.The results obtained show that the N‐terminal segments of core protein II and the 14‐kDa protein extend at the periphery of the complex, protruding into the inner matrix space. The Fe‐S protein, located at the outer C‐periphery of the complex, is shown to be anchored to other subunits of the complex by the amphipathic N‐terminal region. Proteolytic cleavage of 7–11 residues from the N‐terminal segment of the 14‐kDa protein is apparently associated with decoupling of redox‐linked proton pumping. Partial digestion of core protein II, the 6.4‐kDa protein, and the C‐terminal region of the 9.2‐kDa protein, is without effect on the redox and proton‐motive activity of the complex.

Background: Almonds are healthy nutraceuticals, which vary across different cultivars. We compared the composition, agreeability and gastrointestinal effects of two almond cultivars from different areas.Methods: Californian Carmel (CAcv) and local Apulian Filippo Cea (FCcv) cultivars were compared for the chemical composition and sensory evaluation according to visual analogue and semiquantitative scales in 60 volunteers. Gallbladder/gastric motility (ultrasonography) and orocecal transit time (H2-breath test) were studied in another 24 subjects by comparing the effects of a standard liquid test meal with isovolumetric almond test meals (24 g of CAcv or FCcv almonds).Results: Proteins prevailed in CAcv, while FCcv contained more lipids and 10-times more total phenol content than CAcv. For agreeability, CAcv scored higher than FCcv for smell, texture and appearance, although different perceptions existed in lean (scores for smell, taste, texture, appearance higher for CAcv than FCcv), obese (CAcv better than FCcv only for appearance) and elderly subjects (CAcv better than FCcv only for texture). Gallbladder emptying was stronger with FCcv than CAcv. Antral dilatation after ingestion of both cultivars was greater than the dilatation observed after the test meal. Gastric emptying, however, was similar after FCcv, CAcv and the test meal. The orocecal transit time in response to both cultivars was shorter than after the test meal.Conclusions: Differences in composition and effects of FCcv and CAcv cultivars support their potential use as valuable nutraceutical tools, to be confirmed in further clinical studies.