PENGARUH VITAMIN C TERHADAP ABSORPSI SENG SECARA IN VITRO (The effect of vitamin C on zinc absorption as measured by in vitro study)

Abstract

The objective of this research is to study the level of zinc absorption caused by adding Ascorbic acid (vitamin C) especially to know the percentage of zinc can be absorbed with and without vitamin C addition, and the amount of vitamin C has to be added in order to get an optimal absorption of zinc The modification of Wilson-Wiseman's method to study the transport of substances across the intestinal membrane is used in this research. Samples are 35 small intestines of male white leghorn 6 weeks old chicks that are devided into 5 groups. Each group respectives 220 mg ZnSO4, 220 mg ZnSO4+150 mg vitamin C, 220 mg ZnSO4+300 mg vitamin C, 220 mg ZnSO4+450 mg vitamin C and 220 mg ZnSO4+600 mg vitamin C diluted in Ringer solution up to 10,0 ml. Fill one ml of dilution sample into 10 cm intestine bag, insert bag into 1.000 ml beaker glass filled by Ringer solution and keep at 37 0C for 60 minutes. Withdraw amount of Ringer solution from the beaker glass and extract with Dithizon reagent then read it in spectrophotometer at 535 nm wavelength and calculates by extrapolating standard curve, Y= 3.679,23 X — 0,019. Also reads the pH of each combinations. Percentage of zinc absorption is aproximately 10,28 (+2,80) with the optimal absorption time at 60th minutes. The recovery concentration of zinc are 11,82 (±0,90), 15,91 (±1,00), 21,15 (±3,93), 17,57 (±3,06) and 16,22 (±2,42) %. This experiment shows that treatment by vitamin C caused decrease pH solution and affect on increasing zinc absrption. Statistically, one way Anova give Feal = 10,36 > Ftab. = 2,76 {P=0,05, df (4,25)}. Therefore the hipothesis, Ho, is rejected. It means that there is significant different between combination with than without vitamin C. Adding 300 mg vitamin C give recovery result significantly better than the others. The conclusions of this research are (1) zinc absorbed from intestine is 10,28 + 2,80 %; (2) peak time absorption is at 60th menutes; (3) the optimal combination is 220 mg ZnSO4+300 mg vitamin C and pH optimal is at 2,47; and (4) percentage of increasing recovery is 178,93 %. ABSTRAK Telah dilakukan penelitian Pengaruh vitamin C terhadap absorpsi seng secara in vitro, bertujuan untuk mengkaji tingkat absorpsi seng dengan adanya penambahan vitamin C Khususnya mengkaji rekoveri absorpsi seng di dalam usus baik dengan maupun tanpa penambahan vitamin C dan untuk mengetahui jumlah vitamin C yang ditambahkan agar absorpsi seng mencapai optimal. Metoda yang digunakan adalah modifikasi metoda Wilson-Wiseman dengan menggunakan 35 usus ayam White leghorn jantan umur 6 minggu, dibagi dalam lima kelompok perlakuan yaitu penambahan 0, 150, 300, 450 dan 600 mg vitamin C masing-masing pada 220 mg ZnSO4 dilarutkan dengan larutan Ringer hingga 10,0 ml. Larutan sampel 1,0 ml dimasukkan ke dalam kantong usus sepanjang 10 cm, dicelupkan kedalam larutan Ringer 1.000 ml, dihangatkan pada suhu 370C selama 60 menit. ' Cairan bagian luar kantong diambil dan kadar seng ditetapkan secara spektrofotometri metoda Dithizon pada panjang gelombang 535 nm. Kadar dihitung menggunakan kurva baku, Y=3.679,23 X - 0,019. Diukur pula pH masing-masing kombinasi ZnSO4-vitamin C dan pH vitamin C perlakuan. Kadar rekoveri seng yang diabsorpsi di usus 10,28 (+2,80)% dengan waktu absorpsi optimal pada menit ke 60. Dui hasil penelitian diperoleh rata-rata kadar rekoveri seng masing-masing kombinasi 220 mg ZnSO4 dengan 0,150, 300, 450 dan 600 mg vitamin C adalah 11,82(+0,90), 15,91(+1,00), 21,15(+3,93), 17,57(+3,06) dan 16,22(±2,42) %. Uji statistik menggunakan Anova satu jalan diperoleh Fc.91 = 10,36 > Fthb.=2,76 {P=0,05;df--(4,25)}, Ho ditolak, berarti ada perbedaan bermakna antara penambahan dibanding tanpa penambahan vitamin C, tidak ada perbedaan bermakna antara penambahan 150, 450 dan 600 mg, tetapi dengan 300 mg vitamin C memberikan hasil rekoveri lebih baik dan berbeda secara bermakna dibanding dengan perlakuan lain. Dari hasil percobaan tersebut dapat disimpulkan bahwa prosentase seng yang diserap oleh usus sebesar 10,28(+2,80) % dengan waktu absorpsi mencapai puncak pada menit ke 60. Vitamin C yang ditambahkan agar absorpsi seng maksimal sebanyak 300 mg, terjadi pada pH 2,47 dan diperoleh kenaikan absorpsi sebesar 178,93%.