Apigenin is found in high amounts in several herbs including parsley, thyme, and peppermint.
It has been reported as an important dietary flavonoid with strong anti-inflammatory
activities [1]. It is extensively metabolized and mainly eliminated in humans by first-pass
metabolism via glucuronidation and sulfation [2,3]. The aim of this study was to improve
the anti-inflammatory activities of apigenin through co-treatment with resveratrol
as a bioenhancer of apigenin. RAW 264.7 cells pretreated with hepatic metabolites
formed by the co-metabolism of apigenin and resveratrol (ARMs) in HepG2 cells were
stimulated with lipopolysaccharide (LPS). ARMs prominently inhibited (p < 0.05) the
production of nitric oxide (NO), prostaglandin E2 (PGE2), interleukin (IL)-1β, IL-6 and TNF-α. Otherwise no such activity was observed by
hepatic metabolites of apigenin alone (AMs). ARMs also effectively suppressed protein
expressions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2).
Co-administration of apigenin (50 mg/kg) and resveratrol (25 mg/kg) also showed a
significant reduction of carrageenan-induced paw edema in mice (61.20% to 23.81%).
These results suggested that resveratrol helps apigenin to bypass hepatic metabolism
and maintain apigenin's anti-inflammatory activities in the body.
Acknowledgements: This study was supported by research program of Korea food research
institute.
Keywords: anti-inflammation, bioenhancer, hepatic metabolites of apigenin, UDP-glucuronosyltransferase
(UGT).
References:
[1] Nicholas C, Batra S, Vargo MA, Voss OH, Gavrilin MA, Wewers MD, Guttridge DC, Grotewold
E, Doseff AI. Apigenin blocks lipopolysaccharide-induced lethality in vivo and proinflammatory cytokines expression by inactivating NF-kappaB through the suppression
of p65 phosphorylation. J Immunol 2007; 179: 7121 – 7127
[2] Nielsen SE, Dragsted LO. Column-switching high-performance liquid chromatographic assay for determination
of apigenin and acacetin in human urine with ultraviolet absorbance detection. J Chromatogr
B Biomed Sci Appl 1998; 713: 379 – 386
[3] Havsteen BH. The biochemistry and medical significance of the flavonoids. Pharmacol Ther 2002;
96: 67 – 202
