Reeve V E, Bosnic M, Rozinova E, Boehm-Wilcox C
Department of Veterinary Pathology, University of Sydney, New South Wales, Australia.
Photochem Photobiol. 1993 Dec;58(6):813-7. doi: 10.1111/j.1751-1097.1993.tb04975.x.
Lyophilized aged garlic extract has been incorporated at concentrations of 0.1%, 1% and 4% by weight into semipurified powdered diets and fed to hairless mice. Under moderate UVB exposure conditions resulting in 58% suppression of the systemic contact hypersensitivity response in control-fed mice, a dose-responsive protection was observed in the garlic-fed mice; contact hypersensitivity in the UVB-exposed mice fed 4% garlic extract was suppressed by only 19%. If the UVB exposure was replaced by topical application of one of a series of lotions containing increasing concentrations of cis-urocanic acid, a dose-responsive suppression of contact hypersensitivity was demonstrated in control-fed mice (urocanic acid at 25, 50, 100 and 200 micrograms per mouse resulting in 22-46% suppression). Mice fed a diet containing 1% aged garlic extract were partially protected from cis-urocanic acid-induced suppression of contact hypersensitivity, with greater protection from the lower concentrations of urocanic acid. Mice fed a diet containing 4% aged garlic extract were protected from all concentrations of urocanic acid. The results indicate that aged garlic extract contains ingredient(s) that protect from UVB-induced suppression of contact hypersensitivity and suggest that the mechanism of protection is by antagonism of the cis-urocanic acid mediation of this form of immunosuppression.
将冻干的陈年大蒜提取物按重量浓度0.1%、1%和4%掺入半纯化的粉状饲料中，喂给无毛小鼠。在中等强度紫外线B（UVB）照射条件下，对照饲料喂养的小鼠全身接触性超敏反应受到58%的抑制，而喂食大蒜的小鼠则呈现出剂量依赖性保护作用；喂食4%大蒜提取物的UVB照射小鼠的接触性超敏反应仅受到19%的抑制。如果用局部涂抹一系列含不同浓度顺式尿刊酸的洗剂替代UVB照射，对照饲料喂养的小鼠呈现出剂量依赖性的接触性超敏反应抑制（每只小鼠使用25、50、100和200微克顺式尿刊酸导致22%-46%的抑制）。喂食含1%陈年大蒜提取物饲料的小鼠对顺式尿刊酸诱导的接触性超敏反应抑制有部分保护作用，对较低浓度的顺式尿刊酸保护作用更强；喂食含4%陈年大蒜提取物饲料的小鼠对所有浓度的顺式尿刊酸均有保护作用。结果表明，陈年大蒜提取物含有可防止UVB诱导的接触性超敏反应抑制的成分，并提示其保护机制是通过拮抗顺式尿刊酸介导的这种免疫抑制形式。
