Addition of Spirulina to Craft Beer: Evaluation of the Effects on Volatile Flavor Profile and Cytoprotective Properties

SPME-GC-MS and PTR-ToF-MS techniques were applied to describe the content of volatile flavor compounds in a craft beer before and after adding spirulina. The obtained results showed that the volatile profile of the two beer samples differed. Furthermore, to chemically characterize biomass spirulina, a derivatization reaction followed by GC-MS analysis was performed, highlighting a high content of molecules belonging to different chemical classes, such as sugars, fatty acids and carboxylic acids. A spectrophotometric analysis of total polyphenols and tannins, investigation into the scavenging activity towards DPPH and ABTS radicals and confocal microscopy of brewer's yeast cells were carried out. Moreover, the cytoprotective and antioxidant properties towards the oxidative damage induced by tert-butyl hydroperoxide (tBOOH) in human H69 cholangiocytes were investigated. Finally, the modulation of Nrf2 signaling under oxidative stress conditions was also evaluated. Both samples of beer were shown to contain similar levels of total polyphenols and tannins, with slightly increased levels in that containing spirulina 0.25% w/v. Moreover, the beers were found to be endowed with radical scavenging properties towards both DPPH and ABTS radicals, albeit with a weak contribution of spirulina; however, a higher riboflavin content was detected in spirulina-treated yeast cells. Conversely, the addition of spirulina (0.25% w/v) appeared to improve the cytoprotective properties of beer towards tBOOH-induced oxidative damage in H69 cells and reduce intracellular oxidative stress. Accordingly, the cytosolic Nrf2 expression was found to be increased.

Therapeutic and nutraceutical potential of rosmarinic acid-Cytoprotective properties and pharmacokinetic profile

Rosmarinic acid (RA) is a natural polyphenolic antioxidant derived from many common herbal plants. This compound displays several important biological properties, including anti-inflammatory, antiviral, antibacterial, antidepressant, anticarcionogenic, and chemopreventive properties. The importance of its activities and its possible application in processed foods as a natural antioxidant has reached a new interest levels in recent years. The health effects of this polyphenol depend greatly on both its intakes and bioavailability. This review focuses on the importance of RA as a dietary supplement, and summarizes its pharmacokinetics and metabolism, including the factors that limit its oral bioavailability which leads to a lower therapeutic action. Further experimental investigations are needed to optimize and enhance the oral bioavailability of this natural compound which consequently will help increasing therapeutic efficacy of RA in vivo.

Sitagliptin prevents aggravation of endocrine and exocrine pancreatic damage in the Zucker Diabetic Fatty rat - focus on amelioration of metabolic profile and tissue cytoprotective properties

BACKGROUND

The purpose of this study was to investigate some of the possible mechanisms underlying the protective effects of a dipeptidyl peptidase IV (DPP-IV) inhibitor, sitagliptin, on pancreatic tissue in an animal model of type 2 diabetes mellitus (T2DM), the Zucker Diabetic Fatty (ZDF) rat, focusing on glycaemic, insulinic and lipidic profiles, as well as, on apoptosis, inflammation, angiogenesis and proliferation mediators.

METHODS

Male obese diabetic ZDF (fa/fa) rats, aged 20 weeks, were treated with sitagliptin (10 mg/kg bw/day) during 6 weeks and compared to untreated diabetic and lean control littermates. Metabolic data was evaluated at the beginning and at the end of the treatment, including glycaemia, HbA1c, insulinaemia, HOMA-beta and TGs. Endocrine and exocrine pancreas lesions were assessed semiquantitatively by histopathological methods. Pancreas gene (mRNA) and protein expression of mediators of apoptotic machinery, inflammation and angiogenesis/proliferation (Bax, Bcl2, IL-1β, VEGF, PCNA and TRIB3) were analyzed by RT-qPCR and/or by immunohistochemistry.

RESULTS

Sitagliptin treatment for 6 weeks (between 20 and 26 week-old) was able to significantly (p < 0.001) ameliorate all the metabolic parameters, by preventing the increase in blood glucose and in serum TGs contents (16.54% and 37.63%, respectively, vs untreated), as well as, by preventing the decrease in serum insulin levels and in the functional beta cells capacity accessed via HOMA-beta index (156.28% and 191.74%, respectively, vs untreated). Sitagliptin-treated diabetic rats presented a reduced pancreas Bax/Bcl2 ratio, suggestive of an antiapoptotic effect; in addition, sitagliptin was able to completely reduce (p < 0.001) the pancreas overexpression of IL-1β and TRIB3 found in the untreated diabetic animals; and promoted a significant (p < 0.001) overexpression of VEGF and PCNA.

CONCLUSION

In this animal model of obese T2DM (the ZDF rat), sitagliptin prevented β-cell dysfunction and evolution of pancreatic damage. The protective effects afforded by this DPP-IV inhibitor may derive from improvement of the metabolic profile (viewed by the amelioration of glucose and TGs levels and of insulin resistance) and from cytoprotective properties, such as antiapoptotic, anti-inflammatory, pro-angiogenic and pro-proliferative.