Efek Ekstrak Metanol Hibiscus sabdariffa Linn. terhadap Indeks Hipertrofi, Kadar Brain-Type Natriuretic Peptide (BNP) Dan Pparγ Co-Activator-1α (PGC-1α) pada Jantung Tikus dengan Overtraining = Effect Methanolic Extract of Hibiscus Sabdariffa Linn. on Hypertrophy Index, Brain-Type Natriuretic Peptide (BNP) and Ppariγ Co-Activator-1α (PGC-1α) Level in Overtrained Rat Heart.