Pappalardo G, Maiani G, Mobarhan S, Guadalaxara A, Azzini E, Raguzzini A, Salucci M, Serafini M, Trifero M, Illomei G, Ferro-Luzzi A
Institute of II Clinica Chirurgica University of Rome La Sapienza, Italy.
Eur J Clin Nutr. 1997 Oct;51(10):661-6. doi: 10.1038/sj.ejcn.1600457.
(1) To compare tissue and plasma carotenoids status of healthy subjects and subjects with pre-cancer and cancer lesions; (2) to evaluate the effect of beta-carotene supplementation on the concentrations of other carotenoids in tissue (luteine + zeaxanthin, cryptoxanthin, lycopene, alpha-carotene) and in plasma and also retinol and alpha-tocopherol levels.
Eighteen subjects were divided into three groups on the basis of colonoscopy and histological analytical findings: four healthy subjects (control group A); seven subjects affected by adenomatous polyps (group B with pre-cancer lesions); seven subjects suffering from colonic cancer (group C). Blood and colonic biopsy samples were taken (of colon and rectal mucosa) before and after beta-carotene supplementation in all subjects. Groups A and B received a daily dose of beta-carotene (30 mg/die) for 43 d. Group C's supplementation was terminated at the time which was performed, usually within 15 d. The tissue and plasma concentration of carotenoids, retinol and alpha-tocopherol were determined by high-performance liquid chromatography.
The tissue concentrations of each carotenoid were similar in all the intestinal sites examined as regards groups A and B, although there was a high degree of intra individual variability within each group. Only beta-carotene made significant increases (P < 0.001) after supplementation. The subjects with cancer show tissue levels for each carotenoid lower than those of healthy subjects or subjects with polypous. The plasma levels of alpha-tocopherol did not change after supplementation while significant increases were noted of retinol, alpha-carotene (P < 0.01) and of beta-carotene (P < 0.001).
The patients with colonic cancer seemed to undergo a significant reduction in their antioxidant reserves with respect to the normal subjects and or polyps. We can confirm that oral B-carotene supplementation induces also an increase in plasma alpha-carotene in all groups.
（1）比较健康受试者与癌前病变及癌症患者的组织和血浆类胡萝卜素水平；（2）评估补充β-胡萝卜素对组织（叶黄素+玉米黄质、隐黄质、番茄红素、α-胡萝卜素）和血浆中其他类胡萝卜素浓度以及视黄醇和α-生育酚水平的影响。
根据结肠镜检查和组织学分析结果，将18名受试者分为三组：四名健康受试者（A对照组）；七名患有腺瘤性息肉的受试者（有癌前病变的B组）；七名患有结肠癌的受试者（C组）。在所有受试者补充β-胡萝卜素之前和之后采集血液和结肠活检样本（结肠和直肠黏膜）。A组和B组每天服用β-胡萝卜素（30毫克/天），持续43天。C组的补充在进行时终止，通常在15天内。通过高效液相色谱法测定类胡萝卜素、视黄醇和α-生育酚的组织和血浆浓度。
就A组和B组而言，在所检查的所有肠道部位，每种类胡萝卜素的组织浓度相似，尽管每组内个体差异程度较高。补充后只有β-胡萝卜素显著增加（P<0.001）。癌症患者的每种类胡萝卜素组织水平低于健康受试者或息肉患者。补充后α-生育酚的血浆水平没有变化，而视黄醇、α-胡萝卜素（P<0.01）和β-胡萝卜素（P<0.001）显著增加。
与正常受试者和/或息肉患者相比，结肠癌患者的抗氧化储备似乎显著减少。我们可以确认，口服β-胡萝卜素补充剂在所有组中也会导致血浆α-胡萝卜素增加。
