In vitro and in vivo studies of Cucurbita pepo L. flowers: chemical profile and bioactivity.

Edible flowers consumption has increased in recent years due to their rich content of healthy phytochemicals. The aim of this study was to analyse the chemical profile of Cucurbita pepo L. flowers, and to explore their antioxidant and hypoglycaemic properties. Moreover, in order to assess in vivo effects, biochemical analysis, Reactive Oxygen Metabolites (d-ROMs) and Biological Antioxidant Potential (BAP) tests were performed on mice serum. High Performance Liquid Chromatography-Diode Array Detection (HPLC-DAD) analyses revealed the presence of (+)-catechin, (-)-epicatechin, rutin, and syringic acid as main constituents. 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and Ferric Reducing Antioxidant Power (FRAP) tests showed interesting results. The extract exhibited the strongest inhibitory effect on α-glucosidase (IC50 of 144.77 µg/mL). In vivo results confirmed the hypoglycaemic effects, also affecting lipid metabolism but did not revealed benefits on ROS production. These results may add some information supporting the use of C. pepo flowers as functional foods and/or nutraceuticals.

Improved in vitro and in vivo collagen biosynthesis by asiaticoside-loaded ultradeformable vesicles.

The potentiality of ultradeformable vesicles as a possible topical delivery system for asiaticoside, a natural compound obtained from Centella asiatica was evaluated, because this compound exhibits collagen biosynthesis promoting activity. Ultradeformable vesicles were prepared by the extrusion technique; these vesicles were composed of Phospholipon 100 and different molar fractions of sodium cholate as the edge activator. The physicochemical properties of the ultradeformable vesicles were investigated through differential scanning calorimetry and light scattering techniques. The potential cyctotoxicity and biological activity of asiaticoside-loaded ultradeformable vesicles were evaluated on primary human dermal fibroblast cells by determining the extracellular lactic dehydrogenase activity, the cellular viability and the biosynthetic production of collagen. In vitro permeation experiments through human stratum corneum and epidermis membranes were also carried out. Ultradeformable vesicles having sodium cholate molar fraction of 0.2 proved to be the most suitable topical carriers for asiaticoside. A sodium cholate content of >0.2 was observed to be cytotoxic probably due to its co-existence with other lipid aggregates, an example being mixed micelles. Asiaticoside-loaded ultradeformable vesicles with a sodium cholate molar fraction of 0.2 elicited the greatest degree of collagen biosynthesis in human fibroblasts. Ultradeformable vesicles provided the greatest in vitro skin permeation of asiaticoside showing a 10-fold increase with respect to the free drug solution and favoured an increase in in vivo collagen biosynthesis. Ultradeformable vesicles are therefore suitable carriers for the pharmaceutical and cosmetic application of the natural agent asiaticoside.