Toxicity to sea urchin egg development of the quinone fraction obtained from Auxemma oncocalyx

Abstract

Auxemma oncocalyx Taub. belongs to the Boraginaceae family and is native to the Brazilian northeast where it is known as "pau-branco". We investigated the ability of the water soluble fraction isolated from the heartwood of A. oncocalyx to inhibit sea urchin egg development. This fraction contains about 80% oncocalyxone A (quinone fraction), a compound known to possess strong cytotoxic and antitumor activities. In fact, the quinone fraction inhibited cleavage in a dose-dependent manner .2) µg/ml, N = 6], and destroyed the embryos in the blastula stage [IC 50 of 16.2 (13.7-19.2) µg/ml, N = 6]. We suggest that this activity is due to the presence of oncocalyxone A. In fact, these quinones present in A. oncocalyx extract have strong toxicity related to their antimitotic activity.

Toxicity effect of Auxemma oncocalyx fraction and its active principle oncocalyxone A on in vitro culture of caprine secondary follicles and in vitro oocyte maturation

“…It is known that DXR can induce cellular apoptosis. Moreover, a study evaluating different concentrations (1 to 100 µg/mL) of a quinone fraction of A. oncocalyx (containing 80% of onco A) in sea urchin eggs reported that the cleavage of eggs was inhibited in a concentration-Toxicity effect of Auxemma oncocalyx fraction and its active principle oncocalyxone A on in vitro culture of caprine... dependent manner, and, when a concentration of 30 µg/mL was used, it caused total destruction (100%) of the embryos (COSTA-LOTUFO et al, 2002).…”

“…Some studies have attributed biological activities such as analgesic, anti-oxidant, anti-tumor, and antiinflammatory effects to this plant (PESSOA et al, 1992;LINO et al, 1996;FERREIRA et al, 2003FERREIRA et al, , 2004. Oncocalyxone A (onco A) isolated from the stem heartwood of the plant has demonstrated high antioxidant activity (FERREIRA et al, 2003) and an antiproliferative effects on tumor cell cultures (COSTA-LOTUFO et al, 2002).…”

Fraction of <b><i>Auxemma oncocalyx</i></b> and Oncocalyxone A Affects the In Vitro Survival and Development of Caprine Preantral Follicles Enclosed in Ovarian Cortical Tissue

“…In a study testing different concentrations (1-100 g/ml) of a quinone fraction of A. oncocalyx (containing 80% of onco A) in sea urchin eggs, it was found that the cleavage of eggs was inhibited in a concentration-dependent manner. The early destruction of embryos at the blastula stage occurred when a concentration of 10 g/ml was used, and total destruction (100%) of the embryos occurred at a concentration of 30 g/ml, associated with a rupture of the embryo membranes [22]. The cytotoxicity of onco A was also observed when applied to human tumor cell lines [15,16,23] and normal skin fibroblasts [23], at concentrations varying from 0.4 to 25 g/ml.…”

“…Several studies [14,15,16,22,23] have already shown in vitro cytotoxic effects of the quinone fraction of A. oncocalyx , represented mainly by onco A. However, Ferreira et al [9] showed an antioxidant effect of the fraction of A. oncocalyx on mice in vivo.…”

Anti-mitotic activity towards sea urchin eggs of dichloromethane fraction obtained from Allamanda schottii Pohl (Apocynaceae)

“…Also, this model has been utilized to detect the cytotoxic and teratogenic activities of new compounds (Morale et al, 1998;Costa-Lotufo et al, 2002b;Hansen et al, 2003;Jimenez et al, 2003). Recently, some works have emphasized the study of alterations in sea urchin egg development as a multicellular model for evaluating anti-tumor activity (Costa-Lotufo et al, 2002a;CostaLotufo et al, 2003;Knudson, 2004; Costa-Lotufo et al, Louisa M. A. Sousa, Rubens L. Monte Neto, Dionezine F. Navarro Schmidt, Márcia R. Oliveira 2005).…”