Effects of Euphorbia milii latex on mitogen-induced lymphocyte proliferation / Efeito do latex de Euphorbia milii sobre a proliferação de linfócitos induzida por mitogénio

The crude latex of "Crown-of-Thorns" (Euphorbia milii var hislopii, syn E.splendens) is a potent plant molluscicide. For this reason, toxicological studies have been performed to evaluate the health risks posed by its use in schistosomiasis control programs. The present study is part of a more comprehensive immunotoxicological evaluation of this molluscicide. Here, we investigated the effects of E. milii latex on the proliferation of human lymphocytes in vitro. Lyophilized latex of E. milii (0, 0.5, 5, 25 and 50 µg/ml) was incubated with whole blood in the presence of proliferation stimulators, i.e. lectins (phytohemagglutinin, concanavalin A and pokeweed mitogen), as well as with human monoclonal antibody against CD3 and tetanus toxoid. Cell proliferation was measured by ³H-thymidine incorporation, and the effects of latex on mitogen-induced cell proliferation were compared to the effects of 10 ng/ml of 12-O-tetradecanoylphorbol-13-acetate (TPA). Results showed that mitogen-induced cell proliferation was markedly enhanced by E. milii latex. This synergistic effect of latex on mitogen-induced lymphocyte proliferation may be due to the presence of TPA-like phorbol esters and/or to mitogenic plant lectins.

O látexbrutoda "Coroa de Cristo" (Euphorbia miliivarhislopii, syn E.splendens) é um potente moluscicidavegetal. Neste sentido, são necessários estudos toxicológicosque visemavaliar possíveis riscos à saúdeassociados ao uso em larga escala desta espécie em áreas endêmicas para esquistossomose. O presente estudo é parte deuma avaliação mais abrangentesobre o potencial tóxico destemoluscicida. Foram investigados in vitro osefeitos dolátex da E.miliisobre a proliferação delinfócitoshumanos. O látexliofilizado (0; 0,5;5;25 e 50 µg/ml)foi incubado comsangue totalna presençade agentes mitogênicos, tais como lectinas(fitohemaglutinina, concanavalina Ae pokeweed), anticorpomonoclonalhumano anti-CD3etoxóide tetânico. A proliferação celularfoi quantificada atravésincorporaçãode ³H-timidina eos efeitos do látexnaproliferação celular induzida por agentes mitogênicosforam comparados comos efeitos de10 ng/mlde12-O-tetradecanoilforbol-13-acetato (TPA). Os resultados demonstram quea proliferação celular induzida poragentes mitogênicosfoimarcadamenteaumentada na presença do látex daE.milii.Oefeito sinérgico observado pode ser devidoà presença deésteres de forbol, como o TPA, e/oude lectinas com ação mitogênica presentes nesta espécie vegetal.

Potency evaluation of antivenoms in Brazil: the national control laboratory experience between 2000 and 2006.

Envenoming from snakebites is an important public health issue in Brazil. In 2005, 28,597 cases were notified (15 cases/100,000 inhabitants), 87.5% due to Bothrops and 9.2% to Crotalus genus. Antivenoms available in Brazil are liquid preparations containing purified equine Fab'2. Since 1987, the National Institute for Quality Control in Health (INCQS/FIOCRUZ) has been testing all lots prior to batch release. Between 2000 and 2006, 619 lots of antivenoms were tested, comprising 2,513,690 ampoules. The potency assay was performed only for bothropic and crotalic antivenoms (485 lots corresponding to 1,866,726 ampoules) due to the unavailability of the other reference venoms. This paper aims to report the last 7-year activities of INCQS on the quality control, batch release and potency evaluation of antivenoms.

Absence of tumor promoting activity of Euphorbia milii latex on the mouse back skin.

Euphorbia milii (Euphorbiaceae) is a decorative plant used in gardens and living fences. In China, it has also been employed in herbal remedies for hepatitis and abdominal edema. Since E. milii latex--lyophilized or in natura--proved to be a potent plant molluscicide, its toxicity to non-target organisms has been comprehensively studied. Concerns on a possible tumor promoting activity have discouraged its use as a locally-available alternative molluscicide in schistosomiasis control programs. Two in vitro assays (inhibition of metabolic cooperation in V79 cells and Epstein-Barr virus induction in Raji cells) had suggested that E. milii latex contained tumor-promoting substances. This study was undertaken to verify whether the latex acts as a tumor promoter in vivo as well. A single dose of the initiating agent DMBA (400 nmol) was applied on the back skin of male and female DBA/2 mice. Testing for tumor promoting activity began 10 days after initiation. Tetradecanoyl phorbol acetate (TPA) (5 nmol, positive control), lyophilized latex (20, 60 and 200 microg per mouse) or acetone (vehicle control) were applied on mouse back skin twice a week for 20 weeks. In TPA-treated mice, papillomas were firstly noted during the 11th week, and by the 17th week all animals exhibited skin tumors. No tumors developed in mice treated with the solvent alone and in those exposed to latex. Findings from the present study therefore indicated that E. milii crude latex does not act as a tumor promoting agent on the mouse back skin assay.

Levels of organochlorine pesticides in the blood serum of agricultural workers from Rio de Janeiro, Brazil.

Serum levels of organochlorine pesticides (OCP) were measured in agricultural workers from Rio de Janeiro State, Brazil. Blood samples from 26 volunteers (24 males, 02 females, 17-60 years old) were taken in October 1997. OCP residues (op'DDT pp'DDT, pp'DDD, pp'DDE, aldrin, dieldrin, endrin, heptachlor, heptachlor-epoxide, (alpha-, beta- and gamma-hexachlorocyclohexane, and hexachlorobenzene) were analyzed by gas chromatography with an electron capture detector. Tests detected pp'DDE in 16 out of 26 samples, but pp'DDE concentration exceeded 1.4 (microgram/L (i.e. 1.8, 2.4 and 4.4 microgram/L) in only 3 of these. beta-HCH was found in 6 (23.1%) out of 26 samples. In one sample (-HCH did not exceed 1.4 microgram/L, but in the remaining samples concentrations ranged from 1.4 to 5.3 microgram/L. The percentage of positive pp'DDE samples increased from the youngest /= 40 yrs: 100%). A similar trend was found for beta-HCH contamination (/= 40 yrs: 66.7%). Dieldrin was found in only one sample. No other OCP residue was found in the samples. Serum concentrations of OCPs found in this study are comparable to blood levels reported for the non-occupationally exposed population in Brazil and elsewhere.

Embryotoxicity of methanol in well-nourished and malnourished rats.

1. The objective of the present study was to investigate whether maternal protein-energy malnutrition alters methanol-induced embryotoxic effects in rats. 2. On day 0 of pregnancy, dams were assigned at random to one of the following treatment groups: well-nourished methanol (WNM), well-nourished control (WNC), malnourished methanol (MNM) and malnourished control (MNC). Malnourished animals received half of the well-nourished food intake (ca 12 g/day) throughout pregnancy. Methanol was administered by gavage (2.5 g/kg body weight) from gestation day 6 to 15. 3. Rats were weighed on days 0, 6 to 15, and 21 of pregnancy. On day 21 rats were submitted to cesarean section. The number of implantations, living and dead fetuses, resorptions and corpora lutea was recorded. All fetuses were weighed, examined for externally visible malformations, fixed, and examined for skeletal anomalies after clearing and staining with Alizarin Red S. 4. An increased proportion of fetuses with skeletal malformations, particularly cervical extra ribs, was found in the methanol-treated groups (fetuses with skeletal malformations: WNC = 5.6%, WNM = 45.4%, MNC = 3.8%, and MNM = 38.8%). Malnutrition produced fetal growth retardation, but did not cause any increase in the occurrence of gross structural malformations. The methanol-induced increase in the proportion of fetuses with extra ribs was not altered by malnutrition, but methanol potentiated the malnutrition-induced increase in the proportion of fetuses with signs of delayed ossification (WNC = 18.6%, WNM = 25.4%, MNC = 39.7%, and MNM = 78.4%). 5. These findings suggest that methanol-induced gross structural malformations are not affected by maternal malnutrition, but the delay in ossification caused by malnutrition is aggravated by treatment with methanol.

Embryotoxicity of methanol in well-nourished and malnourished rats

1. The objective of the present study was to investigate whether maternal protein-energy malnutrition alters methanol-induced embryotoxic effects in rats. 2. On day 0 of pregnancy, dams were assigned at random to one of the following treatment groups: well-nourished methanol (WNM), well-nourished control (WNC), malnourished methanol (MNM) and malnourished control (MNC). Malnourished animals received half of the well-nourished food intake (ca 12 g/day) throughout pregnancy. Methanol was adminsitered by gavage (2.5 g/kg body weight) from gestation day 6 to 15. 3. Rats were weighed on days 0,6 to 15, and 21 of pregnancy. On day 21 rats were submitted to cesarean section. The number of implantations, living and dead fetuses, resorptions and corpora lutea was recorded. All fetuses were weighed, examined for externally visible malformations, fixed, and examined for skeletal anomalies after clearing and staining with Alizarin Red S. 4. An increased proportion of fetuses with skeletal malformations, particularly cervical extra ribs, was found in the methanol-treated groups (fetuses with skeletal malformations: WNC = 5.6 percent WNM = 45.4 percent, MNC = 3.8 percent, and MNM = 38.8 percent). Malnutrition produced fetal growth retardation, but did not cause any increase in the occurrence of gross structural malformations. The methanol-induced increase in the proportion of fetuses with extra ribs was not altered by malnutrition, but methanol potentiated the malnutrition-induced increase in the proportion of fetuses with sings of delayed ossification (WNC = 18.6 percent, WNM = 25.4 percent, MNC = 39.7 percent, and MNM = 78.4 percent). 5. These findings suggest that methanol-induced gross structural malformations are not affected by maternal malnutrition, but the delay in ossification caused by malnutrition is aggravated by treatment with methanol

Peri- and postnatal developmental toxicity of beta-myrcene in the rat.

beta-Myrcene (MYR) and essential oils containing this monoterpene have been widely used as scenting agents in cosmetics, detergents, soaps, and as flavouring additives in food and beverages. Recently, MYR was reported to be an analgesic substance and the active principle of lemongrass tea. Despite the importance of human exposure to MYR, its toxicological profile has not been comprehensively studied. The aim of this study was to provide data on the peri- and postnatal developmental toxicity of this terpene. MYR (0.25, 0.5, 1.0 and 1.5 g/kg) in corn oil was given by gavage to female Wistar rats from day 15 of pregnancy, parturition and throughout the period of lactation up to weaning (postnatal day 21). The progeny were examined at birth and subsequently to weaning. Mortality, weight gain and physical signs of postnatal development (ear unfolding, incisor eruption, fur development and eye opening) were evaluated. When the exposed offspring reached maturity (120 days) their reproductive capacity was assessed. No adverse effects on the offspring were seen with the lowest dose tested, but 0.5 g/kg and higher doses decreased birth weight, increased perinatal mortality and delayed the day of appearance of landmarks of postnatal development. Moreover, fertility was impaired in female offspring exposed to the two highest doses of MYR. From the data presented in this paper the no-observed-adverse-effect level for peri- and postnatal developmental toxicity could be set at 0.25 g beta-myrcene/kg body weight.

Study on embryo-foetotoxicity of beta-myrcene in the rat.

beta-Myrcene is a constituent of many essential oils that have been used extensively in cosmetic fragrances and as flavouring additives in the food industry. Recently, this monoterpene was reported to be an analgesic substance. Notwithstanding the widespread use of myrcene and essential oils containing myrcene in perfume and in food additives, experimental studies on the toxicity of this substance are still scarce. This study aimed to provide data on the embryo-foetotoxic potential of beta-myrcene in the rat. beta-Myrcene (0.25, 0.5 and 1.2 g/kg) in corn oil was given orally to Wistar rats from day 6 to 15 of pregnancy. Caesarean sections were performed on day 20 of pregnancy, and the number of resorptions and implantation sites were recorded. Foetuses were weighed, examined for external malformations, and fixed for visceral examination, or cleared and stained with Alizarin Red S for skeleton evaluation. No adverse effects were seen with the two lowest doses tested. Decreased weight gain during the first days of treatment and the death of one of 29 treated dams indicated that the highest dose tested (1.2 g/kg) induced maternal toxicity. A higher incidence of signs of retardation and of anomalies in the foetal skeleton indicated that 1.2 g/kg was also toxic to the rat embryo. From the data presented in this paper the no-observed-adverse-effect level for embryo-foetotoxicity could be set at 0.5 g beta-myrcene/kg body weight.

Single dose toxicity study of beta-myrcene, a natural analgesic substance.

The present study was undertaken to provide data on acute toxicity of beta-myrcene, a peripheral analgesic substance found in the essential oils of several plants. Although myrcene has long been used in perfumes and as a food additive, there is almost no information on its toxicological hazards. The acute oral toxicity of myrcene was low in rodents, with approximate lethal doses (ALD) of 5.06 g/kg body weight for mice and greater than 11.39 g/kg body weight for rats. Necropsy data did not reveal any relevant alteration in rats but histopathology findings in mice suggested that the liver and stomach may be target organs for myrcene toxicity after oral administration. Myrcene is highly irritant to the peritoneum, and deaths after intraperitoneal injection of this monoterpene in rats (ALD 5.06 g/kg body weight) and in mice (ALD 2.25 g/kg body weight) were probably due to drug-induced chemical peritonitis.

Single dose toxicity study of beta-myrcene, a natural analgesic substance

The present study was undertaken to provide date on acute toxicity of ß-myrcene, a peripheral analgesic substance found in the essential oils of several plants. Although myrcene has long been used in perfumes and as a food additive, there is almost no information on its toxicological hazards. The acute oral toxicity of myrcene was low in rodents, with with approximate lethal doses (ALD) of 5.06g/Kg body weight for mice and greater than 11.39 g/Kg body weight for rats. Necropsy data did not reveal any relevant alteration in rats but histophatology findings in mice suggested that the liver and stomach may be target organs for myrcene toxicity after oral administration. Myrcene is highly irritant to the peritoneum, and deaths after intraperitoneal injection of this monoterpene in rats (ALD 5.06 g/Kg body weight) and in mice (ALD 2.25 g/Kg body weight) were probably due to drug-induced chemical peritonitis