Bioactive properties of combined leaf wastes from Rubus ulmifolius and Prunus persica: antioxidant and anti-inflammatory activities

Prunus persica and Rubus ulmifolius, both belonging to the Rosaceae family, are widely recognized for their fruits rich in valuable natural compounds. Thus, this study aimed to assess the antioxidant and anti-inflammatory properties of their leaves, usually considered as waste, in the form of a single extract. Extracts were obtained by using a mixture of acetonitrile, distilled water, and formic acid in the presence of ultrasound. A phytochemical characterization of the samples by reverse-phase HPLC–DAD and spectrophotometric approaches was carried out, revealing a high content of 5,7-dimethoxycoumarin, quercetin, genistein, and salicylic acid. Then, antiradical and anti-inflammatory in vitro assays revealed that these extracts presented a good capacity to act as free radical scavengers and to reduce inflammation. However, a molecular docking study specifically demonstrated that R. ulmifolius extract possessed the highest anti-inflammatory potential due to its significant level of quercetine-3-glucoside, which was predicted to have an elevated binding affinity for Lipoxygenase enzyme. By and large, recycling leaves from the two investigated plant species after fruit harvesting could be a sustainable way to obtain important sources of nutraceuticals employable in food, cosmetic, pharmaceutical, and medical industries.