Concentration-Dependent Bioactivity Profiles of Hesperetin and Naringenin: Insights into Antibacterial, Antioxidant, and Anti-Inflammatory Effects

Abstract

This study examines the concentration-dependent bioactivity profiles of hesperetin and naringenin, two naturally occurring flavonoids found in citrus fruits. Our findings elucidate pivotal insights into their antibacterial, antioxidant, and anti-inflammatory effects. A comprehensive series of experiments involving microbiological, biochemical, and cellular methods was conducted to demonstrate that the bioactivities of these compounds are significantly influenced by their concentrations. It is noteworthy that hesperetin exhibits concentration-dependent antibacterial activity against a broad spectrum of bacteria, including Escherichia coli, Staphylococcus aureus, and Streptococcus mutans, while naringenin shows varying degrees of inhibition depending on the bacterial species. Additionally, hesperetin demonstrates superior antioxidant capacity compared to naringenin, as evidenced by its higher DPPH radical scavenging activity. Moreover, both compounds have been observed to promote the proliferation of RAW 264.7 cells at low concentrations, yet exhibit inhibitory effects at higher doses. It is noteworthy that both hesperetin and naringenin effectively suppress the expression of inflammation-related genes, including TNF-α, IL-1β, and iNOS, in RAW 264.7 macrophages. This highlights their potential as anti-inflammatory agents. These outcomes provide valuable information for optimizing the use of hesperetin and naringenin in the pharmaceutical and food industries, contributing to the advancement of flavonoid research and offering a foundation for future applications.