Molecular Characterization of Prunus lusitanica L. Fruit Extracts and Their Health-Promoting Potential in Inflammation, Diabetes, and Neurodegenerative Diseases

Abstract

Prunus lusitanica L. is a shrub belonging to the genus Prunus L. (Rosaceae family) that produces small fruits with none known application. Thus, the aim of this study was to determine the phenolic profile and some health-promoting activities of hydroethanolic (HE) extracts obtained from P. lusitanica fruits, harvested from three different locations. Qualitative and quantitative analysis of extracts was performed using HPLC/DAD-ESI-MS and antioxidant activity was assessed by in vitro methods. Antiproliferative/cytotoxic activity was determined on Caco-2, HepG2, and RAW 264.7 cells, anti-inflammatory activity was assessed using lipopolysaccharide (LPS)-stimulated RAW 264.7 cells, and the antidiabetic, antiaging, and neurobiological action of extracts was determined in vitro by assessing their inhibitory effect against the activity of α-amylase, α-glucosidase, elastase, tyrosinase, and acetylcholinesterase (AChE). Results showed that P. lusitanica fruit HE extracts from the three different locations showed identical phytochemical profile and bioactivities, although small differences were observed regarding the quantities of some compounds. Extracts of P. lusitanica fruits contain high levels in total phenolic compounds, namely, hydroxycinnamic acids, as well as flavan-3-ols and anthocyanins, primarily cyanidin-3-(6-trans-p-coumaroyl)glucoside. P. lusitanica fruit extracts have a low cytotoxic/antiproliferative effect, with the lowest IC₅₀ value obtained in HepG2 cells (352.6 ± 10.0 μg/mL, at 48 h exposure), but high anti-inflammatory activity (50-60% NO release inhibition, at 100 μg/mL extract) and neuroprotective potential (35-39% AChE inhibition, at 1 mg/mL), and moderate antiaging (9-15% tyrosinase inhibition, at 1 mg/mL) and antidiabetic (9-15% α-glucosidase inhibition, at 1 mg/mL) effects. The bioactive molecules present in the fruits of P. lusitanica deserve to be further explored for the development of new drugs of interest to the pharmaceutical and cosmetic industry.

Keywords: Prunus lusitanica L.; anti-inflammatory activity; antioxidant activity; antiproliferative activity; natural bioactive compounds; neuroprotection.

Figure 1

Antiproliferative/cytotoxic effect of P. lusitanica L. fruit extracts on Caco-2 (A–C), HepG2 (D–F), and Raw 264.7 (G–I) cells, for two exposure times: 24 h (gray bars) and 48 h (dark-pink bars). Results are expressed as the mean ± SD (n = 4). * Statistically significant difference (p < 0.05) between the control and sample concentrations at respective incubation times; ^# statistically significant difference (p < 0.05) between exposure periods at the same concentration.

Figure 2

Anti-inflammatory activity of P. lusitanica L. fruit extracts expressed as the inhibition of nitric oxide (NO) release by LPS-stimulated RAW 264.7 cells. Results are expressed as the mean ± SD (n = 4 independent assays). * Statistical differences (p < 0.05) between samples and the positive control (LPS-stimulated cells not exposed to extracts); ^# statistical differences (p < 0.05) between concentrations of the same sample.