Phenolic Profiles and Biological Activities of Extracts from Edible Wild Fruits Ehretia tinifolia and Sideroxylon lanuginosum

Abstract

<i>Ehretia tinifolia</i> Linnaeus (Boraginacea) and <i>Sideroxylon lanuginosum</i> Michaux (Sapotaceae) are wild fruits consumed in North America and are appreciated for their pleasant flavor and sweet taste. However, details regarding their composition and biological properties in the available literature are scarce. This study reports the phenolic composition, antioxidant, antiproliferative activities, and digestive enzymatic inhibition of amberlite-retained methanolic extracts from both fruits. Results revealed that these wild fruit extracts are rich in antioxidants. <i>S. lanuginosum</i> had lower phenolic but higher flavonoid contents (21.4 ± 1.5 mg GAE/100 g FW and 6.42 ± 0.9 mg CE/100 g FW) than <i>E. tinifolia</i> (64.7 ± 2.6 mg GAE/100 g FW and 5.1 ± 0.4 mg CE/100 g FW). HPLC-DAD-MS/MS analysis showed rosmarinic acid as a major polyphenol in <i>E. tinifolia</i> and quercetin glucoside in <i>S. lanuginosum</i>. Polyphenols content in <i>E. tinifolia</i> was related to a significant free radical scavenging ability: DPPH (EC₅₀ = 0.32 ± 0.03 mg/mL), TEAC (4134 ± 9.7 μM TE/g dry extract), and hemolysis inhibition (IC₅₀ = 58.55 ± 2.4 μg/mL). Both extracts were capable of inhibiting <i>α</i>-glucosidase, partially inhibiting <i>α</i>-amylase, and showed no inhibition against lipase, while showing antiproliferative activity against HeLa, HT-29 and MCF-7 cancer cell lines. Our study revealed that these wild fruit extracts are rich in health-beneficial phytochemicals and hold significant potential for elaborating functional foods.