A comprehensive study from the micro- to the nanometric scale: Evaluation of chilling injury in tomato fruit (Solanum lycopersicum).

Tomato fruit is susceptible to chilling injury (CI) during its postharvest handling at low temperature. The symptoms caused by this physiological disorder have been commonly evaluated by visual inspection at a macro-observation scale on fruit surface; however, the structure at deeper scales is also affected by CI. This work aimed to propose a descriptive model of the CI development in tomato tissue under the micro-scale, micro-nano-scale and nano-scale approaches using fractal analysis. For that, quality and fractal parameters were determined. In this sense, light microscopy, Environmental Scanning Electron Microscopy (ESEM) and Atomic Force Microscopy (AFM) were applied to analyse micro-, micro-nano- and nano-scales, respectively. Results showed that the morphology of tomato tissue at the micro-scale level was properly described by the multifractal behaviour. Also, generalised fractal dimension (Dq=0) and texture fractal dimension (FD) of CI-damaged pericarp and cuticle were higher (1.659, 1.601 and 1.746, respectively) in comparison to non-chilled samples (1.606, 1.578 and 1.644, respectively); however, FD was unsuitable to detect morphological changes at the nano-scale. On the other hand, lacunarity represented an appropriate fractal parameter to detect CI symptoms at the nano-scale due to differences observed between damaged and regular ripe tissue (0.044 and 0.025, respectively). The proposed multi-scale approach could improve the understanding of CI as a complex disorder to the development of novel techniques to avoid this postharvest issue at different observation scales.

Pharmacological evaluation of the immunomodulatory FL-6 in induced chronic hepatitis in Wistar rats.

The aim of this study was to evaluate the pharmacological effect of FL-6, a new immunomodulatory drug, in chronic hepatitis immunologically induced in rats via porcine-serum (PS) administration. Thirty-two male Wistar rats (150 g) were divided into 4 experimental groups: (1) Control (PBS 0.5 ml 3-times per week for 8-week); (2) FL-6 (50 ng/kg 3-times per week for 4-week); (3) Hepatitis (PS 373 mg/kg twice per week for 8-week); and (4) Hepatitis + FL-6 (doses as above). Rats were sacrificed at the end of treatment. ALT, AST, ALP and gamma-GT activities, as well as IL-6 and IL-10 levels, were evaluated in serum samples. Glutathione and malondialdehyde were also analyzed. A morphological analysis of liver tissue was carried out. The hepatitis group showed an increase in ALT (1.44-fold), AST (1.28-fold), ALP (1.83-fold), gamma-GT (3.91-fold), IL-6 (2.6-fold) and IL-10 (7.1-fold) levels when compared with controls (p < 0.05). Histopathological analysis revealed an inflammatory response characterized by inflammatory infiltrates and liver damage, which was accompanied by a reduction of 74.8% in glutathione levels (p < 0.05). However, animals with hepatitis treated with FL-6 had a reduction of ALT activity (17.74%), as well as a reduction in IL-6 (24.21%) and IL-10 (30.91%) levels (p < 0.05). These animals showed a reduction in inflammatory response characterized by a decrease in inflammatory infiltrate at the hepatic parenchyma and portal structures; livers showed less damage and a reduction of necrotic and apoptotic hepatocytes. In conclusion, the treatment with FL-6 improved liver function and reduced the inflammatory marker in rats with chronic hepatitis induced by PS-administration.