We have previously described the anti-allergic activities of a pooled fraction of tetranortriterpenoids (TNTPs) containing 6α-acetoxygedunin, 7-deacetoxy-7-oxogedunin, andirobin and methyl angolensate isolated from the seeds of Carapa guianensis. In the present study, we performed in vitro studies in order to elucidate the mechanisms by which TNTPs present their anti-allergic effects and to identify the bioactive compound(s) present in such fraction. Here, we show that in vitro incubation of eosinophils with the pooled TNTP fraction, as well as with each one of the five isolated tetranortriterpenoids, impaired the adhesion of eosinophils to tumor necrosis factor-α (TNF-α)-primed tEND.1 endothelial cells. Furthermore, the individual or pooled TNTPs impaired CCL11/eotaxin-mediated chemotaxis. By contrast, pooled TNTPs failed to inhibit adhesion and chemotaxis of T lymphocytes. However, TNTPs were able to impair anti-CD3 monoclonal antibody-induced T cell proliferation and the expression of CD25 and CD69. These data suggest that TNTPs prevent T cell activation. Pretreatment of splenocytes with the pooled TNTP fraction, as well as with each one of the five isolated TNTPs, inhibited ovalbumin (OVA)-induced in vitro production of interleukin-2, chemokine (C-C motif) ligand 11 (CCL11) and regulated on activation normal T cell expressed and secreted (RANTES, also known as CCL5). TNTPs (except 6α-acetoxygedunin) also impaired nuclear factor-κB (NFκB) nuclear translocation in OVA-challenged splenocytes. Taken together, these results demonstrate that the anti-allergic effects of TNTPs isolated from C. guianensis might rely on their ability to inhibit eosinophil migration, as well as the activation of T lymphocytes, which is shared by the five isolated TNTPs.
The crude latex of Crown-of-Thorns (Euphorbia milii var. hislopii) is a potent plant molluscicide and a promising alternative to the synthetic molluscicides used in schistosomiasis control. The present study was undertaken to investigate the embryofeto-toxic potential of E. milii latex. The study is part of a comprehensive safety evaluation of this plant molluscicide. Lyophilized latex (0, 125, 250 and 500 mg/kg body weight) in corn oil was given by gavage to Wistar rats (N = 100) from days 6 to 15 of pregnancy and cesarean sections were performed on day 21 of pregnancy. The numbers of implantation sites, living and dead fetuses, resorptions and corpora lutea were recorded. Fetuses were weighed, examined for external malformations, and fixed for visceral examination, or cleared and stained with Alizarin red S for skeleton evaluation. A reduction of body weight minus uterine weight at term indicated that E. milii latex was maternally toxic over the dose range tested. No latex-induced embryolethality was noted at the lowest dose (125 mg/kg) but the resorption rate was markedly increased at 250 mg/kg (62.5%) and 500 mg/kg (93.4%). A higher frequency of fetuses showing signs of delayed ossification (control: 17.4%; 125 mg/kg: 27.4% and 250 mg/kg: 62.8%; P < 0.05 vs control) indicated that fetal growth was retarded at doses > or = 125 mg latex/kg body weight. No increase in the proportion of fetuses with skeletal anomalies was observed at the lowest dose but the incidence of minor skeletal malformations was higher at 250 mg/kg body weight (control: 13.7%; 125 mg/kg: 14.8%; 250 mg/kg: 45.7%; P < 0.05 vs control). Since a higher frequency of minor malformations was noted only at very high doses of latex which are embryolethal and maternally toxic, it is reasonable to conclude that this plant molluscicide poses no teratogenic hazard or, at least, that this possibility is of a considerably low order of magnitude.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.