Antinociceptive activity of Calotropis procera latex in mice - Soares, P M; Lima, S R; Matos, S G; Andrade, M M; Patrocínio, M C; de Freitas, C D; Ramos, M V; Criddle, D N; Cardi, B A; Carvalho, K M; Assreuy, A M; Vasconcelos, S M (J Ethnopharmacol, 2005)