Olive leaf powder prevents nonalcoholic steatohepatitis in Sprague–Dawley rats fed a high-fat and high-cholesterol diet oleh Katsuhisa Omagari, Chiaki Koba, Asuka Nagata, Linh Chi Thi Ngo, Mayu Yamasaki, Ayumi Fukuda, Masahiro Yuasa, Kazuhito Suruga, Nobutada Inada, Mayuko Ichimura-Shimizu, Koichi Tsuneyama