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"Pendahuluan: Penelitian dilakukan untuk mengetahui peran senyawa flavonoid mangiferin dalam meningkatkan ekspresi mRNA HIF-1α dan sebagai pencekal besi dalam menstabilkan HIF-1α pada lini sel HepG2 dan menganalisis interaksi mangiferin dengan prolil hidroksilase (PHD2) secara simulasi docking.Metode: Sel HepG2 dikultur hingga >80% konfluen dan selanjutnya diberikan mangiferin konsentrasi 25-200μM. Kuersetin digunakan sebagai pembanding flavonoid mangiferin yang bekerja di dalam inti sel, sedangkan DFO dan CuCl2 digunakan sebagai pembanding daya ikat terhadap besi. Ekspresi mRNA HIF-1α ditentukan dengan real time RT- PCR/q-PCR, dan stabilisasi protein HIF-1α ditentukan mengunakan teknik ELISA. Simulasi docking dilakukan terhadap protein PHD2 dengan mangiferin, CuCl2, deferoksamin (DFO), dan campuran mangiferin+ kuersetin.Hasil: Uji viabilitas sel menggunakan metode MTS dengan pemberian mangiferin, kuersetin, campuran mangiferin-kuersetin, DFO dan CuCl2 (25-200μM) memperlihatkan hasil diatas 85%. Ekspresi mRNA HIF-1α dengan mangiferin, kuersetin, mangiferin+kuersetin, dan DFO menunjukkan hasil sedikit lebih tinggi dibanding kontrol. Konsentrasi protein HIF-1α pada pemberian mangiferin, kuersetin, mangiferin-kuersetin, DFO dan CuCl2 lebih tinggi dibanding kontrol. Simulasi docking mangiferin terhadap PHD2 memperlihatkan ΔG= -16,22, dan DFO menunjukkan ΔG= -17,15. Terdapat interaksi antara mangiferin, dan DFO dengan besi dan asam amino pada situs katalitik domain PHD2, sedangkan CuCl2 tidak berinteraksi dengan residu asam amino pada domain PHD2, tetapi langsung menggantikan Fe. Efek penghambatan terhadap PHD2 oleh mangiferin dan kuersetin disebabkan oleh delokalisasi elektron melalui kompleks transfer elektron.Kesimpulan: Mangiferin dapat meningkatkan ekspresi mRNA HIF-1α dan meningkatkan protein HIF-1α, menurun protein PHD2 dan menurunkan protein HO-HIF-1α pada lini sel HepG2 secara in vitro. Analisis docking terdapat interaksi antara mangiferin, dan DFO dengan besi dan asam amino PHD2. Mangiferin memiliki stabilitas pengkikatan dengan besi yang berdekatan dengan DFO.

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Introduction: This research was conducted to determine the role of flavanoid mangiferin to increase expression HIF-1α mRNA, and as an iron chelator to stabilize protein HIF-1α in cell line HepG2 and analyzes the interaction of mangiferin with prolil hidroksilase (PHD2) by docking simulation.

Methods: HepG2 cells were cultured and treated by mangiferin with concentration between 25-200μM. Quercetin is used as a comparison mangiferin flavonoid that works in the nucleus and DFO, CuCl2 is used as a comparison to iron-binding. HIF- 1α mRNA expression was determined by real time RT-PCR/q-PCR, and the stability HIF-1α protein were measured by the increase in HIF-1α protein, decreased PHD2 protein and decreased HO-HIF-1α using ELISA. Docking simulation was conducted between PHD2 protein and mangiferin, CuCl2, desferoxamine (DFO), and quercetin.

Results: Cell viability with MTS assay showed that cell exposure with 25μM-200μM concentrations of mangiferin, quercetin, mangiferin+quercetin mixture, DFO, and CuCl2 is above 85%. HIF-1α mRNA expression was slightly higher than in controls with mangiferin, quercetin, mangiferin quercetin mixture and DFO. HIF-1α protein concentration and ratios vs untreated controls were above 1 with mangiferin, quercetin, mangiferin quercetin mixture, DFO, and CuCl2. Docking simulation mangiferin with PHD2 showed ΔG= -16,22. Docking simulation with DFO showed ΔG= -17,15, and interact mangiferin, and DFO with iron in the catalytic site of PHD2 and with amino acid residues, whereas CuCl2 does not react with amino acid residues in the PHD2 domain, but directly replaces Fe. The inhibitory effect to PHD2 by mangiferin and quercetin is considered by electron delocalisation through an electron transfer complex.

Conclusion: Mangiferin can increase HIF-1α mRNA expression and HIF-1α protein levels in HepG2 cell line by in vitro. Binding interaction with iron and PHD2 amino acids occurs by mangiferin and DFO. Mangiferin has stability iron binding a similar with DFO."

"Penelitian ini bertujuan menganalisis ekspresi HIF-1? pada hati tikus yang diracuni CCl4 dalam kondisi normoksia, dengan atau tanpa perlindungan N-asetil sistein (NAC). Sebanyak 25 ekor tikus Sprague-Dawley jantan dibagi menjadi 5 grup: kontrol, diberikan minyak kelapa, diberikan CCl4, disuntik NAC lalu diberikan CCl4, diberikan CCl4 lalu disuntik NAC. Ekspresi mRNA HIF-1? dianalisis dengan real time RT-PCR dan dikuantifikasi menggunakan metode Livak. Ekspresi protein HIF-1? diukur menggunakan ELISA. Hasil ekspresi mRNA dan protein HIF-1? tertinggi terdapat pada grup tikus yang hanya diberi CCl4, lalu lebih rendah pada grup yang diberi NAC sebelum CCl4, grup yang diberi NAC setelah CCl4, grup kontrol, dan grup yang diberi minyak kelapa. Disimpulkan bahwa pemberian CCl4 pada kondisi normoksia menyebabkan peningkatan ekspresi HIF-1?, sedangkan pemberian NAC terbukti menurunkan ekspresi HIF-1a. Hal tersebut menunjukkan bahwa mekanisme perubahan ekspresi pada HIF-1a memang dipengaruhi oleh radikal bebas yang terbentuk akibat metabolisme CCl4.

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This study analyzed the expression of HIF-1? in liver rat tissue induced by CCl4 under normoxic conditions, with or without N-acetyl cysteine (NAC) protection. Twenty five male Sprague-Dawley rats were divided into 5 group: control rats, rats administered with coconut oil, rats administered with CCl4, rats injected with NAC then administered with CCl4, rats administered with CCl4 then injected with NAC. The expression of HIF-1? mRNA was measured by real time RT-PCR using Livak method, while the HIF-1? protein was measured by ELISA assay. Results showed that the highest HIF-1? mRNA and protein expression were found in the group treated by CCl4 and then was gradually lowered in the pre-NAC group, post-NAC group, control group, and coconut oil group. The overall result of this study show the effect of CCl4-treated rats under normoxic conditions increased the expression of HIF-1?, while NAC treatment decreased the expression of HIF-1?. These findings show that free radical formed by CCl4 metabolism play a role in the regulation of HIF-1"