Polyphenols profile and in vitro biological activities of black goji berries (Lycium ruthenicum Murr.)

BACKGROUND: Due to the presence of wide-range phytochemicals, particularly anthocyanins, and their health-promoting activities, black goji fruits (Lycium ruthenicum Murr., LRf) gained attention as functional foods or nutraceuticals. However, data on the phytochemical composition and bioactivities of LRf from outside Asian countries are very limited. OBJECTIVE: This study reports the polyphenols profile and in vitro biological activities of LRf cultivated in the southern part of Serbia. METHODS: The total content of polyphenols, flavonoids and anthocyanins of LRf was determined spectrophotometrically, while the polyphenol profile was evaluated by LC-DAD-ESI-MS. Antioxidant and enzyme-inhibitory potentials against alpha-amylase, alpha-glucosidase, acetylcholinesterase, tyrosinase, and 15-lipoxygenase properties were determined spectrophotometrically. The prebiotic potential was assessed by the broth microdilution method. RESULTS: Chromatographic analysis confirmed that hydroxycinnamic acid derivatives and acylated anthocyanins were the predominant polyphenols of LRf. In addition to antioxidative activities, Lycium ruthenicum methanol extract (LRe) showed inhibitory effects against all tested enzymes (IC50 = 5.28-7.28 mg/mL). Prebiotic potential on the growth of various microorganisms' species was observed, with a marked effect on the growth of yeast Saccharomyces boulardii. CONCLUSIONS: The polyphenol pattern of LRf cultivated in Serbia corresponds with the literature data. Observed bioactivities support further phytochemical characterizations of LRf and investigations of their health-promoting effects, especially prebiotic properties.