Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “SENECIO”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed2003

Sporophytic self-incompatibility in Senecio squalidus L (Asteraceae)--the search for S.

Senecio squalidus (Oxford Ragwort) is being used as a model species to study the genetics and molecular genetics of self-incompatibility (SI) in the Asteraceae. S. squalidus has a strong system of sporophytic SI (SSI) and populations within the UK contain very few S alleles probably due to a population bottleneck experienced on its introduction to the UK. The genetic control of SSI in S. squalidus is complex and may involve a second locus epistatic to S. Progress towards identifying the female determinant of SSI in S. squalidus is reviewed here. Research is focused on plants carrying two defined S alleles, S(1) and S(2). S(2) is dominant to S(1) in pollen and stigma. RT-PCR was used to amplify three SRK-like cDNAs from stigmas of S(1)S(2) heterozygotes, but the expression patterns of these cDNAs suggest that they are unlikely to be directly involved in SI or pollen-stigma interactions in contrast to SSI in the Brassicaceae. Stigma-specific proteins associated with the S(1) allele and the S(2) allele have been identified using isoelectric focusing and these proteins have been designated SSP1 (Stigma S-associated Protein 1) and SSP2. SSP1 and SSP2 cDNAs have been cloned by 3' and 5' RACE and shown to be allelic forms of the same gene, SSP. The expression of SSP and its linkage to the S locus are currently being investigated. Initial results show SSP to be expressed exclusively in stigmas and developmentally regulated, with maximal expression occurring at and just before anthesis when SI is fully functional, SSP expression being undetectable in immature buds. Together these data suggest that SSP is a strong candidate for a Senecio S-gene.

Fertility↗
PubMedDate not supplied

Pyrrolizidine alkaloid profiles of some Senecio species from Egypt.

Alkaloid profiles of two Egyptian Senecio species (Senecio aegyptius var. discoideus and S. desfontainei) in addition to a cultivated species (S. cineraria) were studied using capillary GLC and GLC-mass spectrometry with respect to pyrrolizidine alkaloids (PAs). Four alkaloids were identified in S. aegyptius var. discoideus, 8 in S. desfontainei and 13 in S. cineraria. Some of these alkaloids have not been reported from these plants. The alkaloidal pattern of different plant organs (flowers, leaves, stem, root) were also investigated. Senecionine has been found to be a one of the major alkaloid in all studied species, it was isolated and its structure was elucidated by 1H- and 13C-NMR.

Chromatography, Gas↗
PubMed1984

Mutagenic responses of tansy ragwort (Senecio jacobaea) plant, pyrrolizidine alkaloids and metabolites in goat milk with the Salmonella/mammalian-microsome mutagenicity test.

Tansy ragwort (Senecio jacobaea ) was evaluated for animal and human health hazard using the Salmonella/mammalian-microsome mutagenicity test. An acetone extract of tansy ragwort (TR) produced a negative mutagenic response for bacterial tester strains TA1535 and TA100 and a toxic response in tester strains TA1537 and TA98. Assay of this extract in the presence of mammalian liver microsomes (S-9) resulted in positive mutagenic responses in tester strains TA1535, TA1537, TA98 and TA100. Species differences were evaluated by use of liver microsome preparations from induced rat and uninduced sheep, beef, hamster, trout and rat. Only a slight species difference was demonstrated. A mixture of pyrrolizidine alkaloids (PA), extracted from TR flowers, produced a negative response in tester strains TA1535, TA1537, TA98 and TA100. A negative response was also demonstrated when the TR flower PA mixture was assayed with the Salmonella tester strains and induced rat liver microsomes ( IRLM ). A mixture of PA extracted from Senecio longilobus also produced a negative response. The major PA present in TR, jacobine , produced a negative response without and with IRLM exposure in tester strains TA1535, TA1537, TA98 and TA100. Another similar PA, monocrotaline, found in various Crotalaria species also gave a negative response. Milk from TR-fed goats was evaluated for mutagenic response. Milk from goats not receiving TR and from goats receiving TR at a level of 1% of their body weight/day via rumen cannula produced a negative response without liver microsomes present. Milk from TR-fed goats, however, yielded both negative and marginally positive responses for different combinations of tester strains and liver microsome preparations.

Animals↗
PubMed2003

[Advances in studies on chemical constituents of Senecio].

The large cosmopolitan genus Senecio, a perennial medicinal herb of the family compositae, has been utilized as a anthmicrobial agent. A variety of pyrrolizidine alkaloids and furanoeremophilanes are widespread in the genus Senecio, which are responsible for the hepatotoxic and carchnogenic effects. Some of them have been screened for anti-tumour activity, but their liver toxicity renders their use in chemotherapy. This article reviews the recent advances in chemical constituents, identification methods and pharmacological activities of it.

Animals↗
PubMed2005

Recent, allopatric, homoploid hybrid speciation: the origin of Senecio squalidus (Asteraceae) in the British Isles from a hybrid zone on Mount Etna, Sicily.

Homoploid hybrid speciation occurs through stabilization of a hybrid segregate (or segregates) isolated by premating and/or postmating barriers from parent taxa. Theory predicts that ecological and spatial isolation are of critical importance during homoploid hybrid speciation, and all confirmed homoploid hybrid species are ecologically isolated from their parents. Until recently, such species have been identified long after they originated, and consequently it has not been possible to determine the relative importance of spatial and ecological isolation during their origin. Here we present evidence for the recent origin (within the past 300 years) of a new homoploid hybrid species, Senecio squalidus (Asteraceae), in the British Isles, following long-distance dispersal of hybrid material from a hybrid zone between S. aethnensis and S. chrysanthemifolius on Mount Etna, Sicily, Italy. Historical records show that such hybrid material from Sicily was introduced to the Oxford Botanic Garden in Britain in the early part of the 18th century and that S. squalidus began to spread from there after approximately 90 years. A survey of randomly amplified polymorphic DNA/intersimple sequence repeats (RAPD/ISSR) marker variation demonstrated that S. squalidus is a diploid hybrid derivative of S. aethnensis and S. chrysanthemifolius that grow at high and low altitudes, respectively, on Mount Etna and that form a hybrid zone at intermediate altitudes. Senecio squalidus contained 11 of 13 RAPD/ISSR markers that were recorded at high frequency in S. chrysanthemifolius but were absent or occurred at low frequency in S. aethnensis, and 10 of 13 markers for which the reverse was true. Bayesian admixture analysis showed that all individuals of S. squalidus surveyed were of mixed ancestry with relatively high mean proportions of ancestry derived from both S. chrysanthemifolius and S. aethnensis (0.644 and 0.356, respectively). We argue that long-distance isolation of hybrid material from its parents on Mount Etna would have helped favor the origin and establishment of S. squalidus in the British Isles, regardless of whether the initial hybrid material introduced to Britain was preadapted to local conditions.

Altitude↗
PubMed1985

Toxicity of Riddell's groundsel (Senecio riddellii) to cattle.

The toxicity of Riddell's groundsel (Senecio riddellii) fed to calves in gelatin capsules, by gavage, or mixed in their hay ration was determined. Dosages were varied according to the pyrrolizidine alkaloid (PA) content of the plant, and the calves' responses were measured by clinical signs, serum enzyme changes, survival time, and histopathologic changes. Calves fed S riddellii to provide 10 mg of PA/kg of body weight/day in capsules or by gavage for 20 consecutive days did not develop clinical signs of seneciosis and did not have meaningful serum enzyme changes. However, feedings of the plant that provided 15 to 20 mg of PA/kg/day or more (gavaged or fed in capsules for the same time period) resulted in high mortality. The Senecio plant mixed in calves' hay ration was eaten slowly and reluctantly and was tolerated at dosages greater than 20 mg/kg/day, emphasizing that the toxicity was dependent on the rate at which the dosage was consumed and that mortality was not necessarily dependent on the cumulative dosage. Because of its high PA content, S riddellii presents a great hazard to cattle managed under conditions where they can consume quantities of the plant in short periods of time.

Animals↗
PubMed1995

[Veno-occlusive liver disease due to intake of Senecio vulgaris tea].

Veno-occlusive liver disease (VOLD) is a cause of portal hypertension by non thrombotic obstruction of hepatic venous drainage attributed to multiple etiologies (toxic, irradiation, antineoplastic, conditioning for bone marrow transplantation). One case of VOLD in a senile patient due to continuous two year consumption of Senecio vulgaris tea is reported. This compound, which has a high pyrrolizidine alkaloid content induced a subacute course of portal hypertension and death. The clinicopathologic features of VOLD and the etiopathogenesis in relation to the pyrrolizidine alkaloids present in Senecio vulgaris are discussed. The need for considering the history of medicinal plant ingestion in patients under portal hypertension studies are strongly recommended as is the advice regarding the possible dangers involved in the inappropriate use of remedies provided by herbalists.

Aged↗
PubMed1994

Pyrrolizidine alkaloidosis in Argentinian cattle caused by Senecio selloi.

A herd of 135 Aberdeen Angus cows were grazing on pastures containing abundant Senecio selloi in the eastern region of Buenos Aires Province, Argentina. Some undiagnosed deaths were observed during 1989. In 1990 the death count raised to 38 animals, all of them showing the same clinical signs and gross and histopathological lesions. The time from the start of signs to death varied from 2 to 6 d. The most conspicuous signs were distention of the abdominal cavity and moderate icterus of mucous membranes. At necropsy, large amounts of fluid were in the abdominal cavity, there were lesions in the digestive tract, kidneys and mesenteric lymph nodes, and the liver was enlarged and fibrous. Histopathology showed the hepatic parenchyma replaced by fibrous tissue with marked megalocytosis. The signs and lesions were consistent with those produced by pyrrolizidine alkaloids. An abundance of Senecio selloi resulted in a diagnosis of poisoning from this plant. This is the first report of toxicity due to this plant species in Argentina.

Animals↗
PubMedDate not supplied

[Hepatic veno-occlusive disease associated with ingestion of Senecio tephrosioides].

A case of hepatic veno-occlusive disease (HVOD) in a 38 year-old woman is reported. She had occasionally consumed "Huamanrripa" (Senecio tephrosioides) as a cough remedy for many years. She was hospitalized because she had presented abdominal pain, jaundice and anasarca during 10 weeks. The histological studies of hepatic biopsy showed pronounced congestion to centrilobulillar predominance, focus of necrosis and a reversed lobulation pattern in some areas. In the next 13 months she was hospitalized four times due to complications of portal hypertension. This is the first reported case of HVOD associated with S tephrosioides ingestion. It is very probable that this plant used in peruvian traditional medicine contains pyrrolizidine alkaloids, hepatic and nephrotoxic substances that are present in other species of Senecio genus. Due to present popularity of alternative medicine, an increment in HVOD incidence is expected.

Adult↗
PubMed1976

Changes in calves and rats consuming milk from cows fed chronic lethal doses of Senecio jacobaea (tansy ragwort).

Chronic lethal doses of Senecio jacobaea, which contains 6 pyrrolizidine alkaloids, were fed to 6 cows close to parturition. Their calves were allowed to suckle for 40 to 126 days to determine whether pyrrolizidine alkaloids or their toxic metabolites had been passed into the cow's milk. Histopathologic changes were not detected in the calves consuming the milk; however, clinical chemical tests suggested the presence of hepatic biochemical lesions. Rats gavaged daily for 30 days with milk from Senecio-fed cows were not grossly or histopathologically affected.

Animals↗
PubMed1985

Determination of pyrrolizidine alkaloids in Senecio inaequidens D.C. by capillary gas chromatography.

A study of the toxic pyrrolizidine alkaloids contained in Senecio inaequidens D.C., an infestant species of the Senecio genus, widespread in the North East of Italy, is reported. Five of these compounds, senecivernine, senecionine, integerrimine, retrorsine and an analogue of retrorsine, were identified by means of capillary gas chromatography and capillary gas chromatography-mass spectrometry.

Chromatography, Gas↗
PubMedDate not supplied

Effects of microsomal enzyme induction on the toxicity of pyrrolizidine (Senecio) alkaloids.

Effects of microsomal enzyme induction by phenobarbital (PB) injection (ip) and ingestion of Eucalyptus globulus foliage or phenothiazine (PT) on the toxicity of pyrrolizidine alkaloids (PA) or dried plant material of Senecio longilobus (SL) and Senecio jacobaea (SJ) were evaluated in rats. The oral median lethal doses (LD50) for a PA mixture extracted from SL at 72, 144, and 168 h post PA administration were approximately greater than 320, 190, and 160 mg/kg, respectively. Induction of mixed-function oxidase (MFO) activity by PB or dietary eucalyptus leaves resulted in only a marginal effect on the acute LD50, with no effective change at 168 h. The LD50 values at 72, 144, and 168 h for PB-treated rats were approximately 320, 190, and 160 mg/kg, and for eucalyptus treated rats approximately 127, 133, and 133 mg/kg, respectively. Dietary PT did not alter the toxicity of SJ but did cause reductions in feed intake and average daily gain. Supplemental cysteine increased (p less than 0.05) survival time in SJ-consuming rats, with a concomitant increase (p less than 0.05) in SJ ingestion, and caused slight increases in average daily gain. The simultaneous addition of cysteine and PT to an SJ-containing diet resulted in an increased (p less than 0.05) survival time over SJ and SJ + PT diet groups and a slight decrease in survival time compared to the SJ + cysteine group.

Animals↗
PubMed1979

Modification of Herbicide Binding to Photosystem II in Two Biotypes of Senecio vulgaris L.

THE PRESENT STUDY COMPARES THE BINDING AND INHIBITORY ACTIVITY OF TWO PHOTOSYSTEM II INHIBITORS: 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron [DCMU]) and 2-chloro-4-(ethylamine)-6-(isopropyl amine)-S-triazene (atrazine). Chloroplasts isolated from naturally occurring triazine-susceptible and triazine-resistant biotypes of common groundsel (Senecio vulgaris L.) showed the following characteristics. (a) Diuron strongly inhibited photosynthetic electron transport from H(2)O to 2,6-dichlorophenolindophenol in both biotypes. Strong inhibition by atrazine was observed only with the susceptible chloroplasts. (b) Hill plots of electron transport inhibition data indicate a noncooperative binding of one inhibitor molecule at the site of action for both diuron and atrazine. (c) Susceptible chloroplasts show a strong diuron and atrazine binding ((14)C-radiolabel assays) with binding constants (K) of 1.4 x 10(-8) molar and 4 x 10(-8) molar, respectively. In the resistant chloroplasts the diuron binding was slightly decreased (K = 5 x 10(-8) molar), whereas no specific atrazine binding was detected. (d) In susceptible chloroplasts, competitive binding between radioactively labeled diuron and non-labeled atrazine was observed. This competition was absent in the resistant chloroplasts.We conclude that triazine resistance of both intact plants and isolated chloroplasts of Senecio vulgaris L. is based upon a minor modification of the protein in the photosystem II complex which is responsible for herbicide binding. This change results in a specific loss of atrazine (triazine)-binding capacity.

Journal Article↗
PubMed1990

Chronic hepato-toxicity of Senecio erraticus in calves from two 50-day feeding periods in consecutive years.

One-year-old male Holstein Fresian calves were fed low doses of Senecio erraticus during two 50-d periods in consecutive years to determine its chronic effect on the liver. Toxic liver effects were determined by monitoring serum levels of hepatic enzymes, bromosulphthalein retention (BSP), and histopathological changes in the liver at times before, during and after Senecio ingestion. A gradual increase in BSP retention was observed at days 60 and 90 during the first feeding period. Histological studies of the liver showed hepatocellular megalocytosis and karyomegaly, and hypertrophy of Kupffer cells in both groups. Periportal fibrosis, bile duct proliferation and the presence of periportal hyperchromatic and hypertrophic hepatocytes was seen after the second feeding period.

Age Factors↗
PubMed1982

Carcinogenic and mutagenic activity of an alkaloidal extract of Senecio nemorensis ssp. fuchsii.

The alkaloidal residue obtained after extraction of dried and pulverized Senecio nemorensis ssp. fuchsii contains two pyrrolizidine alkaloids, i.e. fuchsisenecionine and senecionine. In a chronic experiment doses of 8 mg/kg and 40 mg/kg b.w. of the alkaloidal extract were given five times a week by gavage to male and female Sprague-Dawley rats. The study was terminated after 114 weeks. Repeated serum analysis demonstrated a dose-related elevation of serum glutamic oxalacetic transaminase (SGOT), serum glutamic pyruvic transaminase (SGPT) and alkaline phosphatase (AP). Beside its hepatotoxic effect, the treatment proved to be hepatocarcinogenic, showing female rats to be more sensitive than males. Tumors diagnosed were of hepatocellular and angiogenic origin. In age-adjusted analysis the occurrence of these neoplasms revealed a clear dose-related trend (p less than 0.00005). In the in-vitro mutagenicity test system with V 79 Chinese hamster cells, the alkaloidal extract exerted a weak but dose-related mutagenic activity. Under the conditions used the alkaloidal extract of Senecio nemorensis ssp. fuchsii is a genotoxic carcinogen.

Alkaline Phosphatase↗
PubMed2003

A triterpene ozonide from Senecio selloi.

From the dried and fresh aerial parts of Senecio selloi Spreng, De Candolle (Asteraceae), the new triterpene ozonide 1 was isolated. Its structure was elucidated by NMR experiments, including inverse techniques HMQC and HMBC and by synthesis from the precursor 2 In contrast to natural peroxides, no antiplasmodial activity was detected for the ozonide 1.

Antimalarials↗
PubMed2004

Isomeric eremophilane lactones from Senecio tsoongianus.

From the whole plant of Senecio tsoongianus, two pairs of epimers, tsoongianolides A (1) and B (2), and tsoongianolides C (3) and D (4), and two new sesquiterpene lactones, tsoongianolides E (5) and F (6), all of which possess the eremophilane skeleton, were isolated. Two known eremophilane dimers (7) and (8) were also obtained from this species. Their absolute structures were elucidated by 1D- and 2D-NMR techniques and by X-ray diffraction studies, along with chemical evidence.

Isomerism↗
PubMed1988

Identification of senecionine and senecionine N-oxide as antifertility constituents in Senecio vulgaris.

The MeOH extract of Senecio vulgaris L., administered po to rats on Days 1-10 postcoitum, significantly decreased the number of normal fetuses per pregnant rat found at autopsy on Day 16. Additional experiments showed a similar activity for its hepatotoxic constituents senecionine and senecionine N-oxide, suggesting that the latter two compounds were probably responsible for the effect seen with the extract. No antifertility effects were seen in MeOH extract-treated hamsters.

Animals↗