Studies on brain biogenic amines in methanolic extract of Cuscuta reflexa Roxb. and Corchorus olitorius Linn. seed treated mice.
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The methanolic extract of both Cuscuta reflexa stem and Corchorus olitorius seed showed marked protection against convulsion induced by chemoconvulsive agents in mice. The catecholamines contained were significantly increased in the processed extract treated mice. The amount of GABA, which is most likely to be involved in seizure activity, was increased significantly in mice brain after a six week treatment. Results of the present study revealed that both the processed extracts showed a significant anticonvulsive property by altering the level of catecholamines and brain amino acids in mice. (+info)
Carotenoid specificity of light-harvesting complex II binding sites. Occurrence of 9-cis-violaxanthin in the neoxanthin-binding site in the parasitic angiosperm Cuscuta reflexa.
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The parasitic angiosperm Cuscuta reflexa has a highly unusual carotenoid composition in that it does not contain neoxanthin, an otherwise ubiquitous component of the major light-harvesting complex protein (LHCIIb) in all other higher plant species studied to date. Combined HPLC and mass spectrometric analysis has enabled us to detect in tissues of C. reflexa two new types of xanthophylls: lutein-5,6-epoxide and 9-cis-violaxanthin. We have isolated the LHCIIb complex from thylakoids and analyzed chlorophyll and carotenoid composition. The data show that the 9-cis-violaxanthin is present in amounts similar to that of neoxanthin in most plants. On the other hand, lutein-5,6-epoxide was found to be in substoichiometric quantities, suggesting a peripheral location similar to the loosely-associated all-trans-violaxanthin and also enabling suitable accessibility for the de-epoxidase (VDE). Absorption spectroscopy revealed close similarities of the excited state energies of neoxanthin and 9-cis-violaxanthin in vitro and in intact LHCIIb complex. Resonance Raman analysis clearly indicates a cis conformation of violaxanthin in the complex, confirming the pigment analysis data and proving that not only does violaxanthin replace neoxanthin as an intrinsic component of LHCIIb in C. reflexa but it also adopts the same 9-cis conformation of neoxanthin. These results suggest that the N1 binding site of LHCIIb preferentially binds 9-cis-5,6-epoxy carotenoids, which has implications for the features of this binding site and its role in the photosystem II antenna assembly and stability. (+info)
Chemical and toxicological evaluation of methanol extract of Cuscuta reflexa Roxb. stem and Corchorus olitorius Linn. seed on hematological parameters and hepatorenal functions in mice.
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Methanol extract of Cuscuta reflexa Roxb. stem (MECR) contain flavonoids (0.2%) and Corchorus olitorius Linn. seed (MECO) was found to contain steroids and cardenolide glycosides. Effects of multiple weekly dose of MECR (25, 50, 75 mg/kg, i.p.) and MECO (15, 20, 25 mg/kg, i.p.) on liver and kidney functions and hematological parameters in mice were studied. No significant alteration of RBC count and hemoglobin content was observed in all dose level of treatment in MECR and MECO treated mice whereas significant increase of clotting time was seen in moderate and high doses in both case. MECR and MECO both caused significant increase in WBC count only in high dose level of treatment. Both the extracts in medium and high dose level increased SGOT, SGPT, NPN and plasma cholesterol significantly. Serum alkaline phosphatase and total bilirubin were also increased by both moderate and high dose level of treatments in MECR and MECO treated mice respectively. Low dose of both the extract did not exhibit any significant change of creatinine and serum protein level. But high dose level of MECR and MECO significantly increased creatinine level. Increase in plasma cholesterol may be due to decrease in cholesterol catabolism owing to liver dysfunction of due to the intake of MECO itself as it was found to be steroid in nature. Elevated level of SGOT, SGPT and serum alkaline phosphatase activity in moderate and high dose level of weekly treated mice may be due to improper liver function following the treatment. Increased urea, non protein nitrogen and creatinine content in blood have been observed with impaired renal function. The slightly higher toxicity in case of MECO treated mice may be due to the presence of cardenolide glycosides in the ME of C. olitorius seed. However, low doses of MECR and MECO (25 and 15 mg/kg, i.p. respectively) did not exhibit any remarkable change on liver and kidney functions and hematological parameters. (+info)
New ELISA kits using C3 binding glycoprotein from Cuscuta europea detect mainly IgM CIC in rheumatoid arthritis and progressive systemic sclerosis, but not in systemic lupus erythematosus.
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Elevated levels of circulating immune complexes (CIC), containing IgG, IgM or IgA antibodies were detected in the sera of patients with autoimmune diseases. This might indicate a different biological meaning of the three isotypes of immunoglobulin (Ig) in the CIC. Each CIC assay detected only certain classes and subclasses of Ig in CIC material or fixed complement protein. In this study, a new method based on C3binding glycoprotein named CIF-ELISA and a well-known method ANTI-C3 ELISA, were used for quantitative assessment of IgM-CIC, IgG-CIC and IgA-CIC levels in human sera. A modified CIF-ELISA and ANTI-C3 ELISA for simultaneous detection of CIC, containing IgG, IgM and IgA, (stCIC), were also performed. The assays were evaluated on the same specially prepared samples: 55 normal sera, 99 sera from rheumatoid arthritis (RA), 88 sera from systemic lupus erythematosus (SLE), and 27 sera from progressive systemic sclerosis (PSS). We found that the sensitivity of the tests used varied depending on the diseases studied. CIF-ELISA displayed higher sensitivity of IgM-CIC when compared to ANTI-C3 ELISA in RA patients (40.0 and 20.95%, respectively) and PSS (44.43 and 37.04%, respectively). Results for the sensitivity of IgA-CIC were in adverse direction in the RA group (14.28 and 19.05%) and PSS (14.81 and 25.93%) by both methods. It was also established that the concordance of IgM-CIC positives by both methods was 48.84% in RA and 46.67% in PSS, while in SLE it was 18.78%. These results are most probably due to the different assay abilities to detect antibody isotype of the CIC material and help to explain what specific role each Ig isotype in CIC has in the course of the disease. (+info)
Evaluation of psychopharmacological effects of petroleum ether extract of Cuscuta reflexa Roxb. stem in mice.
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The petroleum ether extract of Cuscuta reflexa Roxb. stem (PECR) was evaluated for its psychopharmacological activities in several experimental models using Swiss albino mice. The PECR was found to cause significant reduction in spontaneous activity and exploratory behavioral profiles. It also showed reduction in muscle relaxant activity by rotarod, 30 degrees inclined screen tests and showed significant analgesic properties as well as potentiated remarkably the pentobarbitone sodium, diazepam and meprobamate--induced sleeping time. All these results were compared with respective controls for the evaluation of significance. The presence of steroids in the PECR might he responsible for psychopharmacological activities. (+info)
Plastid genome structure and loss of photosynthetic ability in the parasitic genus Cuscuta.
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The genus Cuscuta (dodder) is composed of parasitic plants, some species of which appear to be losing the ability to photosynthesize. A molecular phylogeny was constructed using 15 species of Cuscuta in order to assess whether changes in photosynthetic ability and alterations in structure of the plastid genome relate to phylogenetic position within the genus. The molecular phylogeny provides evidence for four major clades within Cuscuta. Although DNA blot analysis showed that Cuscuta species have smaller plastid genomes than tobacco, and that plastome size varied significantly even within one Cuscuta clade, dot blot analysis indicated that the dodders possess homologous sequence to 101 genes from the tobacco plastome. Evidence is provided for significant rates of DNA transfer from plastid to nucleus in Cuscuta. Size and structure of Cuscuta plastid genomes, as well as photosynthetic ability, appear to vary independently of position within the phylogeny, thus supporting the hypothesis that within Cuscuta photosynthetic ability and organization of the plastid genome are changing in an unco-ordinated manner. (+info)
Transfer of phloem-mobile substances from the host plants to the holoparasite Cuscuta sp.
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During the development of the haustorium, searching hyphae of the parasite and the host parenchyma cells are connected by plasmodesmata. Using transgenic tobacco plants expressing a GFP-labelled movement protein of the tobacco mosaic virus, it was demonstrated that the interspecific plasmodesmata are open. The transfer of substances in the phloem from host to the parasite is not selective. After simultaneous application of (3)H-sucrose and (14)C-labelled phloem-mobile amino acids, phytohormones, and xenobiotica to the host, corresponding percentages of the translocated compounds are found in the parasite. An open continuity between the host phloem and the Cuscuta phloem via the haustorium was demonstrated in CLSM pictures after application of the phloem-mobile fluorescent probes, carboxyfluorescein (CF) and hydroxypyrene trisulphonic acid (HPTS), to the host. Using a Cuscuta bridge (14)C-sucrose and the virus PVY(N) were transferred from one host plant to the another. The results of translocation experiments with labelled compounds, phloem-mobile dyes and the virus should be considered as unequivocal evidence for a symplastic transfer of phloem solutes between Cuscuta species and their compatible hosts. (+info)
Volatile chemical cues guide host location and host selection by parasitic plants.
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The importance of plant volatiles in mediating interactions between plant species is much debated. Here, we demonstrate that the parasitic plant Cuscuta pentagona (dodder) uses volatile cues for host location. Cuscuta pentagona seedlings exhibit directed growth toward nearby tomato plants (Lycopersicon esculentum) and toward extracted tomato-plant volatiles presented in the absence of other cues. Impatiens (Impatiens wallerana) and wheat plants (Triticum aestivum) also elicit directed growth. Moreover, seedlings can distinguish tomato and wheat volatiles and preferentially grow toward the former. Several individual compounds from tomato and wheat elicit directed growth by C. pentagona, whereas one compound from wheat is repellent. These findings provide compelling evidence that volatiles mediate important ecological interactions among plant species. (+info)