Antioxidant activity of strawberry (Fragaria × ananassa Duch.) leaves

Green Synthesis of Iron Nanoparticles Using an Aqueous Extract of Strawberry (Fragaria × ananassa Duchesne) Leaf Waste

In this study, we analysed the potential use of dried strawberry leaves and calyces for the production of nanoparticles using inorganic iron compounds. We used the following iron precursors FeCl3 × 6H2O, FeCl2 × 4H2O, Fe(NO3)3 × 9H2O, Fe2(SO4)3 × H2O, FeSO4 × 7H2O, FeCl3 anhydrous. It was discovered that the content of polyphenols and flavonoids in dried strawberries and their antioxidant activity in DPPH and FRAP were 346.81 µM TE/1 g and 331.71 µM TE/1 g, respectively, and were similar to these of green tea extracts. Microimages made using TEM techniques allowed for the isolation of a few nanoparticles with dimensions ranging from tens of nanometres to several micrometres. The value of the electrokinetic potential in all samples was negative and ranged from -21,300 mV to -11,183 mV. XRF analyses confirmed the presence of iron ranging from 0.13% to 0.92% in the samples with a concentration of 0.01 mol/dm3. FT-IR spectra analyses showed bands characteristic of nanoparticles. In calorimetric measurements, no increase in temperature was observed in any of the tests during exposure to the electromagnetic field. In summary, using the extract from dried strawberry leaves and calyxes as a reagent, we can obtain iron nanoparticles with sizes dependent on the concentration of the precursor.

Strawberry Fragaria x ananassa cv. Festival: A Polyphenol-Based Phytochemical Characterization in Fruit and Leaf Extracts

Berry fruits are an important dietary source of health-promoting antioxidant polyphenols. Interestingly, berry leaves of diverse species, including strawberries, have shown higher bioactive phytochemical content in the leaves than in the fruit. Moreover, the vegetative part of the plants is usually discarded, representing a presumably large source of underutilized bioactive biomass. In this investigation, the polyphenol profiles of tropical highland strawberry (Fragaria x ananassa cv. Festival) leaves and fruits were compared by high-performance liquid chromatography coupled with a diode array detector (UHPLC-DAD) and mass spectrometry (HPLC-MS). The total polyphenol strawberry leaf extracts exhibited a 122-fold-higher total polyphenol content and 13-fold higher antioxidant activity (ORAC) than strawberry fruits, and they showed evidence of possible photoprotective effects against UV damage in human melanoma cells (SK-MEL-28) and in murine embryo fibroblasts (NIH/3T3), together with promising anti-proliferative activities against the same melanoma cells. Seven polyphenols were confirmed by HPLC-DAD in the leaf extracts, with differences depending on fraction solubility. Moreover, three substituted quercetin derivatives, three substituted kaempferol derivatives, two anthocyanins, and catechin were confirmed in the soluble fraction by HPLC-MS. Given their higher total polyphenol content and bioactive activities, underutilized strawberry Festival leaves are a potential source of apparently abundant biomass with prospective bioactive applications.

Impact of different processing methods on the phenolics and neuroprotective activity of Fragaria ananassa Duch. extracts in a D-galactose and aluminum chloride-induced rat model of aging

Age-related diseases, including dementia, are a major health concern affecting daily human life. Strawberry (Fragaria ananassa Duch.) is the most eaten fruit worldwide due to its exceptional aroma and flavor. However, it's rapid softening and decay limit its shelf-life. Freezing and boiling represent the well-known conservation methods to extend its shelf-life. Therefore, we aimed to discover the phytochemical content differences of fresh and processed strawberries associated with investigating and comparing their neuroprotective effects in a rat model of aging. Female Wistar rats were orally pretreated with fresh, boiled, and frozen F. ananassa methanolic extracts (250 mg kg-1) for 2 weeks, and then these extracts were concomitantly exposed to D-galactose [65 mg kg-1, subcutaneously (S/C)] and AlCl3 (200 mg kg-1, orally) for 6 weeks to develop aging-like symptoms. The results of UPLC/ESI-MS phytochemical profiling revealed 36 secondary metabolites, including phenolics, flavonoids, and their glycoside derivatives. Compared with boiled and frozen extracts, the fresh extract ameliorated the behavioral deficits including anxiety and cognitive dysfunction, upregulated brain HO-1 and Nrf2 levels, and markedly reduced caspase-3 and PPAR-γ levels. Moreover, LDH and miRNA-9, 124 and 132 protein expressions were reduced. The histological architecture of the brain hippocampus was restored and glial fibrillary acidic protein (GFAP) immunoexpression was downregulated. In conclusion, the fresh extract has neuroprotective activity that could have a promising role in ameliorating age-related neurodegeneration.

Are There as Many Essential and Non-essential Minerals in Hydroponic Strawberry (Fragaria ananassa L.) Compared to Those Grown in Soil?

The present study aims to compare the contents of minerals (essential major-K, Ca, Mg, Na, P, S; essential trace-Fe, Mn, Zn, Cu, B, Mo, As, Se, Ni, V, Cr, Co; non-essential-Sn, Ga, Li, Be, Rb, Sr, Al, Pd, Cd, Hg, Pb, Ge) in strawberry (stem, leaf, and fruit) cultivated in two different cultivation systems, soil and hydroponic. The concentrations of 30 minerals in the acid-digested strawberry samples were determined by ICP-MS and ICP-OES. Hydroponic strawberry (leaf > fruit > stem) indicated higher values for most minerals which were below the plant toxicity levels. In leaves collected from the hydroponic system, it was observed there were larger amounts of Fe, Zn, B, As, Se, Ni, V, Cr, Al, Cd, and Pd. Hydroponic fruits were the significant sources of K, P, Mn, Zn, Cr, and Co. Hydroponic strawberry leaves could contribute twice as many higher and safe daily intake of minerals to humans than other fruits. This analysis shows that, firstly, higher quality and safely edible produce can be provided by the hydroponic system; and secondly, strawberry leaf is a potential mineral source.