ABSTRAK
Gamma oryzanol dalam Rice Bran Oil (RBO) telah diteliti melindungi mukosa denganmenghambat sekresi asam dan bertindak sebagai prekusor pada sintesis prostaglandinsehingga diduga berpotensi sebagai gastroprotektif. Penelitian ini bertujuan untukmendapatkan formulasi mikrokapsul RBO dengan kadar γ-oryzanol tertinggi dan untukmengetahui efek gastroprotektif mikrokapsul RBO pada tikus yang diinduksiindometasin (80 mg/kg bb). Response Surface Metodology (RSM) Box-Behnkendengan 3 faktor digunakan untuk mengoptimasi kondisi pembuatan mikrokapsul.Dilakukan karakterisasi terhadap kadar tertinggi γ-oryzanol, Scanning ElectronMicroscope (SEM), particle size distribution, swelling ratio, efisiensi penjerapan, dandisolusi in vitro. Uji aktivitas gastroprotektif dibagi menjadi 7 kelompok yang diberikanaquades, indometasin (80 mg/kg bb), omeprazole 40 mg/kg bb, mikrokapsul RBO (160mg/200 g bb, 320 mg/200 g bb) dan RBO (0.1 ml/200 g bb; 0.2 ml/200 g bb) secara oralselama 7 hari. Pengamatan dilakukan pada % inhibsi ulkus, derajat keasaman lambung,determinasi mukus serta gambaran histopatologi lambung tikus. Hasil optimasi RSMmenunjukkan formula R 11 memberikan kadar γ-oryzanol paling tinggi denganperbandingan 1,5% natrium alginat:RBO:emulgator (60%:30%:10%) sebesar 0,75%.Hasil SEM menunjukkan permukaan yang berpori dengan distribusi ukuran partikelrata-rata 647,013±41,68 µm. Hasil % swelling ratio tertinggi pada medium HCl sebesar44,43%±1,01 pada menit ke 60 dan pada medium aquades sebesar 191,74%±1,85 padamenit ke 240. Hasil efisiensi penjerapan tertinggi sebesar 2,48% dan hasil uji disolusimenunjukkan jumlah γ-oryzanol yang terdisolusi sebesar 9,56 % pada medium HCl pH1,2 dan 50,65% pada medium dapar fosfat. Hasil uji aktivitas gastroprotektifmenunjukkan pemberian mikrokapsul RBO dan RBO dapat menaikkan % inhbisi ulkussecara signifikan dibandingkan dengan kontrol negatif (p <0.05). Hasil pemeriksaanderajat keasaman lambung menunjukkan mikrokapsul RBO dapat menurunkan derajatkeasaman lambung (1,7919 µek/200 g bb). Hasil determinasi mukus menunjukkanlambung tikus yang diberikan mikrokapsul RBO memiliki ketebalan mukus lebih tinggi(0,89586/g bb) jika dibandingkan dengan kelompok negatif. Analisis lebih lanjut padaevaluasi histopatologi menunjukkan peningkatan proteksi dilihat dari rendahnya edema,erosi hemoragik, kongesti kapiler dan infiltrasi leukosit pada submukosa. Hasilpenelitian menunjukkan bahwa Mikrokapsul RBO berpotensi sebagai gastroprotektifpada tikus yang diinduksi indometasin.

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ABSTRACT
Gamma oryzanol content in Rice Bran Oil (RBO) has been studied to protect gastricmucosa by inhibition of acid secretion that stimulated by histamine receptor and also actas a precursor to prostaglandin synthesis. The objective of this research was to obtainedthe formulation of RBO microcapsules with highest γ-oryzanol content and to evaluatedthe gastroprotective effect of RBO microcapsules on indomethacin-induced gastriculcers in rats. The Response Surface Metodology (RSM) Box-Behnken design on threefactors was used to optimize the microencapsulation conditions. Gamma oryzanolcontent, Scanning Electron Microsope (SEM), particle size distribution, swelling ratio,entrapment efficiency and in vitro dissolution was also characterized. Thegastroprotective study was performed on 7 groups who are administered orally thetreatment of aquadest, indomethacin (80 mg/kg BW), omeprazole (40 mg/kg BW),RBO microcapsules (160 mg/200 g BW and 320 mg/200 g BW) and RBO (0,1 ml/200 gBW and 0,2 ml/200 g BW) for seven days. The effect on % inhibition, gastric content,determination of mucous stomach and histopathological analysis were also evaluated.The optimization result was on formula R 11 by comparison of 1,5% sodiumalginate:RBO:emulgator (60%:30%:10%) was 0,75%. The SEM shown porous surfaceand the average of particle distribution was 647±68 µm. The highest swelling ratio was44,43%±1,01 in HCl medium and 191,74%±1,85 in aquadest. The highest entrapmentefficiency was 2,48% and the in vitro dissolution was 9,56% in simulated gastric fluidand 50,65% in simulated intestine fluid. The gastroprotective result showed that RBOmicrocapsules treatment could significantly reduced ulcer index in indomethacininducedgastric ulcers compared with negative control (p < 0.05). The RBOmicrocapsules can reduce gastric content (1,7919 µek/200 g BW) and also highestdetermination of mucous (0,89586/g BW) compared with negative control. Furtherevaluation on HE revealed higher protection characterized by lower edema,capilercongestion, mild hemorrhagic erosion and lower leucocyte infiltration in submucosa.This research shown that RBO microcapsules have potential to be gastroprotectiveagent by indomethacin-induced gastric ulcers in rats.