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At least 253 records · Page 14Linked to original sources
PubMed2005

[Anti-tumor effect of ethanol extracts from Thymus quinquecostatus Celak on human leukemia cell line].

OBJECTIVE: To screen the anti-tumor fraction of ethanol extracts from Thymus quinquecostatus Celak and investigate its anti-tumor effect on human leukemia cell line. METHODS: Ethyl acetate, n-butanol and acetone fractions were separated from the ethanol extracts of wild Thymus quinquecostatus Celak. Growth inhibiting effects of these extracts on human leukemia cell lines K562 and HL-60 were determined by live cell counting and cell growth curve analysis. The possible anti-tumor mechanism was studied by morphological analysis with norcantharidin as a positive control. RESULTS: Ethyl acetate fraction could significantly inhibit the proliferations of K562 and HL-60 cells, and the inhibiting effect depended on the concentration of ethyl acetate fraction. Ethyl acetate fraction could induce apoptosis of K562 and HL-60 cells. The n-butanol and acetone fractions had no significant inhibiting effect on K562 and HL-60 cells. CONCLUSION: Ethyl acetate fraction is the major anti-tumor fraction in ethanol extracts from Thymus quinquecostatus Celak.

Antineoplastic Agents, Phytogenic↗
PubMed1983

An inhibitory effect of sulfhydryl compounds in the assay of rat and mouse thymic terminal deoxynucleotidyl transferase (TdT).

Terminal deoxynucleotidyl transferase (TdT) was assayed in 100,000 X g supernatants of homogenized thymus using 3H-dGTP and an oligo p(dA)12-18 primer. 2-Mercaptoethanol (2-ME) caused a depression of activity with rat and mouse thymus extracts but increased activity using bovine or lamb thymus extracts. Glutathione (GSH), L-cysteine and dithiothreitol (DTT) also showed an inhibitory effect with the rat thymus extract. Inhibition was significant at concentrations of sulfhydryl compounds commonly included in TdT assays (1 mM-2 mM).

Animals↗
PubMedDate not supplied

[Postradiation disorders in the adenine-phosphoribosyltransferase pathway of AMP biosynthesis].

A study was made of the activity of adenine-phosphoribosyltransferase (EC 2.4.2.7), which catalizes the biosynthesis of AMP from adenine and 5-phospho-alpha-D-riboso-1-diphosphate, in extracts from thymus and liver during 24 h following irradiation of mice in a dose of 245.1 mC/kg (dose-rate of 9.16 X 10(-4)-9.0 X 10(-4) A/kg). Adenine-phosphoribosyltransferase activity of liver remains normal during the entire period of observation. In thymus extracts, the activity of the enzyme decreases down to 70-80% of the control level 3 h after irradiation, it is normalized after 6 h and increases up to 150-160% of the control level by the end of the first day of radiation sickness.

Adenine Phosphoribosyltransferase↗
PubMed1997

Antioxidant activities of some extracts of Thymus zygis.

The antioxidant activities of methanol and ethyl ether extracts obtained from Thymus zygis, collected during the flowering or non-flowering period, were evaluated and compared. To investigate this potential, extracts were tested on their capacity to react with diphenylpicrylhydrazyl (DPPH) in a homogeneous medium, and to inhibit Fe2+/ascorbate-induced membrane lipid peroxidation, as estimated by the formation of thiobarbituric acid-reactive substances (TBARS). Although methanol extracts reduce DPPH radicals more efficiently than ethyl ether extracts, suggesting a potent radical scavenger activity, the ethyl ether extracts were found to be most active in inhibiting lipid peroxidation in sarcoplasmic reticulum (SR) membranes. In addition, both extracts present peroxyl and superoxide radical scavenging activities. Peroxyl radicals were generated by the water soluble 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH) azoinitiator, and the scavenging activities of the extracts were measured by the inhibition of cis-parinaric acid (PnA) fluorescence decay in SR. Superoxide radicals were generated either by an enzymatic or a non-enzymatic system, and the scavenger ability was evaluated by the inhibition of nitroblue tetrazolium reduction. Methanolic extracts are more potent as scavengers of peroxyl and superoxide radicals than the ethyl ether extracts. Apparently, there is a relationship between antioxidant potency and the total phenolic groups content in each extract.

Amidines↗
PubMed1987

[Modification of radiogenic leukopenia].

In our investigations on rats was proofed the qualification of substances 2-Cyanoethyl Urea (CEH), Thymus-Extract and Lithium-carbonate for a potential reducing or shortening of the leucocyte-depression after whole-body irradiation. Intravenous applications of 2-Cyanoethyl Urea in Wistar rats showed no effect not only in the increase of leucocytes but also in variation in portions of leucocytes. In our investigations we could not influence radiogenic phase of leucopenia by application of CEH after 7 Gy whole-body irradiation. Intramuscular injections of thymus extract don't influence the number of leucocytes in peripheral blood in irradiated Wistar rats. The differential blood-count was uninfluenced. Increase in concentration of thymus extract and also higher frequency of the applications effect no changes in blood-count. Leucocyte depression after whole-body irradiation was independent of the application modus of thymus extract. Lithium-carbonate shows a significant increase of leucocytes in peripheral blood in dependence of dosage and frequency of application. After whole-body irradiation with 7 Gy under lithium therapy it was shown that on day 6th after irradiation leucocyte number was significantly higher than in controls. Radiogenic leucopenia phase was reduced significantly by lithium.

Aerosols↗
PubMed2006

Reevaluation of antimicrobial and antioxidant activity of Thymus spp. extracts before and after encapsulation in liposomes.

The antioxidant and antimicrobial activity of four Thymus species (boissieri, longicaulis, leucospermus, and ocheus) extracts were determined. Two methods (Rancimat and malondialdehyde by high-performance liquid chromatography) were used to measure the antioxidant action in comparison with common commercial antioxidants, including butylated hydroxytoluene and alpha-tocopherol. The extracts that presented high antioxidant activity were encapsulated in liposomes and their antioxidant action was again estimated. Thermal-oxidative decomposition of the samples (pure liposomes and encapsulating extracts) was studied using the differential scanning calorimetry method. The modification of the main transition temperature for the lipid mixture and the splitting of the calorimetric peak in the presence of the antioxidants were also demonstrated by differential scanning calorimetry. All extracts showed antioxidant and antimicrobial activities. Some extracts showed superior or equal antioxidant activity to alpha-tocopherol. When the extracts were encapsulated in liposomes, their antioxidant as well as antimicrobial activities proved to be superior from the same extracts in pure form.

Anti-Bacterial Agents↗
PubMed1991

[Chemotherapy and immunomodulating treatment of patients with multiple myeloma].

Prospective studies were carried out on the effectiveness of various treatment methods in 208 patients with plasmocytic myeloma. In 102 patients induction therapy was based exclusively on melphalan, in 106 cases polychemotherapy was used including vincristine, melphalan, carmustine, cyclophosphamide and prednisone. The differences in the per cent of patients with good response to treatment and in the survival time after treatment beginning were statistically not significant between these groups which suggests that polychemotherapy begun from the diagnosis of the disease is justified in patients with large mass of the neoplasm and poor prognostic factors. In 45 patients chemotherapy was supported by administration of immunomodulatory agents, including calf thymus extract in 25 cases, levamisole in 18 and interferon in 2. It was observed that maintenance of remission with chemotherapy and with immunomodulatory agents calf thymus extract or levamisole prolonged the survival of the patients. In cases of leucopenia the use of calf thymus extract facilitated chemotherapy by stimulation of myelopoiesis.

Adult↗
PubMed2003

Antimicrobial and antioxidant activity of the essential oil and methanol extracts of Thymus pectinatus Fisch. et Mey. Var. pectinatus (Lamiaceae).

The essential oil, obtained by using a Clevenger distillation apparatus, and water-soluble (polar) and water-insoluble (nonpolar) subfractions of the methanol extract of Thymus pectinatus Fisch. et Mey. var. pectinatus were assayed for their antimicrobial and antioxidant properties. No (or slight) antimicrobial activity was observed when the subfractions were tested, whereas the essential oil showed strong antimicrobial activity against all microorganisms tested. Antioxidant activities of the polar subfraction and the essential oil were evaluated using 2,2-diphenyl-1-picrylhydrazyl, hydroxyl radical, superoxide radical scavenging, and lipid peroxidation assays. The essential oil, in particular, and the polar subfraction of the methanol extract showed antioxidant activity. The essential oil was analyzed by GC/MS, and 24 compounds, representing 99.6% of the essential oil, were identified: thymol, gamma-terpinene, p-cymene, carvacrol, and borneol were the main components. An antimicrobial activity test carried out with fractions of the essential oil showed that the activity was mainly observed in those fractions containing thymol, in particular, and carvacrol. The activity was, therefore, attributed to the presence of these compounds. Other constituents of the essential oil, such as borneol, gamma-terpinene, and p-cymene, could be also taken into account for their possible synergistic or antagonistic effects. On the other hand, thymol and carvacrol were individually found to possess weaker antioxidant activity than the crude oil itself, indicating that other constituents of the essential oil may contribute to the antioxidant activity observed. In conclusion, the results presented here show that T. pectinatus essential oil could be considered as a natural antimicrobial and antioxidant source.

Anti-Bacterial Agents↗
PubMed2003

[The relationship between abnormal apoptosis and Fas expression of thymocytes from patients with myasthenia gravis].

AIM: To explore the roles of abnormalities of thymocytic abnormal apoptosis and its Fas expression in patients with myasthenia gravis (MG) in generation of autoimmune response. METHODS: The thymocytes were isolated and thymus extractive was prepared from fresh thymic tissue excised from MG patients. The proliferation of thymocyes was evaluated by MTT colorimetry. The apoptosis of thymocytes were examined by DNA electrophoresis. Expression of Fas was analyzed by a FACScan flow cytometry. Transcription and mutation of Fas gene were detected by RT-PCR and single-stranded conformation polymorphism ( SSCP) analysis. RESULTS: Thymus extractive could inhibit proliferation of normal thymocytes, while had no influence on the thymocytic proliferation of MG patients. The proliferation of thymocytes of both normal persons and MG patients could be inhibited by thymus extractive in the presence of dexamethasone. The inhibition rates were 58. 33% and 54. 26% respectively. The cocultured thymocytes with dexamethasone showed characteristic apoptosis pattern and the DNA electrophoresis exhibited 'ladder' appearance. The abnormal bands in Fas mRNA of partial MG patients' thymocytes were found by RT-PCR-SSCP analysis. CONCLUSION: Abnormalities of apoptosis and Fas gene expression of MG patients' thymocytes, and Fas gene mutation may be related to the pathogenesis and progression of MG.

Adolescent↗