Polyphenols from the extracts of Areca catechu L. and Quercus infectoria Oliv. inhibited phospholipase A(2), proteases, hyaluronidase and L-amino acid oxidase of Naja naja kaouthia Lesson (NK) and Calloselasma rhodostoma Kuhl (CR) venoms by in vitro tests. Both extracts inhibited the hemorrhagic