ABSTRAKEffervescent rosela ungu merupakan salah satu bentuk diversifikasi pangan lokal yang tinggi antioksidan. Antioksidan memiliki efek mencegah reaksi oksidasi sehingga tidak sampai terjadi stres oksidatif. Tujuan penelitian ini yaitu untuk mengetahui efek antioksidan effervescent rosella ungu dalam mencegah penurunan SOD dan mencegah kerusakan sel hepar tikus wistar. Penelitian ini disusun menggunakan Post-test Only Control Group Design dengan Rancangan Acak lengkap (RAL), menggunakan tikus wistar jantan sebanyak 16 ekor dan lama perlakuan selama 4 minggu. Terdapat 4 kelompok, kontrol negatif (pakan standar + 3ml aquadest), kontrol positif (pakan standar + minyak jelantah 1ml 118mek/kg + 2ml aquadest), perlakuan dosis I (pakan standar + minyak jelantah 1ml 118mek/kg + effervescent rosela ungu 3g/2ml), dan perlakuan dosis II (pakan standar + minyak jelantah 1ml 118mek/kg + effervescent rosella ungu 6 g/2 ml). Hasil pengamatan dianalisa dengan ANOVA dan dilanjutkan uji BNT dengan taraf 5%. Hasil penelitian menunjukkan perlakuan uji in vivo berpengaruh nyata (α=0,05) terhadap nilai SOD serum. Pengamatan sel hepar tikus wistar secara histopatologi menunjukkan kelompok perlakuan dosis I maupun dosis II mampu mencegah terjadinya stres oksidatif dengan indikasi sangat sedikit sel hepar yang mengalami nekrosis. ABSTRACTPurple rosella effervescent is one diversification forms tioxidant has an effect to prevent oxidation reaction, thus it can prevent oxidative stress. The objective of this research is to find out antioxidant effect of purple rosella effervescent in preventing the decrease of SOD value and in preventing the damage of hepar's cell of wistar. This research was composed by using Post-test Only Control Group Design with Complete Randomized Design, using 16 male wistar rats, and 4 week treatment time. There were 4 groups, namely negative control (standard food + 3ml distilled water), positive control (standard food + 1ml 118mek/kg waste cooking oil + 2ml distilled water), dose I treatment (standard food + 1ml 118mek/kg waste cooking oil + 3g/2ml purple rosella effervescent), and dose II treatment (standard food + 1ml 118mek/kg waste cooking oil + 6g/2ml purple rosella effervescent). The result of the observation was analysed by using ANOVA and continued by BNT test with 5% degree. The result shows that the treatment of in vivo test has significant effect (α=0,05) towards SOD serum value. of local food which containing high antioxidant. AnThe histopathologically observation of hepar's cell of wistar shows both treatment groups of dose I and dose II can prevent oxidative stress with little indication of hepar cells experiencing necrosis.