The Experts below are selected from a list of 1419 Experts worldwide ranked by ideXlab platform
Krzysztof Gulewicz - One of the best experts on this subject based on the ideXlab platform.
-
Uncaria tomentosa Leaves Decoction Modulates Differently ROS Production in Cancer and Normal Cells, and Effects Cisplatin Cytotoxicity.
Molecules (Basel Switzerland), 2017Co-Authors: Anita Kośmider, Mieczysław Kuraś, Krzysztof Gulewicz, Edyta Czepielewska, Wioleta Pietrzak, Renata Nowak, Grażyna NowickaAbstract:Uncaria tomentosa is a woody vine with a long history of use in traditional Peruvian medicine and nowadays supplements containing this vine as ingredient are available. Immunomodulating, anti-inflammatory and anticancer properties of Uncaria tomentosa have been suggested and attributed mainly to the presence of tetracyclic or pentacyclic oxindole alkaloids. However, the synergic action of different compounds occurring in extracts and modulation of redox processes may significantly influence the anticancer activity of Uncaria tomentosa. The aim of the present study was to investigate for the first time the cytotoxic effects of the tetracyclic alkaloids free aqueous extract (decoction) of dried Uncaria tomentosa leaf blades in normal and cancer cells, and to assess the effect of the tested extract on cisplatin (CDDP) cytotoxicity. Tested Uncaria tomentosa extract was not cytotoxic for NHDF cells, but demonstrated cytotoxic effect against HepG2 cells. The extract increased ROS production in HepG2 cells, which resulted in decreased GSH level, leading to apoptosis of these cells through activation of caspase-3 and caspase-7. A reduction of NF-κB active form was observed in cancer cells. In normal cells the extract did not affect ROS production, GSH level and NF-κB activity, and maintained cell viability. HepG2 cells incubation with Uncaria tomentosa decoction and simultaneously with CDDP resulted in an increase in CDPP cytotoxic activity against HepG2, while under the same conditions Uncaria tomentosa prevents NHDF cell viability reduction due to CDDP. The results indicate that Uncaria tomentosa leaves decoction modulates differently cancer and normal cells oxidative metabolism and, enhanced cytotoxicity of CDDP against cancer cells and at the same time increased normal healthy cells resistance to cisplatin. Further studies are needed to confirm our observations and to describe underlying molecular mechanism, and the potential usefulness of Uncaria tomentosa decoction in adjuvant therapy for cancer.
-
Studies of biological properties of Uncaria tomentosa extracts on human blood mononuclear cells.
Journal of ethnopharmacology, 2012Co-Authors: Milena Bors, Radosław Pilarski, Krzysztof Gulewicz, Jaromir Michałowicz, Paulina Sicińska, Bożena BukowskaAbstract:Abstract Ethnopharmacological relevance Uncaria tomentosa (Willd.) DC is a lignified climbing plant from South and Central America, which (under the name of “vilcacora” or “cat's claw”) has become highly popular in many countries due to its proven immunostimmulatory and anti-inflammatory activities and also with respect to its anticancer and antioxidative effects. There are insufficient data on the mechanism of U. tomentosa action on normal blood mononuclear cells. Aim of the study The aim of the study was to analyze the impact of ethanol and aqueous extracts from bark and leaves of Uncaria tomentosa on the structure and function of human mononuclear cells and to find out whether the kind of extractant used modulates biological activity of the extracts studied. Materials and methods Plant material consisted of four different extracts: (1) ethanol extract from leaves, (2) aqueous extract from leaves, (3) ethanol extract from bark and (4) aqueous extract from bark. The effect of these extracts on protein damage as well as on free-radical formation in human peripheral blood mononuclear cells was analyzed. Moreover, changes in viability, size, and granularity as well as apoptotic alterations in human blood mononuclear cells exposed to U. tomentosa extracts were investigated. Results The oxidative changes were observed in mononuclear blood cells exposed to both ethanol and aqueous extracts obtained from bark and leaves. Moreover, in the cells studied the extracts from U. tomentosa induced apoptosis and a decrease in viability of mononuclear blood cells, with the exception of aqueous extract from leaves. Additionally, no statistically significant changes in the cell size were observed both for aqueous extracts from leaves and bark. Changes in the blood mononuclear cell granularity were observed at 250 μg/mL for all extracts examined. The strongest changes were observed for the ethanol extract of the bark, which increased cell granularity at 50 μg/mL and changed cell size at 100 μg/mL. Conclusion The conducted research showed differences in biological activity between aqueous and ethanol extracts. It was observed that ethanol extracts exhibited stronger negative effects on mononuclear blood cells. The kind of extractant used had a significant influence of the chemical composition of the tested extracts. The ethanol extract from bark containing a high amount of polyphenols and alkaloids revealed the highest pro-apoptotic effect.
-
Inhibitory mechanisms of two Uncaria tomentosa extracts affecting the Wnt-signaling pathway.
Phytomedicine : international journal of phytotherapy and phytopharmacology, 2010Co-Authors: Carmen Magdalena Gurrola-díaz, Krzysztof Gulewicz, Pedro Macedonio García-lópez, Radoslaw Pilarski, Susanne DihlmannAbstract:Uncaria tomentosa ("uña de gato"; "cat's claw"), a woody vine native to the Amazon rainforest, is commonly used in South American traditional medicine to treat a broad spectrum of diseases. Although recent studies have reported anti-inflammatory and anti-proliferative properties of different alkaloids extracted from this plant, the underlying molecular mechanisms of these effects have not been elucidated yet. Our study investigates the inhibitory mechanisms of Uncaria tomentosa extracts on the Wnt-signaling pathway, a central regulator of development and tissue homoeostasis. A modified cell-based luciferase assay for screening inhibitors of the Wnt-pathway was used for analysis. Three cancer cell lines displaying different levels of aberrant Wnt-signaling activity were transfected with Wnt-signaling responsive Tcf-reporter plasmids and treated with increasing concentrations of two Uncaria tomentosa bark extracts. Wnt-signaling activity was assessed by luciferase activity and by expression of Wnt-responsive target genes. We show that both, an aqueous and an alkaloid-enriched extract specifically inhibit Wnt-signaling activity in HeLa, HCT116 and SW480 cancer cells resulting in reduced expression of the Wnt-target gene: c-Myc. The alkaloid-enriched extract (B/S(rt)) was found to be more effective than the aqueous extract (B/W(37)). The strongest effect was observed in SW480 cells, displaying the highest endogenous Wnt-signaling activity. Downregulation of Wnt-signaling by a dominant negative-TCF-4 variant in non-cancer cells rendered the cells insensitive towards treatment with B/S(rt). B/Srt was less toxic in non-cancer cells than in cancer cells. Our data suggest that the broad spectrum of pharmacological action of Uncaria tomentosa involves inhibition of the Wnt-signaling pathway, downstream of beta-Catenin activity.
-
Evaluation of biological activity of Uncaria tomentosa (Willd.) DC. using the chicken embryo model.
Folia biologica, 2009Co-Authors: Radosław Pilarski, Marek Bednarczyk, Krzysztof GulewiczAbstract:The biological activity of Uncaria tomentosa (Willd.) DC. (cat's claw) was evaluated by application of the chicken embryo model. Among three groups of eggs (n = 360) with twelve-day old embryos, two were injected with different doses of cat's claw extracts (0.0492 and 0.492 mg/200 lambda). To the third control group 200 lambda of physiological salt was applied. All eggs were incubated in conventional forced-air apparatus until hatched. Hatchability, chicken weight and wholesomeness were analyzed. Selected parameters of blood including number of erythrocytes (RBC), number of leukocytes (WBC), mean red cell volume (MCV), hematocrit (HCT), hemoglobin concentration (HGB), mean amount of cell hemoglobin (MCH), mean cell hemoglobin concentration (MCHC) and embryo weight (MAS) were assayed and compared. Significant differences with ANOVA were observed for MCV (P = 0.002), MCHC (P = 0.00001) and MCH (P = 0.02). Applying the chicken embryo model brought new information about the biological activity of U. tomentosa showing an unfavourable effect on some morphological blood parameters.
-
Effect of Alkaloid-Free and Alkaloid-Rich preparations from Uncaria tomentosa bark on mitotic activity and chromosome morphology evaluated by Allium Test
Journal of ethnopharmacology, 2008Co-Authors: Mieczysław Kuraś, Radosław Pilarski, Julita Nowakowska, Alicja M. Zobel, Krzysztof Brzost, J. Antosiewicz, Krzysztof GulewiczAbstract:Abstract Ethnopharmacological revelance Uncaria tomentosa (Willd.) DC. is the most popular Peruvian plant, used in folk medicine for different purposes. It contains thousands of active compounds with great content of alkaloids. Aim of study Two different fractions of Alkaloid-Rich and Alkaloid-Free were researched on chromosome morphology, mitotic activity and phases indexes. Materials and methods Cells of Allium Test (meristematic cells of root tips) were incubated up to 24 h in different concentrations of Alkaloid-Free and Alkaloid-Rich fraction obtained from Uncaria tomentosa bark followed by 48 h of postincubation in water. The chromosome morphology was analyzed and the content of mitotic and phase indexes were done. Individual compounds, oxindole alkaloids, phenolic compounds and sugars were determined. Results In Alkaloid-Rich and Alkaloid-Free fractions (different in chemical composition) we observed condensation and contraction of chromosomes (more in Alkaloid-Rich) with retardation and/or inhibition of mitoses and changed mitotic phases. Postincubation reversed results in the highest concentration which was lethal (in mostly Alkaloid-Rich fraction). Conclusions Our studies indicate that different action can depend on different groups of active compounds in a preparation either containing alkaloids or not. Other fraction analysis may be useful in the future.
Radosław Pilarski - One of the best experts on this subject based on the ideXlab platform.
-
Studies of biological properties of Uncaria tomentosa extracts on human blood mononuclear cells.
Journal of ethnopharmacology, 2012Co-Authors: Milena Bors, Radosław Pilarski, Krzysztof Gulewicz, Jaromir Michałowicz, Paulina Sicińska, Bożena BukowskaAbstract:Abstract Ethnopharmacological relevance Uncaria tomentosa (Willd.) DC is a lignified climbing plant from South and Central America, which (under the name of “vilcacora” or “cat's claw”) has become highly popular in many countries due to its proven immunostimmulatory and anti-inflammatory activities and also with respect to its anticancer and antioxidative effects. There are insufficient data on the mechanism of U. tomentosa action on normal blood mononuclear cells. Aim of the study The aim of the study was to analyze the impact of ethanol and aqueous extracts from bark and leaves of Uncaria tomentosa on the structure and function of human mononuclear cells and to find out whether the kind of extractant used modulates biological activity of the extracts studied. Materials and methods Plant material consisted of four different extracts: (1) ethanol extract from leaves, (2) aqueous extract from leaves, (3) ethanol extract from bark and (4) aqueous extract from bark. The effect of these extracts on protein damage as well as on free-radical formation in human peripheral blood mononuclear cells was analyzed. Moreover, changes in viability, size, and granularity as well as apoptotic alterations in human blood mononuclear cells exposed to U. tomentosa extracts were investigated. Results The oxidative changes were observed in mononuclear blood cells exposed to both ethanol and aqueous extracts obtained from bark and leaves. Moreover, in the cells studied the extracts from U. tomentosa induced apoptosis and a decrease in viability of mononuclear blood cells, with the exception of aqueous extract from leaves. Additionally, no statistically significant changes in the cell size were observed both for aqueous extracts from leaves and bark. Changes in the blood mononuclear cell granularity were observed at 250 μg/mL for all extracts examined. The strongest changes were observed for the ethanol extract of the bark, which increased cell granularity at 50 μg/mL and changed cell size at 100 μg/mL. Conclusion The conducted research showed differences in biological activity between aqueous and ethanol extracts. It was observed that ethanol extracts exhibited stronger negative effects on mononuclear blood cells. The kind of extractant used had a significant influence of the chemical composition of the tested extracts. The ethanol extract from bark containing a high amount of polyphenols and alkaloids revealed the highest pro-apoptotic effect.
-
Evaluation of biological activity of Uncaria tomentosa (Willd.) DC. using the chicken embryo model.
Folia biologica, 2009Co-Authors: Radosław Pilarski, Marek Bednarczyk, Krzysztof GulewiczAbstract:The biological activity of Uncaria tomentosa (Willd.) DC. (cat's claw) was evaluated by application of the chicken embryo model. Among three groups of eggs (n = 360) with twelve-day old embryos, two were injected with different doses of cat's claw extracts (0.0492 and 0.492 mg/200 lambda). To the third control group 200 lambda of physiological salt was applied. All eggs were incubated in conventional forced-air apparatus until hatched. Hatchability, chicken weight and wholesomeness were analyzed. Selected parameters of blood including number of erythrocytes (RBC), number of leukocytes (WBC), mean red cell volume (MCV), hematocrit (HCT), hemoglobin concentration (HGB), mean amount of cell hemoglobin (MCH), mean cell hemoglobin concentration (MCHC) and embryo weight (MAS) were assayed and compared. Significant differences with ANOVA were observed for MCV (P = 0.002), MCHC (P = 0.00001) and MCH (P = 0.02). Applying the chicken embryo model brought new information about the biological activity of U. tomentosa showing an unfavourable effect on some morphological blood parameters.
-
Effect of Alkaloid-Free and Alkaloid-Rich preparations from Uncaria tomentosa bark on mitotic activity and chromosome morphology evaluated by Allium Test
Journal of ethnopharmacology, 2008Co-Authors: Mieczysław Kuraś, Radosław Pilarski, Julita Nowakowska, Alicja M. Zobel, Krzysztof Brzost, J. Antosiewicz, Krzysztof GulewiczAbstract:Abstract Ethnopharmacological revelance Uncaria tomentosa (Willd.) DC. is the most popular Peruvian plant, used in folk medicine for different purposes. It contains thousands of active compounds with great content of alkaloids. Aim of study Two different fractions of Alkaloid-Rich and Alkaloid-Free were researched on chromosome morphology, mitotic activity and phases indexes. Materials and methods Cells of Allium Test (meristematic cells of root tips) were incubated up to 24 h in different concentrations of Alkaloid-Free and Alkaloid-Rich fraction obtained from Uncaria tomentosa bark followed by 48 h of postincubation in water. The chromosome morphology was analyzed and the content of mitotic and phase indexes were done. Individual compounds, oxindole alkaloids, phenolic compounds and sugars were determined. Results In Alkaloid-Rich and Alkaloid-Free fractions (different in chemical composition) we observed condensation and contraction of chromosomes (more in Alkaloid-Rich) with retardation and/or inhibition of mitoses and changed mitotic phases. Postincubation reversed results in the highest concentration which was lethal (in mostly Alkaloid-Rich fraction). Conclusions Our studies indicate that different action can depend on different groups of active compounds in a preparation either containing alkaloids or not. Other fraction analysis may be useful in the future.
-
Antiproliferative activity of various Uncaria tomentosa preparations on HL-60 promyelocytic leukemia cells.
Pharmacological reports : PR, 2007Co-Authors: Radosław Pilarski, Magdalena Poczekaj-kostrzewska, Danuta Ciesiołka, Krzysztof Szyfter, Krzysztof GulewiczAbstract:The woody Amazonian vine Uncaria tomentosa (cat's claw) has been recently more and more popular all over the world as an immunomodulatory, antiinflammatory and anti-cancer remedy. This study investigates anti-proliferative potency of several cat's claw preparations with different quantitative and qualitative alkaloid contents on HL-60 acute promyelocytic human cells by applying trypan blue exclusion and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction assay (MTT). By standardization and statistical comparison of the obtained results pteropodine and isomitraphylline are indicated to be most suitable for standardization of medical cat's claw preparations.
-
Antioxidant activity of ethanolic and aqueous extracts of Uncaria tomentosa (Willd.) DC.
Journal of ethnopharmacology, 2005Co-Authors: Radosław Pilarski, Danuta Ciesiołka, Henryk Zieliński, Krzysztof GulewiczAbstract:The antioxidant properties of aqueous and ethanolic extracts of the Uncaria tomentosa bark were evaluated. The analysis included trolox equivalent antioxidant capacity (TEAC), peroxyl radical-trapping capacity (PRTC), superoxide radical scavenging activity (SOD) and quantitation of total tannins (TT) and total phenolic compounds (TPC). The obtained results indicate high antioxidant capacity of the studied materials in comparison to the other extracts of fruits, vegetables, cereals and medicinal plants. Higher antioxidant activity and total phenolic compounds of the alcoholic preparations -- TEAC=0.57 mmol of Trolox/g, PRTC=0.52 mmol of Trolox/g and SOD=0.39 U/mg than of the aqueous preparation -- TEAC=0.34 mmol of Trolox/g, PRTC=0.19 mmol of Trolox/g and SOD=0.10 U/mg were observed. These results might suggest higher medical suitability of alcoholic extracts. However, the highly elevated level of tannins in alcoholic extracts may cause undesirable gastric effects.
Norio Aimi - One of the best experts on this subject based on the ideXlab platform.
-
New oleanan-type triterpene and cincholic acid glycosides from Peruvian "Uña de Gato" (Uncaria tomentosa).
Chemical & pharmaceutical bulletin, 2004Co-Authors: Mariko Kitajima, Norio Aimi, Ken-ichiro Hashimoto, Manuel Sandoval, Hiromitsu TakayamaAbstract:A new oleanan-type triterpene and three new cincholic acid glycosides were isolated from Peruvian "Una de Gato" (Cat's claw, plant of origin: Uncaria tomentosa), a traditional herbal medicine in Peru. Their structures were determined by spectroscopic analysis.
-
Two new nor-triterpene glycosides from peruvian "Uña de Gato" (Uncaria tomentosa).
Journal of natural products, 2003Co-Authors: Mariko Kitajima, Hiromitsu Takayama, Masashi Yokoya, Ken-ichiro Hashimoto, Manuel Sandoval, Norio AimiAbstract:Two new 27-nor-triterpene glycosides, tomentosides A (1) and B (2), were isolated from Peruvian “Una de Gato” (cat's claw, plant of origin: Uncaria tomentosa), a traditional herbal medicine in Peru. Their structures were determined by spectroscopic analysis and chemical interconversions. This is the first report of naturally occurring pyroquinovic acid glycosides.
-
Effects of Uncaria tomentosa total alkaloid and its components on experimental amnesia in mice: elucidation using the passive avoidance test.
Journal of Pharmacy and Pharmacology, 2000Co-Authors: Mohamed A.-f. Abdel-fattah, Kinzo Matsumoto, Keiichi Tabata, Hiromitsu Takayama, Mariko Kitajima, Norio Aimi, Hiroshi WatanabeAbstract:The effects of Uncaria tomentosa total alkaloid and its oxindole alkaloid components, uncarine E, uncarine C, mitraphylline, rhynchophylline and isorhynchophylline, on the impairment of retention performance caused by amnesic drugs were investigated using a step-down-type passive avoidance test in mice. In this test, the retention performance of animals treated with the amnesic and test drugs before training was assessed 24 h after training. Uncaria tomentosa total alkaloid (10-20 mg kg(-1), i.p.) and the alkaloid components (10-40 mg kg(-1), i.p.), as well as the muscarinic receptor agonist oxotremorine (0.01 mg kg(-1), i.p.), significantly attenuated the deficit in retention performance induced by the muscarinic receptor antagonist scopolamine (3 mg kg(-1), i.p.). The effective doses of uncarine C and mitraphylline were larger than those of other alkaloid components. Uncarine E (20 mg kg(-1), i.p.) also blocked the impairment of passive avoidance performance caused by the nicotinic receptor antagonist mecamylamine (15 mg kg(-1), i.p.) and the N-methyl-D-aspartate (NMDA) receptor antagonist (+/-)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP; 7.5 mg kg(-1), i.p.), but it failed to affect the deficit caused by the benzodiazepine receptor agonist diazepam (2 mg kg(-1), i.p.). Rhynchophylline significantly reduced the mecamylamine-induced deficit in passive avoidance behaviour, but it failed to attenuate the effects of CPP and diazepam. These results suggest that Uncaria tomentosa total alkaloids exert a beneficial effect on memory impairment induced by the dysfunction of cholinergic systems in the brain and that the effect of the total alkaloids is partly attributed to the oxindole alkaloids tested. Moreover, these findings raised the possibility that the glutamatergic systems are implicated in the anti-amnesic effect of uncarine E.
-
Two New 19-Hydroxyursolic Acid-type Triterpenes from Peruvian ‘Uña de Gato’ (Uncaria tomentosa)
Tetrahedron, 2000Co-Authors: Mariko Kitajima, Hiromitsu Takayama, Masashi Yokoya, Ken-ichiro Hashimoto, Norio AimiAbstract:Abstract Two new triterpenes having a 19-hydroxyursolic acid skeleton were isolated from ‘Una de Gato’ (Uncaria tomentosa), a traditional herbal medicine in Peru. Their structures were determined by spectroscopic analyses and chemical conversion.
-
A new gluco indole alkaloid, 3, 4-dehydro-5-carboxystrictosidine, from Peruvian Uña de Gato (Uncaria tomentosa).
Chemical & pharmaceutical bulletin, 2000Co-Authors: Mariko Kitajima, Hiromitsu Takayama, Norio Aimi, Masashi Yokoya, Ken-ichiro Hashimoto, Shin-ichiro SakaiAbstract:A new gluco indole alkaloid, 3, 4-dehydro-5-carboxystrictosidine, was obtained from Peruvian Una de Gato(Cat's Claw, original plant : Uncaria tomentosa) together with two known gluco indole alkaloids. This compound was the first example of isolation of a gluco monoterpenoid indole alkaloid having a 3, 4-dihydro-β-carboline ring system from nature. A characteristc feature of the compound was the quick replacement of the methylene hydrogens on C-14 with deuterium that was observed when it was dissolved in CD3OD. We demonstrated a similar proton-deuterium exchange on a model compound, 1-methyl-3, 4-dihydro-β-carboline, in CD3OD solution.
Mariko Kitajima - One of the best experts on this subject based on the ideXlab platform.
-
New oleanan-type triterpene and cincholic acid glycosides from Peruvian "Uña de Gato" (Uncaria tomentosa).
Chemical & pharmaceutical bulletin, 2004Co-Authors: Mariko Kitajima, Norio Aimi, Ken-ichiro Hashimoto, Manuel Sandoval, Hiromitsu TakayamaAbstract:A new oleanan-type triterpene and three new cincholic acid glycosides were isolated from Peruvian "Una de Gato" (Cat's claw, plant of origin: Uncaria tomentosa), a traditional herbal medicine in Peru. Their structures were determined by spectroscopic analysis.
-
Two new nor-triterpene glycosides from peruvian "Uña de Gato" (Uncaria tomentosa).
Journal of natural products, 2003Co-Authors: Mariko Kitajima, Hiromitsu Takayama, Masashi Yokoya, Ken-ichiro Hashimoto, Manuel Sandoval, Norio AimiAbstract:Two new 27-nor-triterpene glycosides, tomentosides A (1) and B (2), were isolated from Peruvian “Una de Gato” (cat's claw, plant of origin: Uncaria tomentosa), a traditional herbal medicine in Peru. Their structures were determined by spectroscopic analysis and chemical interconversions. This is the first report of naturally occurring pyroquinovic acid glycosides.
-
Effects of Uncaria tomentosa total alkaloid and its components on experimental amnesia in mice: elucidation using the passive avoidance test.
Journal of Pharmacy and Pharmacology, 2000Co-Authors: Mohamed A.-f. Abdel-fattah, Kinzo Matsumoto, Keiichi Tabata, Hiromitsu Takayama, Mariko Kitajima, Norio Aimi, Hiroshi WatanabeAbstract:The effects of Uncaria tomentosa total alkaloid and its oxindole alkaloid components, uncarine E, uncarine C, mitraphylline, rhynchophylline and isorhynchophylline, on the impairment of retention performance caused by amnesic drugs were investigated using a step-down-type passive avoidance test in mice. In this test, the retention performance of animals treated with the amnesic and test drugs before training was assessed 24 h after training. Uncaria tomentosa total alkaloid (10-20 mg kg(-1), i.p.) and the alkaloid components (10-40 mg kg(-1), i.p.), as well as the muscarinic receptor agonist oxotremorine (0.01 mg kg(-1), i.p.), significantly attenuated the deficit in retention performance induced by the muscarinic receptor antagonist scopolamine (3 mg kg(-1), i.p.). The effective doses of uncarine C and mitraphylline were larger than those of other alkaloid components. Uncarine E (20 mg kg(-1), i.p.) also blocked the impairment of passive avoidance performance caused by the nicotinic receptor antagonist mecamylamine (15 mg kg(-1), i.p.) and the N-methyl-D-aspartate (NMDA) receptor antagonist (+/-)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP; 7.5 mg kg(-1), i.p.), but it failed to affect the deficit caused by the benzodiazepine receptor agonist diazepam (2 mg kg(-1), i.p.). Rhynchophylline significantly reduced the mecamylamine-induced deficit in passive avoidance behaviour, but it failed to attenuate the effects of CPP and diazepam. These results suggest that Uncaria tomentosa total alkaloids exert a beneficial effect on memory impairment induced by the dysfunction of cholinergic systems in the brain and that the effect of the total alkaloids is partly attributed to the oxindole alkaloids tested. Moreover, these findings raised the possibility that the glutamatergic systems are implicated in the anti-amnesic effect of uncarine E.
-
Two New 19-Hydroxyursolic Acid-type Triterpenes from Peruvian ‘Uña de Gato’ (Uncaria tomentosa)
Tetrahedron, 2000Co-Authors: Mariko Kitajima, Hiromitsu Takayama, Masashi Yokoya, Ken-ichiro Hashimoto, Norio AimiAbstract:Abstract Two new triterpenes having a 19-hydroxyursolic acid skeleton were isolated from ‘Una de Gato’ (Uncaria tomentosa), a traditional herbal medicine in Peru. Their structures were determined by spectroscopic analyses and chemical conversion.
-
A new gluco indole alkaloid, 3, 4-dehydro-5-carboxystrictosidine, from Peruvian Uña de Gato (Uncaria tomentosa).
Chemical & pharmaceutical bulletin, 2000Co-Authors: Mariko Kitajima, Hiromitsu Takayama, Norio Aimi, Masashi Yokoya, Ken-ichiro Hashimoto, Shin-ichiro SakaiAbstract:A new gluco indole alkaloid, 3, 4-dehydro-5-carboxystrictosidine, was obtained from Peruvian Una de Gato(Cat's Claw, original plant : Uncaria tomentosa) together with two known gluco indole alkaloids. This compound was the first example of isolation of a gluco monoterpenoid indole alkaloid having a 3, 4-dihydro-β-carboline ring system from nature. A characteristc feature of the compound was the quick replacement of the methylene hydrogens on C-14 with deuterium that was observed when it was dissolved in CD3OD. We demonstrated a similar proton-deuterium exchange on a model compound, 1-methyl-3, 4-dihydro-β-carboline, in CD3OD solution.
Hiromitsu Takayama - One of the best experts on this subject based on the ideXlab platform.
-
New oleanan-type triterpene and cincholic acid glycosides from Peruvian "Uña de Gato" (Uncaria tomentosa).
Chemical & pharmaceutical bulletin, 2004Co-Authors: Mariko Kitajima, Norio Aimi, Ken-ichiro Hashimoto, Manuel Sandoval, Hiromitsu TakayamaAbstract:A new oleanan-type triterpene and three new cincholic acid glycosides were isolated from Peruvian "Una de Gato" (Cat's claw, plant of origin: Uncaria tomentosa), a traditional herbal medicine in Peru. Their structures were determined by spectroscopic analysis.
-
Two new nor-triterpene glycosides from peruvian "Uña de Gato" (Uncaria tomentosa).
Journal of natural products, 2003Co-Authors: Mariko Kitajima, Hiromitsu Takayama, Masashi Yokoya, Ken-ichiro Hashimoto, Manuel Sandoval, Norio AimiAbstract:Two new 27-nor-triterpene glycosides, tomentosides A (1) and B (2), were isolated from Peruvian “Una de Gato” (cat's claw, plant of origin: Uncaria tomentosa), a traditional herbal medicine in Peru. Their structures were determined by spectroscopic analysis and chemical interconversions. This is the first report of naturally occurring pyroquinovic acid glycosides.
-
Effects of Uncaria tomentosa total alkaloid and its components on experimental amnesia in mice: elucidation using the passive avoidance test.
Journal of Pharmacy and Pharmacology, 2000Co-Authors: Mohamed A.-f. Abdel-fattah, Kinzo Matsumoto, Keiichi Tabata, Hiromitsu Takayama, Mariko Kitajima, Norio Aimi, Hiroshi WatanabeAbstract:The effects of Uncaria tomentosa total alkaloid and its oxindole alkaloid components, uncarine E, uncarine C, mitraphylline, rhynchophylline and isorhynchophylline, on the impairment of retention performance caused by amnesic drugs were investigated using a step-down-type passive avoidance test in mice. In this test, the retention performance of animals treated with the amnesic and test drugs before training was assessed 24 h after training. Uncaria tomentosa total alkaloid (10-20 mg kg(-1), i.p.) and the alkaloid components (10-40 mg kg(-1), i.p.), as well as the muscarinic receptor agonist oxotremorine (0.01 mg kg(-1), i.p.), significantly attenuated the deficit in retention performance induced by the muscarinic receptor antagonist scopolamine (3 mg kg(-1), i.p.). The effective doses of uncarine C and mitraphylline were larger than those of other alkaloid components. Uncarine E (20 mg kg(-1), i.p.) also blocked the impairment of passive avoidance performance caused by the nicotinic receptor antagonist mecamylamine (15 mg kg(-1), i.p.) and the N-methyl-D-aspartate (NMDA) receptor antagonist (+/-)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP; 7.5 mg kg(-1), i.p.), but it failed to affect the deficit caused by the benzodiazepine receptor agonist diazepam (2 mg kg(-1), i.p.). Rhynchophylline significantly reduced the mecamylamine-induced deficit in passive avoidance behaviour, but it failed to attenuate the effects of CPP and diazepam. These results suggest that Uncaria tomentosa total alkaloids exert a beneficial effect on memory impairment induced by the dysfunction of cholinergic systems in the brain and that the effect of the total alkaloids is partly attributed to the oxindole alkaloids tested. Moreover, these findings raised the possibility that the glutamatergic systems are implicated in the anti-amnesic effect of uncarine E.
-
Two New 19-Hydroxyursolic Acid-type Triterpenes from Peruvian ‘Uña de Gato’ (Uncaria tomentosa)
Tetrahedron, 2000Co-Authors: Mariko Kitajima, Hiromitsu Takayama, Masashi Yokoya, Ken-ichiro Hashimoto, Norio AimiAbstract:Abstract Two new triterpenes having a 19-hydroxyursolic acid skeleton were isolated from ‘Una de Gato’ (Uncaria tomentosa), a traditional herbal medicine in Peru. Their structures were determined by spectroscopic analyses and chemical conversion.
-
A new gluco indole alkaloid, 3, 4-dehydro-5-carboxystrictosidine, from Peruvian Uña de Gato (Uncaria tomentosa).
Chemical & pharmaceutical bulletin, 2000Co-Authors: Mariko Kitajima, Hiromitsu Takayama, Norio Aimi, Masashi Yokoya, Ken-ichiro Hashimoto, Shin-ichiro SakaiAbstract:A new gluco indole alkaloid, 3, 4-dehydro-5-carboxystrictosidine, was obtained from Peruvian Una de Gato(Cat's Claw, original plant : Uncaria tomentosa) together with two known gluco indole alkaloids. This compound was the first example of isolation of a gluco monoterpenoid indole alkaloid having a 3, 4-dihydro-β-carboline ring system from nature. A characteristc feature of the compound was the quick replacement of the methylene hydrogens on C-14 with deuterium that was observed when it was dissolved in CD3OD. We demonstrated a similar proton-deuterium exchange on a model compound, 1-methyl-3, 4-dihydro-β-carboline, in CD3OD solution.
