Antioxidant and Anti-Inflammatory Potential of Hesperetin Metabolites Obtained from Hesperetin-Administered Rat Serum: An Ex Vivo Approach

Abstract

In recent years much attention has been focused on the pharmaceutical relevance of bioflavonoids, especially hesperidin and its aglycon hesperetin in terms of their antioxidant and anti-inflammatory actions. However, the bioactivity of their metabolites, the real molecules in vivo hesperetin glucuronides/sulfates produced after ingestion, has been poorly understood. Thus, the study using an ex vivo approach is aimed to compare the antioxidant and anti-inflammatory activities of hesperidin/hesperetin or hesperetin metabolites derived from hesperetin-administered rat serum. We found that hesperetin metabolites (2.5-20 μM) showed higher antioxidant activity against various oxidative systems, including superoxide anion scavenging, reducing power, and metal chelating effects, than that of hesperidin or hesperetin. The data also showed that pretreatment of hesperetin metabolites (1-10 μM) within the range of physiological concentrations, compared to hesperetin, significantly inhibited nitric oxide (NO) and prostaglandin E(2) (PGE(2)) production, as evidenced by the inhibition of their precursors, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein levels without appreciable cytotoxicity on LPS-activated RAW264.7 macrophages or A7r5 smooth muscle cells. Concomitantly, hesperetin metabolites dose-dependently inhibited LPS-induced intracellular reactive oxygen species (ROS). Furthermore, hesperetin metabolites significantly downregulate LPS-induced nuclear factor-κB (NF-κB) activation followed by the suppression of inhibitor-κB (I-κB) degradation and phosphorylation of c-Jun N-terminal kinase1/2 (JNK1/2) and p38 MAPKs after challenge with LPS. Hesperetin metabolites ex vivo showed potent antioxidant and anti-inflammatory activity in comparison with hesperidin/hesperetin.

Multidrug Resistance-Associated Protein 4 (MRP4/ABCC4) Controls Efflux Transport of Hesperetin Sulfates in Sulfotransferase 1A3–Overexpressing Human Embryonic Kidney 293 Cells

“…Elucidating the transport mechanisms for phase II conjugates (sulfates and glucuronides) of hesperidin assumes great importance because 1) these hydrophilic conjugates are the main circulating metabolites; and 2) the conjugates possess many types of biologic activities, such as antioxidant and anti-inflammatory effects (Proteggente et al, 2003;Trzeciakiewicz et al, 2010;Yang et al, 2012;Yamamoto et al, 2013;Gamo et al, 2014). It has been shown that multiple transporters (BCRP, MRP2, and MRP3) are potentially responsible for efflux transport of hesperetin glucuronides (Brand et al, 2008(Brand et al, , 2011.…”

Evaluation of topical hesperetin matrix film for back-of-the-eye delivery

“…In terms of anti-inflammatory activity, Yang et al reported that at 1-10 μM (0.3 – 3.02 μg/mL) HT concentrations, cellular levels of COX-2 and PEG2 are markedly attenuated [44]. With both the 10% and 20 %w/w films, HT levels in the AH (1.2 and 3.4 μg/mL, respectively) were maintained within the concentration range required for COX-2 and PEG2 inhibition, even at the end of 3h.…”

Arylsulfatase B Mediates the Sulfonation-Transport Interplay in Human Embryonic Kidney 293 Cells Overexpressing Sulfotransferase 1A3

“…Hesperetin is extensively metabolized by phase II enzymes to form sulfate and glucuronide conjugates, resulting in exceedingly low bioavailability after oral administration (Brand et al, 2008(Brand et al, , 2010. Recent studies have indicated that phase II conjugates of hesperetin retain the biologic activities of the parent molecule (Takumi et al, 2012;Yang et al, 2012). This helps to explain why oral hesperetin has in vivo activities despite the fact that the compound is the least bioavailable (Giménez-Bastida et al, 2016).…”