Genotoxicity of an extract of Calendula officinalis L.

A fluid extract of Calendula officinalis L. displayed genotoxic properties when assayed for mitotic segregation in the heterozygous diploid D-30 of Aspergillus nidulans. The extract of Calendula exhibited dose-dependent toxicity and genotoxicity (both mitotic crossing-over and chromosome malsegregation being observed) to Aspergillus in the range of five plate concentrations from 0.1 to 1.0 mg of solids/ml assayed. Mutagenicity testing with the Salmonella/microsome assay in strains TA 1535, TA 1537, TA 98 and TA 100 was negative in a plate incorporation protocol, with concentrations ranging from 50 to 5000 microg/plate (+/- S9). The mouse bone marrow micronucleus test, where the extract was dosed orally up to 1 g/kg for 2 days, was also negative.

Activity of a nitroalkene derivative, 1-(5-bromofur-2-il)-2-bromo-2-nitroethene, in the Salmonella/microsome assay and the mouse bone marrow micronucleus test.

Mutagenicity of a substituted nitroalkene, 1-(5-bromofur-2-il)-2-bromo-2-nitroethene (BNF) was tested in the Salmonella/microsome assay using the strains TA 98, TA 100 and TA 100NR (nitroreductase deficient). BNF was a direct mutagen in TA 98 and TA 100; the response was lowered when exogenous metabolic activation (S9) was used. A further decrease in mutagenicity was observed in strain TA 100NR, as compared to the parental TA 100, which showed the involvement of nitroreduction in the overall response elicited by BNF. The micronucleus assay was carried out in Swiss male mice which were given a single i.p. dose of 10-20 mg/kg of BNF dissolved in peanut oil, bone marrow being sampled 24 and 48 h later. The micronucleated polychromatic erythrocyte counts (MNPCE) showed a weak response in the dose range of 10-17.5 mg/kg at the second sampling (48 h) and a significant rise for 20 mg/kg at 24 and 48 h.

Screening of medicinal plants for induction of somatic segregation activity in Aspergillus nidulans.

Knowledge about mutagenic properties of plants commonly used in traditional medicine is limited. A screening for genotoxic activity was carried out in aqueous or alcoholic extracts prepared from 13 medicinal plants widely used as folk medicine in Cuba: Lepidium virginicum L. (Brassicaceae): Plantago major L. and Plantago lanceolata L. (Plantaginaceae); Ortosiphon aristatus Blume, Mentha x piperita L., Melissa officinalis L. and Plectranthus amboinicus (Lour.) Spreng. (Lamiaceae); Cymbopogon citratus (DC.) Stapf (Poaceae); Passiflora incarnata L. (Passifloraceae); Zingiber officinale Roscoe (Zingiberaceae); Piper auritum HBK. (Piperaceae); Schinus terebinthifolius Raddi (Anacardeaceae) and Momordica charantia L. (Cucurbitaceae). A plate incorporation assay with Aspergillus nidulans was employed, allowing detection of somatic segregation as a result of mitotic crossing-over, chromosome malsegregation or clastogenic effects. Aspergillus nidulans D-30, a well-marked strain carrying four recessive mutations for conidial color in heterozygosity, which permitted the direct visual detection of segregants, was used throughout this study. As a result, only in the aqueous extract of one of the plants screened (Momordica charantia) a statistical significant increase in the frequency of segregant sectors per colony was observed, and consequently, a genotoxic effect is postulated.

Paramyxoviruses of the morbilli group in the wild hedgehog Erinaceus europeus.

Dead and sick hedgehogs (Erinaceus europeus) were examined, together with apparently healthy individuals, and paramyxo virus of the morbilli group was isolated. One animal's symptoms were similar to those caused by canine distemper and the virus isolate from faecal suspensions from this animal were antigenically related in various degrees to measles, canine distemper, rinderpest and PPRV viruses. Isolates from normal hedgehogs were found to belong to the same group. The variability and host specificity of members of paramyxo morbilli group virus are discussed and the role of natural infections of wild communities is considered in relation to disease in domestic animals and man.

Recovery of herpes simiae (B virus) from both primary and latent infections in rhesus monkeys.

The suspected ability of herpes simiae (B virus) to persist in a latent form has been confirmed in rhesus monkeys. The virus was recovered from primary oral lesions of 2 young monkeys and again, 6 months after disappearance of symptoms, from cultures of Gasserian ganglia taken from the same individuals. B virus was identified by its effects in vivo and in vitro and in cross neutralization tests with antisera to reference B virus and herpes simplex virus. Tests showed that the same virus was present in oral lesions and in ganglia. The one-way immunological relationship between herpes simplex virus and B virus was clearly shown in results of cross neutralization tests.

Latency of Herpes Simiae (B virus) in rabbits.

When small doses of herpes simplex virus (HSV) were given to rabbits a significant degree of protection was afforded against later infection with herpes simiae (B virus). Only 12/47 rabbits died within 3 weeks of receiving B virus dosages that would normally have proved lethal. B virus became latent in survivors and was recovered from brain and spinal cord suspensions from rabbits which died within 6 months and from dorsal root ganglia of rabbits which had survived for more than 2 years without overt signs of infection. A minority of the survivors tested also yielded HSV. Rabbits with latent B virus in the ganglia showed little or no detectable neutralizing antibody to B virus. The possibility is discussed that human populations having a high frequency occurrence of HSV antibody may include carriers of latent B virus.