| Sažetak | Šećernu bolest (diabetes mellitus, DM) karakterizira poremećaj metabolizma ugljikohidrata, masti i proteina, a uzrokovana je smanjenim lučenjem ili smanjenom osjetljivošću tkiva na inzulin. Dijabetes tipa 1 (T1D) se odnosi na 5-10% svih slučajeva dijabetesa i obično se javlja u ranijoj životnoj dobi dok je tip 2 (T2D) prisutan u većini slučajeva i to u kasnijoj životnoj dobi. T1D je upalna autoimuna bolest u kojoj -stanice gušterače selektivno uništavaju stanice imunološkog sustava (hipoinsulinemija i hiperglikemija). T2D je povezana s pretilošću i metaboličkim sindromom. Inzulin je nadomjestna konvencionalna terapija u liječenju T1D, ali zbog nuspojava ove terapije je porastao interes za alternativnu fitoterapiju. U terapiji T2D koristi se više vrsta lijekova koji pokrivaju različite mehanizame djelovanja. Obećavajuće rezultate su pokazali bioaktivni fenolni spojevi koji mogu djelovati antioksidacijski, protuupalno, hipoglikemično i hipokolesterolemično. Prednosti mediteranskog stila života (maslina i njeni proizvodi) su poznate stoljećima i korištene u sprječavanje i liječenje različitih metaboličkih sindroma.
U ovom istraživanju sam pratila sastav masnih kiselina u jetri dijabetičnih (T1D) i dijabetičnih/pretilih (T2D) štakora te učinak polifenola lišća masline na sastav masnih kiselina jetre u dijabetičnih (T1D) štakora. T1D je izazvan injiciranjem (i.p.) streptozotocina (SZT), a pretilost/T2D je izazvana visoko-masnom hranom (HFD). Dijabetički štakori (T1D) su tretirani ekstraktom lišća masline (512, 768 i 1024 mg/kg) te inzulinom. Sastav masnih kiselina (FAME) određen je u homogenatu jetre korištenjem plinske kromatografije. Statistička analiza provedena je Mann-Whitney U-testom i Kruskal-Walis testom primjenom programa Statistica.
Značajne razlike masnih kiselina i omjera su pronađene u dijabetičnih štakora (T1D) u odnosu na kontrolnu skupinu (16:1, 18:2, 20:2, 20:4, 20:5, 24:0, 22:6, n-6, n-3, n-6/n-3, desaturaza delta-5 (D5D), 16:1/16:0, 16:1/18:1, 20:4/22:6, 18:2/20:4). Terapija ekstraktom polifenola maslinova lišća značajno mijenja razine 16:0, 16:1, 18:0, 18:1, 18:2, 18:3, 20:2, 20:3, 20:4, 24:0, n-3 jednostruko-nezasićenih (MUFA) masnih kiselina, omjera 18:2/20:4, 16:1/16:0, 16:0/18:0, 16:1/18:1 i n-6/n-3 te stearoil-CoA desaturaze 1 (SCD1) i elongaze 6 (Elovl6) u jetri dijabetičnih štakora. Terapija inzulinom značajno mijenja razinu 16:0, 16:1, 18:2, 20:1, 20:2, 20:3, 24:0, 22:5, n-6 i n-3 masnih kiselina, omjera 18:2/20:4, 16:1/16:0, 16:0/18:0, 16:1/18:1 i n-6/n-3 te Elovl6 i D5D u jetri dijabetičnih štakora. Zabilježena je značajna razlika u razini 16:1, 18:3, 20:4, 24:0, 22:5, 22:6, n-6, n-3 i višestruko-nezasićenih (PUFA) masnih kiselina, omjera 16:1/16:0, 16:1/18:1, 20:4/22:6, n-6/n-3 i PUFA/SFA te desaturaza delta-6 (D6D) u jetri dijabetičnih štakora sa T1D i T2D.
Iz navedenog se može zaključiti da dijabetes tipa 1 i 2 mijenjaju metabolizam masnih kiselina u jetri štakora. Pronađene su značajne razlike u metabolizma masnih kiselina u tipu 1 i 2 dijabetesa. U odnosu na terapiju inzulinom, terapija polifenolima lišća masline značajno mijenja razinu n-6 i MUFA te ključne enzime u metabolizmu masnih kiselina, SCD1 i D6D. |
| Sažetak (engleski) | Diabetes mellitus (DM) is characterized by a disorder of carbohydrate, fat, and protein metabolism, caused by decreased secretion or reduced tissue sensitivity to insulin. Type 1 diabetes (T1D) refers to 5-10% of all cases of diabetes and usually occurs at an earlier age, while type 2 (T2D) is present in most cases in later life. T1D is an inflammatory autoimmune disease in which β-cells pancreas destroys the immune system cells (hypoinsulinemia and hyperglycemia). T2D is associated with obesity and metabolic syndrome. Insulin is a replacement therapy for T1D, but due to the side effects associated with insulin therapy, there is an increasing interest in alternative therapy especially phytotherapy. In T2D therapy, several types of drugs are used with different mechanisms of action. Bioactive phenolic compounds are a wide-beneficial therapy that can act as antioxidant, anti-inflammatory, hypoglycemic and hypocholesterolemic. The benefits of the Mediterranean lifestyle (olives and its products) have been known a long time and used in prevention and treatment of various metabolic disorders including diabetes. In this study, the effect of treatment with olive leaf polyphenols on the profile of hepatic fatty acids in diabetic/obese rats was studied. T1D was induced intraperitoneally with streptozotocin (SZT, i.p.), and obesity/T2D was caused by consumption of high-fat (HFD). Diabetic rats were treated with leaf leaves extract (512, 768 and 1024 mg/kg) and insulin. The composition of individual fatty acids (FAME) was determined in liver homogenate using gas chromatographic analysis. Statistical analysis was carried out by Mann-Whitney and Kruskal-Wallis test using Statistical Program.
Significant differences in fatty acids and ratios were found in diabetic rats compared to the control group (16: 1, 18: 2, 20: 2, 20: 4, 20: 5, 24: 0, 22: 6, n-6, n -3, n-6 / n-3, delta-5 (D5D), 16: 1/16: 0, 16: 1/18: 1, 20: 4/22: 6, 18: 2/20: 4 ). The therapy with olive leaves polyphenols changed significantly 16: 0, 16: 1, 18: 0, 18: 1, 18: 2, 18: 3, 20: 2, 20: 3, 20: 4, 24: 0, n- 3, mono-unsaturated (MUFA) fatty acids, ratios 18: 2/20: 4, 16: 1/16: 0, 16: 0/18: 0, 16: 1/18: 1 and n-6 / n-3 as well as stearoyl-CoA desaturase 1 (SCD1) and elongase 6 (Elovl6) in the liver of diabetic rats. Insulin therapy changed significantly the 16: 0, 16: 1, 18: 2, 20: 1, 20: 2, 20: 3, 24: 0, 22: 5, n-6 fatty acids, n- 2/20: 4, 16: 1/16: 0, 16: 0/18: 0, 16: 1/18: 1, n-6 / n-3 ratios, and Elovl6 and D5D in liver diabetic rats. Also, a significant difference was found in 16: 1, 18: 3, 20: 4, 24: 0, 22: 5, 22: 6, n-6, n-3 and polyunsaturated fatty acids (PUFA), ratios of 16:1/16: 0, 16: 1/18: 1, 20: 4/22: 6, n-6 / n-3 and PUFA / SFA as well as delta-6-desaturase (D6D) in T1D and T2D rat liver.
It can be concluded from these results that type 1 and 2 diabetes alter the fatty acid metabolism in the rat liver. Significant differences in fatty acid metabolism in type 1 and 2 diabetes were found. In comparison to insulin therapy, therapy with olive leaf polyphenols significantly changed the level of n-6 and MUFA and key enzymes in fatty acid metabolism, SCD1, and D6D. |
