KAJIAN PENGARUH CHITOSAN TERHADAP PROFILLIPOPROTEIN, FUNGSI ENDOTELIAL AORTA DAN ARTERIA KORONARIA TIKUS PUTIH SPRAGUE DAWLEY DIINDUKSI LEMAK TINGGI
SRI ISDADIYANTO,SSi, MSi, Prof. Sukarti Moeljopawiro, Ph.D.
2013 | Disertasi | S3 BiologiAterosklerosis merupakan penyebab kematian utama di negara berkembang dan melalui proses yang kompleks, melibatkan faktor genetik, faktor lingkungan dan berbagai tipe sel yang saling berpengaruh satu dengan yang lain. Lesi aterosklerotik diawali oleh adanya kerusakan sel-sel endotelia pembuluh darah. Tujuan penelitian ini adalah untuk mempelajari pengaruh pemberian chitosan terhadap profil lipoprotein, fungsi endotelial aorta, fungsi endotelial arteria koronaria dan ekspresi C-Reactive Protein tikus putih yang diinduksi lemak tinggi. Dua puluh ekor tikus putih Sprague Dawley jantan, umur 1,5 bulan digunakan sebagai hewan uji. Tikus putih diadaptasikan selama 1 minggu 1 ekor per kandang dengan pakan standar dan minum ad libitum. Tikus putih dibagi menjadi 4 kelompok 5 ekor per kelompok. Kelompok I diberi pakan dengan lemak normal selama penelitian. Kelompok II, III dan IV diberi pakan lemak tinggi. Kelompok II tanpa perlakuan. Kelompok III diberi chitosan 180 mg/ kg BB/ hari. Kelompok IV setelah satu bulan diberi chitosan dengan dosis yang sama dengan kelompok III. Chitosan diberikan peroral dalam larutan 2 ml aquades. Penelitian dilakukan selama 90 hari. Pada hari terakhir perlakuan, setiap tikus dipuasakan 12-14 jam sebelum darah diambil. Pengambilan darah melalui sinus orbitalis mata untuk analisis profil lipoprotein. Selanjutnya hewan dikorbankan dan di ambil organ jantung beserta aorta untuk pembuatan preparat histopatologis dan imunohistokimia (ekspresi CRP). Ada dan tidaknya perbedaan antar perlakuan dianalisis dengan Anava dan dilanjutkan dengan LSDT untuk mengetahui letak perbedaan. Hasil yang diperoleh menunjukkan bahwa pakan lemak tinggi menurunkan kadar HDL, konsentrasi apoprotein A, fungsi endotelium aorta dan arteria koronaria, serta meningkatkan kadar kolesterol total, kadar LDL dan konsentrasi apoprotein B. Chitosan meningkatkan kadar HDL dan konsentrasi apoprotein A, serta menurunkan kadar kolesterol total, kadar LDL dan konsentrasi apoprotein B tikus dengan diet lemak tinggi. Pakan lemak tinggi meningkatkan tebal dinding arteria koronaria dan chitosan dapat menurunkan tebal dinding arteria koronaria setelah perlakuan dengan pakan lemak tinggi. Pakan lemak tinggi + chitosan yang diberikan secara simultan dapat meningkatkan diameter lumen arteria koronaria. Semua penelitian tersebut secara signifikan (P<0,05). Baik pakan lemak tinggi maupun pakan lemak tinggi + chitosan yang diberikan setelah satu bulan perlakuan lemak tinggi tidak signifikan menurunkan diameter lumen arteria koronaria. Secara histopatologik, aorta dan arteria koronaria tikus yang diberi pakan normal (K) menunjukkan gambaran normal, sedangkan aorta dengan pakan lemak tinggi (P1) menunjukkan adanya plak ateroma. Tikus dengan pakan lemak tinggi + chitosan secara simultan (P2), gambaran struktur aorta dan arteria koronaria normal, sedangkan kelompok tikus yang diberi chitosan sebulan setelah makan lemak tinggi (P3), juga mempunyai gambaran normal, namun ada beberapa aorta mempunyai gambaran plak ateroma. Analisis imunohistokimia menggunakan antibodi anti C-Reactive Protein terhadap ekspresi CRP aorta adalah negatif untuk semua kelompok. Ekspresi CRP arteria koronaria tikus putih yang diberi pakan normal (K) adalah negatif, sedangkan yang diberi pakan lemak tinggi (P1) positif. Ekspresi CRP arteria koronaria tikus dengan pakan lemak tinggi dan diberi chitosan (P2) tetap negatif, tetapi pemberian chitosan setelah 1 bulan (P3) positif. Jadi dari keseluruhan hasil dapat dikatakan bahwa: 1. Pakan lemak tinggi berpengaruh menurunkan kadar HDL, konsentrasi apoprotein A, fungsi endotelium aorta dan arteria koronaria; serta meningkatkan kadar kolesterol total, kadar LDL dan konsentrasi apoprotein B. 2. Chitosan berpengaruh meningkatkan kadar HDL dan konsentrasi apoprotein A; serta menurunkan kadar kolesterol total, kadar LDL dan konsentrasi apoprotein B tikus putih dengan diet lemak tinggi. 3. Chitosan berpengaruh mempertahankan fungsi endotelium aorta tikus putih diet lemak tinggi. 4. Ekspresi CRP aorta negatif. Ekspresi CRP arteria koronaria negatif untuk perlakuan pakan normal dan diet lemak tinggi + chitosan secara simultan, sedangkan perlakuan dengan pemberian chitosan setelah satu bulan tampak positif. Berdasarkan hasil penelitian ini, dapat disimpulkan, bahwa pakan lemak tinggi adalah faktor utama penyebab aterosklerosis, CRP beraksi dalam kejadian awal terjadinya aterosklerosis, chitosan 180 mg/ kg BB/ hari efektif mencegah terjadinya plak ateroma.
Atherosclerosis, the most common cause of death in developing country is a complex process involving the interplay of genetic and environmental factors and the involvement of multiple cell types. Injury to the vascular endothelium is thought to iniate the atherosclerotic lesion. The objective of this study was to analyze the influences of chitosan on lipoprotein profile, endothelial function of aorta, endothelial function of coronary artery, and C-Reactive Protein in rats by high fat induction. Twenty male Sprague Dawley rats, 1,5 months of age were used as experimental animals. All rats were adapted in 20 single cages for 7 days and given basal diet containing normal fat and water ad libitum. The rats were divided into 4 groups of 5. Group I was fed basal diet containing normal fat for 3 months. Group II, III and IV was fed high fat diet. Group II was used as a control (no treatment). Group III was fed chitosan 180 mg kg BW per day. Group IV was given chitosan using the same doses as group III, one month after feeding high fat diet. Chitosan was given orally in 2 ml aquadest. After 90 days, each rat was fast for 12-14 hours before blood collected. Blood was collected from the orbital vein for lipoprotein profile analysis. The rats were then sacrificed and the heart including aorta were collected for histopathological and immunohistochemical (expression of CRP) analysis. The difference between treatment was statistically analyze by Anava, and continued by LSDT to locate the difference. The result showed that high fat diet decreased HDL level, apoprotein A concentration, endothelial function of aorta and coronary artery, but increased total cholesterol level, LDL level and apoprotein B concentration. Chitosan increased HDL level and apoprotein A concentration, but decreased total cholesterol level, LDL level and apoprotein B concentration in rats by high fat induction. High fat diet increased coronary artery wall thickness and chitosan could be decreased coronary artery in rats. High fat diet + chitosan that given simultaneously could be increased coronary artery lumen diameter in rats. All those results were statistically significant (P<0,05). High fat diet did not significantly decreased coronary artery lumen diameter, as well as the rats that given chitosan after one month. Histopatologic analysis of aorta and coronary artery of rats that given normal diet showed that there was no atherosclerotic lesions, whereas aorta in rats fed high fat diet (P1) showed atheroma plaques. Structural illustration of aorta and coronary artery in rats fed high fat diet + chitosan (P2) did not show atherosclerotic lesions, whereas the group of rats that given chitosan after 1 month (P3), also did not show atherosclerotic lesions, in spite of several of aortas were atheroma plaques illustration. Immunohistochemistry analysis using antibody anti CRP of aortas showed that expression of CRP negative for all groups. CRP expression of coronary artery of rats that given normal diet (K) were negative, whereas rats that given high fat diet (P1) and no treatment were positive. CRP expression of coronary artery for rats that given high fat diet and given chitosan (P2) were negative, but rats that given chitosan after one month (P3) were positive. The overall results can be said that: 1. High fat diet decreased HDL level, apoprotein A concentration, endothelial function of aorta and coronary artery; and also increased total cholesterol level, LDL level and apoprotein B concentration. 2. Chitosan increased HDL level and apoprotein A concentration; and also decreased total cholesterol level, LDL level and apoprotein B concentration in rats by high fat induction. 3. Chitosan was able to prevent endothelial function of aorta in rats by high fat induction. 4. CRP expression of aortas were negative. CRP expression of coronary arteries were negative of rats that given normal diet and rats that given high fat diet and given chitosan simultaneously, whereas rats that given chitosan after one month were visible positive. Based on the research result could be concluded that: High fat diet was the most common caused of atherosclerosis, CRP may involve in atherosclerosis and chitosan 180 mg kg BW per day was effective for preventing the formation of atheroma plaque.
Kata Kunci : Aterosklerosis, chitosan, ekspresi CRP, endotelium, pakan lemak tinggi.
