o:34037 Assessment of sun protecting factor and in vitro cytotoxicity of methanolic pulp extracts from Serbian Cucurbita maxima in human keratinocytes en Ultraviolet radiation from sun exposure causes harmful skin effects, such as dermal photoaging and DNA damage, mediated by oxidative stress. Pumpkin (Cucurbita maxima) is abundant in carotenoids, polyphenols, and tocopherols which have antioxidant ability and protect cells from damage making them attractive as potential natural photo-protectants for skin applications. Pumpkin pulp, considered as by-product of the food industry, is the least explored in terms of its biological activities, although it contains considerable amounts of bioactive compounds. The aim of this study was to evaluate in vitro sun protecting factor (SPF) and cytotoxicity of methanolic pumpkin pulp extracts (MPE). They were prepared from the material of 4 accessions MAX 113, MAX 118-1, MAX 117, and MAX 1 from the breeding collection of the Institute of Field and Vegetable Crops, Novi Sad, Serbia. These accessions were selected according to the highest carotenoid content and antioxidant capacity. The effect of MPE on human keratinocytes (HaCaT) viability was determined by crystal violet assay. In vitro SPF based on the Mansur equation and the absorbance measurements was chosen to screen the photoprotective potential of MPE. The results show that SPF values for extracts MAX 113, MAX 118-1, MAX 117, and MAX 1 were 2.351, 1.875, 4.573, and 3.812, respectively. The most pronounced in vitro SPF values were in extracts MAX 117 and MAX 1 which were previously shown to contain the high amounts of carotenoids zeaxanthin and β-carotene. In vitro study of cell viability in keratinocytes showed that MAX 118- 1, MAX 117, and MAX 1 did not reduce the number of viable cells up to the concentration of 1000 µg/mL and thus might be considered as non-toxic. Among the analyzed extracts, extract MAX 113 reduced HaCaT cells viability after 24 h incubation in a concentration-dependent manner, where the highest concentration of 1000 µg/mL significantly reduced number of viable cells compared to the non-treated control. On the other hand, the treatment of keratinocytes using extract MAX 117 led to a significant increase in the number of viable cells at 1000 µg/mL concentration. That was the same extract that exhibited the highest SPF value. These data demonstrate that bioactive compounds from MPE could have potential as anti-photoaging agents and can be considered as non-toxic for the skin cells. Additionally, findings suggest MPE of C. maxima Duchesne cultivar MAX 117 from Serbian accession has the best photoprotective potential and could be useful as component in natural cosmetic products. 2024-06-17T15:14:37.973Z 44 yes 46 Dragana Dekanski University of Belgrade, Institute for the Application of Nuclear Energy, Serbia doktor medicinskih nauka 0000-0001-8467-4165 Aleksandra Jovanović University of Belgrade, Institute for the Application of Nuclear Energy, Serbia doktor tehnoloških nauka person 0000-0001-5394-0125 Milorad Miljić University of Novi Sad, Faculty of Sciences, Department of Chemistry, Biochemistry and Environmental Protection, Novi Sad, Serbia, Institute of Food Technology (FINS), Novi Sad, Serbia person Sanja Krstić University of Graz, Institute of Pharmaceutical Sciences, Graz, Austria person Andrea Pirković University of Belgrade, Institute for the Application of Nuclear Energy, Serbia doktor bioloških nauka person 0000-0002-1182-4895 application/pdf 325861 https://phaidrabg.bg.ac.rs/o:34037 no yes 19 70 92000004 11A29 11A2901 11A29 11A2910 Assessment of sun protecting factor and in vitro cytotoxicity of methanolic pulp extracts from Serbian Cucurbita maxima in human keratinocytes PP209 Book of Abstracts of 9th European Congress of Pharmacology, EPHAR2024, Athens, Greece 2024