Skin Sensitization Test
Guinea pigs (both sexes, 6-7 weeks, 330-410 g) were purchased from
Pizhou Orient Breeding (Jiangsu, China) and randomly assigned into three
groups (n=10). The back hair was removed before the skin sensitization
test. The Control group was treated with a blank solvent, and the
allicin-treated group received topical allicin treatment (4 mg/g,
measured with alliin). In the positive control group, 1-chloro-2,
4-dinitrobenzene (WT6CA-VO, Tokyo Chemical Industry) was used as a
contact-sensitizing agent; a 1% sensitization concentration solution or
0.1% excitation concentration was prepared with ethanol. On
sensitization day, guinea pigs were treated on the left skin, and on the
excitation day were treated on the right skin. The first sensitization
and administration day was defined as the first day of the test (D1).
Guinea pigs were sensitized on Days 1, 8 and 15), and all groups were
stimulated 14 days after the last sensitization (D29). The allergic
reactions of the skin were observed at 6 h, 24 h, 48 h, and 72 h. Skin
anaphylaxis includes erythema and edema. The evaluation criteria of
erythema: without erythema (0), barely visible erythema (1), visible
erythema (2), severe erythema (3), purplish-red erythema with mild
eschar (4); The evaluation criteria of edema: without edema (0), barely
visible edema (1), obviously higher than the edge of the surrounding
skin (2), skin bulge 1mm or clear contour (3), skin bulge more than 1mm
or blisters or ulceration (4).