A Preliminary Study On Factors To Have Influence On Lycopene Absorption And Metabolism And The Biological Function Of Metabolites

Objectives:This study aims to investigate into the metabolism and biological functions of natural lycopene in vivo with following experiments:[1]The influence of cooking conditions on the absorption of lycopene in rat;[2]Accumulation of lycopene in the serum,liver,prostate and adrenal gland of rat;[3]The influence of hormones on lycopene transportation and storage in rat; [4]The regulation of lycopene on serum hormone levels in rat;[5]The effect of lycopene on the growth of PC-3 cell,a prostate tumor cell strain.Method and materials:For investigation into the influence of cooking conditions upon the absorption of lycopene,two Chinese cooking methods,fry and boiling,were employed in this study.The lycopene amount and geometrical isomer composition from cooked tomato meals were assessed by C30-HPLC-PDA.All of animal trials from this study were performed in the SPF animal house of the College of Applied Art and Science,Beijing Union University.Experimentally,male and female rats were selected with the body weight of 200-250g and divided randomly into a number of groups, respectively.Each group consisted of at least 6 individuals for a statistically reliable observation. Gastric administration solutions were prepared from natural lycopene extract and salad oil with the final lycopene amount of low,medium and high dose.After a single dose(usually 1ml) gastric administration,the blood,liver and prostate gland of each rat were collected at fixed time.Total carotenoids were extracted from collected samples and assessed for lycopene amount by UV-VIS and HPLC.The serum hormone level of rats was assessed.Assay on the degradation pieces of lycopene molecules from rat prostate gland was performed by HPLC and MS.In refer to results from the assessment,the decomposition pieces of natural lycopene were chemically prepared.PC-3 cells were cultured with the mixture of decomposed pieces.The influence of decomposed pieces on the growth was observed.Results and discussion:Data from experiment[1]suggested that Chinese cooking had a limited influence on total carotenoid amount of tomato piece while frying with oil was beneficial for lycopene releasing from the tissue and Z-isomerisation.It was observed from investigations[2-4]that the maximum accumulation of lycopene from the serum and liver of male rat appeared more quickly and was higher than that of female rat, respectively.After surgery,the maximum accumulation of lycopene from the serum of female rat increased significantly while that from liver decreased considerably and kept near constantly in 8-24 hours.Furthermore,it was observed that a single dose gastric administration was able to induce an increase in the serum testosterone level of male rat and the serum estradiol level of female rat.Data from those experiments suggested that(1) the metabolism of lycopene was quicker in male rat than that in female rat;(2) The metabolism of lycopene was influenced by hormones from female rat.The short of female hormones was able to promote the metabolism of lycopene in female rat;(3) By contrast,lycopene was also able to regulate some female hormones from serum.Data from experiment[5]exhibited that the mixture of decomposed pieces could restrain the growth of CP3 cell.