Inhibitory Effects of Tea Catechins andO-Methylated Derivatives of (−)-Epigallocatechin-3-O-gallate on Mouse Type IV Allergy

Abstract

The inhibitory effects of tea catechins, the O-methylated derivatives of (-)-epigallocatechin-3-O-gallate (EGCG), and the polyphenol extracts from tea leaves (Camellia sinensis L.) on oxazolone-induced type IV allergy in male ICR mice were investigated. Four major tea catechins and two O-methylated derivatives, (-)-epigallocatechin-3-O-(3-O-methyl)gallate (EGCG3' 'Me) and (-)-epigallocatechin-3-O-(4-O-methyl)gallate (EGCG4' 'Me), showed significant inhibitory effects on mouse type IV allergy after a percutaneous administration at a dose of 0.13 mg/ear. Among tea catechins, the compounds including galloyl moieties, such as EGCG and (-)-epicatechin-3-O-gallate (ECG), showed the strongest inhibitory activities on mouse type IV allergy. The inhibitory activities of EGCG3' 'Me and EGCG4' 'Me were higher than that of EGCG at a dose of 0.05 mg/ear. Polyphenol extract from tea leaves of Benihomare cultivar, which includes EGCG3' 'Me, strongly inhibited mouse type IV allergy after percutaneous administration in comparison with that from Yabukita cultivar, which does not include EGCG3' 'Me, at doses of 0.05 and 0.13 mg/ear. EGCG3' 'Me is thought to contribute, at least in part, to the inhibitory ability of Benihomare tea leaves on mouse type IV allergy. EGCG and the polyphenol extracts from Benihomare and Yabukita tea leaves also inhibited mouse type IV allergy by oral administration at 1 h before the sensitization and at 1 h before the challenge with oxazolone. Therefore, daily intake of tea drinks could have potential to prevent type IV allergy.

Comparative studies on the physicochemical and antioxidant properties of different tea extracts

“…It was a complex mixture containing multiple compounds from simple phenolics, catechins to polysaccharides and complex thearubigins, many of which had been reported to have health functions such as antiallergic (Suzuki et al 2000), antioxidative (Jhoo et al 2005), antimutagenic and anticarcinogenic (Standley et al 2001), antiatherosclerotic (Yokozawa et al 2002), antibacterial (Yildirim et al 2000), and hypoglycemic (Zhou et al 2007) activities.…”

The Suppressive Effect of a Marine Carotenoid, Fucoxanthin, on Mouse Ear Swelling through Regulation of Activities and mRNA Expression of Inflammation-associated Enzymes

“…When mice were orally administered test samples, the examination was performed according to the procedure described by Suzuki et al (2000) with some modifications. Four-hundred microliters of test sample was orally administered 1 h prior to the spreading of 1% OXA (50 μL) on the abdominal region of a mouse as described above.…”

Small molecule-sensing strategy and techniques for understanding the functionality of green tea

“…58,59) The inhibitory effects of O-methylated EGCG on in vivo mouse type I and IV allergies more are potent than EGCG. 58,60) These catechins also strongly inhibited mast cell activation through the prevention of tyrosine phosphorylation (Lyn, Syk, and Btk) of cellular protein, histamine/leukotriene release, and interleukin (IL)-2 secretion after FcεRI cross-linking. 61) A double-blind clinical trial to treat allergic cedar pollinosis patients with "Benifuuki" green tea rich in EGCG3″Me showed promising results, such as significant relief of blowing the nose and itching eyes, when 1.5 g of tea powder mixed in water was consumed twice a day for 13 weeks.…”