dition, the P. nigrum leaf extract showed in vivo anti-androgenic activity using the hair regrowth assay in testosterone sensitive male C57Black/6CrSlc strain mice.

Effect of 50% ethanolic extract of unripe fruits of Citrus unshiu (CU-ext) on type IV allergic reaction was examined by inhibitory activity of ear swelling of picryl chloride-induced contact dermatitis (PC-CD) in mice. Oral administration of CU-ext and subcutaneous administration of prednisolone showed inhibition of ear swelling during both induction and effector phases of PC-CD. The inhibitory activities of combinations of CU-ext (p.o.) and prednisolone (s.c.) during induction phase of PC-CD were more potent than those of CU-ext alone and prednisolone alone. Successive oral administration of hesperidin, a major flavanone glycoside of CU-ext, inhibited ear swelling during induction phase of PC-CD. The inhibitory activities of combinations of hesperidin (p.o.) and prednisolone (s.c.) were more potent than those of hesperidin alone and prednisolone alone. These results indicated that the combinations of prednisolone and CU-ext or hesperidin exerted a synergistic effect.

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During the course of our search for useful ingredients of cosmetics from natural resource, we have previously reported that Piper nigrum leaf extract showed both melanogenesis stimulation activity and testosterone 5a-reductase inhibitory activity and that (Ϫ)-cubebin (1) and (Ϫ)-3,4-dimethoxy-3,4-desmethylenedioxycubebin (2) were isolated as active lignan constituents. [1][2][3][4] It was suggested that these substances may be useful ingredients of hair-care cosmetics for prevention of gray hair and alopecia. As a part of our continuous study on P. nigrum leaf, we examined anti-allergic effect of the leaf, because hair care cosmetics having anti-allergic activity may be desirable. It has been reported that antiallergic effect of a botanical formulation 5) in which P. nigrum fruit was included. Anti-allergic activity of piperine, 6) a major alkaloid amide of P. nigrum fruit have been reported, but HPLC analysis revealed that the piperine content in the leaf was 0.00007%. 7) Moreover, we have not found any reports on anti-allergic effect of the leaf. In this paper, we describe in vivo anti-allergic effects of P. nigrum leaf extract against type I allergy model and type IV allergy model in mice. 2,4-Dinitrofluorobenzene (DNFB) has been shown to induce triphasic increase in ear thickness of mouse by the challenge after a passive sensitization with monoclonal antidinitrophenyl (DNP) IgE antibody. 8,9) This model serves as an animal model for type I allergy. 8,9) In addition, we used picryl chloride (PC)-induced contact dermatitis in mice as an animal model for type IV allergy.10) Inhibitory effects of Piper nigrum leaf extract, on histamine release were also examined by in vitro assay using compound 48/80-induced histamine release from rat peritoneal mast cells. MATERIALS AND METHODS Plant MaterialsPiper nigrum leaf was the same sample described in the previous paper. 1-4)Reagents 2,4-Dinitrofluorobenzene (DNFB), Ficoll, Hanks' balanced salt solution, olive oil, o-phthaldialdehyde, picryl chloride (PC), and sodium carboxymethyl cellulose (CMC · Na) were purchased from Nacalai Tesque (Tokyo, Japan). Sodium cromoglycate (SCG) was purchased from Funakoshi (Tokyo, Japan). Compound 48/80, dimethyl sodium salt (DMSO), prednisolone, monoclonal anti-DNP antibody and heparin sodium salt were purchased from Sigma (St. Louis, MO, U.S.A.). Other chemical reagents were reagent grade and were purchased from Wako Pure Chemical Industries, Ltd. unless otherwise noted.Preparation of PN-ext and Fractionation Methanolic extract of Piper nigrum leaf (PN-ext) was obtained according to the previous paper in yield of 14.0%. The powdered dry leaves (500 g) of P. nigrum were extracted with MeOH (5 lϫ3 times) for 1 h under reflux. Combined extracts were evaporated under reduced pressure to give a methanolic extract (PN-ext, 71.1 g). A part of PN-ext (69.6 g) was extracted with hexane (400 mlϫ3), and the organic layer was evaporated to give a hexane soluble fraction (17.3 g). The hexane insoluble part was extracted with EtOAc (300 mlϫ2). The E...

We investigated whether the efficiency of intestinal calcium (Ca) absorption was improved by concomitant ingestion of gum arabic (GA) in rats. We used the Ussing chamber method to clarify the effect of GA on upper and lower small intestinal absorption of Ca. Increased in vitro Ca permeation was observed in rats who ingested water with 7.5% GA for 10 days. These results suggested that administration of GA with Ca could increase the efficiency of oral Ca absorption.