Efek Penambahan Asam Rosmarinat pada Tikus Diabetes yang Diberikan Telmisartan terhadap Penurunan Ekspresi NF-kβ Glomerulus

Abstract

Pendahuluan. Nefropati diabetik merupakan komplikasi diabetes yang sering terjadi, salah satunya akibat peningkatan radikal bebas melalui akivasi NF-kβ serta Angiotensin II. Asam rosmarinat bermanfaat sebagai antioksidan dan antiinflamasi, sedangkan telmisartan merupakan agonis parsial PPAR-γ yang memiliki efek antifibrotik. Penelitian ini dilakukan untuk mengidentifikasi efek asam rosmarinat dan telmisartan terhadap penurunan ekspresi subunit p65 NF-kB pada glomerulus tikus diabetes. Metode. Penelitian eksperimental laboratorik, post-test only controlled group menggunakan tikus Rattus norvegicus yang terbagi menjadi kelompok kontrol negatif, kontrol positif, asam rosmarinat 75 mg/kg/hari, telmisartan 1 mg/kg/hari, serta kombinasi asam rosmarinat 75 mg/kg/hari dan telmisartan 1 mg/kg/hari setiap hari yang dibedah pada minggu ke-8 setelah tikus menjadi diabetes. Gula darah lebih dari 270 mg/dL menunjukkan telah terjadi diabetes pada tikus. Pengukuran albuminuria dengan metode ELISA dan ekspresi subunit p65 NF-kβ dengan metode imunofluorosensi. Hasil . Didapatkan rerata ekspresi subunit p65 NF-kβ pada kontrol negatif 519,70 (simpang baku [SB] 158,12) arbitrary unit , kontrol positif 702,19 (SB 189,69) arbitrary unit , kelompok asam rosmarinat 631,19 (SB 119,21) arbitrary unit , kelompok telmisartan 355,68 (SB 44,71) arbitrary unit , kombinasi asam rosmarinat dan telmisartan 572,37 (SB 98,09) arbitrary unit dengan p<0,001.  Uji p ost hoc test menunjukkan perbedaan rerata ekspresi subunit p65 NF-kβ yang signifikan antara kontrol positif dengan kelompok telmisartan (p<0,001). Namun, tidak didapatkan perbedaan rerata ekspresi subunit p65 NF-kβ yang signifikan antara kontrol positif dengan asam rosmarinat (p=1,000) maupun dengan kombinasi asam rosmarinat dan telmisartan. Simpulan. Didapatkan penurunan ekspresi subunit p65 NF-kB pada kelompok telmisartan, namun penambahan asam rosmarinat pada tikus diabetes yang diberikan telmisartan tidak dapat menurunkan ekspresi subunit p65 NF-kB pada level setara dengan kontrol negatif. Kata Kunci : Asam rosmarinat, ekspresi subunit p65 NF-kB, nefropati diabetik, telmisartan The Additive Effect of Rosmarinic Acid for The Reduction of Glomerular NF-kB Expression in Diabetes Rat that was given Telmisartan Introduction. Diabetic nephropathy is one of the common complications of diabetes, which one of its causes is the increase of free radicals through the activation of NF-kβ and Angiotensin II. Rosmarinic acid has the activity as the anti-oxidant and anti-inflammatory, and the telmisartan is the partial PPAR-γ agonist that has the anti-fibrotic effect. This study aimed to identify the effect of rosmarinic acid and telmisartan in the reduction of subunit p65 NF-kB expression on the glomerular diabetes rat. Methods . An experimental study with a post-test only controlled group was conducted in a group of rats (Rattus norvegicus). Rats were randomly divided into five groups (n=3-4 per group): three treatment groups (group 1: rosmarinic acid 75 mg/kg/day; group 2: telmisartan 1 mg/kg/day, group 3:  combination of rosmarinic acid 75 mg/kg/day and telmisartan 1mg/kg/day per day), and two control groups (negative and positive control group). After eight weeks, rats were dissected. Blood sugar more than 270 mg/dl confirmed that the rats in diabetes state. The measurement of albuminuria was done using ELISA and the expression of subunit p65 NF-kβ using the immunofluorescence method. Results. The expression of subunit p65 NF-kβ in negative control group was 519.70 (SD 158.12), 702.19 (SD 189.69) in positive control group, 631.19 (SD 119.21) in the rosmarinic acid group, 355.68 (SD 44.71) in the telmisartan group, and 572.37 (SD 98.09) in the combination group (p<0.001). The post hoc test showed that the mean value of subunit p65 NF-kβ expression was significantly different between the positive control group and the telmisartan group (p<0.001). But, there was no significant mean difference of subunit p65 NF-kβ expression between the positive control group and the rosmarinic acid group (p=1.000), as well as between the combination rosmarinic acid and telmisartan group. Conclusion. The addition of telmisartan can reduce expression of the subunit p65 NF-kB. However, adding the rosmarinic acid in diabetes rats given telmisartan did not reduce the expression of subunit p65 NF-kB in the same level with the negative control group.