-
[show abstract]
[hide abstract]
ABSTRACT: Saponins, plant glycosides, have been reported to possess anti-cancer properties. Therefore the effect of corchorusin-D (COR-D), a compound isolated from Corchorus acutangulus, was studied in the chronic myelogenous leukemic cell line K562, using MTT assay, phase contrast and confocal microscopy, annexin V binding, cell cycle analysis and western blotting. COR-D inhibited cell growth in K562 cells and showed increased number of Annexin V FITC binding cells. Characteristic apoptotic changes, seen under phase contrast and confocal microscopes with accumulation of cells in the sub-G0 phase. The apoptosis involved drop in Bcl-2/Bax ratio, loss of mitochondrial membrane potential, release of cytochrome c in cytosol followed by activation of caspases 9 and 3, and cleavage of PARP. Down-regulation of pro-caspase 10 was observed along with formation of death-inducing signaling complex between TNF-R1 and TRADD. COR-D suppressed PDK1 and AKT with activation of MAP kinase family members ERK1/2, JNK1/2 and p38. Thus it induced apoptosis by activating mitochondrial and death receptor pathways and suppressing AKT/PKB rather than MAP kinase pathway. Significant enhancement of apoptosis, noted using specific inhibitors of ERK1/2, p38 and JNK1/2, suggests that COR-D can enhance apoptosis in K562 cells in combination with MAP kinase inhibitors.
Cellular Physiology and Biochemistry 09/2012; 30(4):915-926. · 2.86 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Eclipta alba (L.) Hassk is used traditionally in diabetes mellitus in India and the plant extract is reported to possess anti-diabetic activity. A bioactivity-guided isolation approach based on alpha-glucosidase inhibition was used to identify the constituents contributing towards the inhibition of the enzyme and probably contributing towards its anti-diabetic activity. Four echinocystic acid glycosides were thus isolated, of which eclalbasaponin VI, isolated from the n-butanol fraction, was found to be the most potent (IC50 54.2 +/- 1.3 microM). The compound is an uncompetitive type of inhibitor with Ki 26.1 microM. A quantitative estimation of the constituents was established using RP-HPLC.
Natural product communications 08/2012; 7(8):989-90. · 1.24 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The increasing demand for natural-product-based medicines and health-care products for the management of diabetes encouraged investigation of this commonly available Indian plant.
To establish the anti-diabetic (α-glucosidase inhibitory) activity of H. mutabilis leaf extract, isolate and identify the constituents responsible for the activity, and validate a HPLC method for quantification of the active constituents for standardisation of the extract.
The methanolic extract of leaves was partitioned between water, n-butanol and ethyl acetate. Bio-assay guided fractionation, based on inhibition of α-glucosidase, allowed isolation and identification of the active components. The active components were quantified using RP-HPLC-DAD validated for linearity, limit of detection, limit of quantification, precision, accuracy and robustness for this plant extract and the partitioned fractions.
Ferulic acid and caffeic acid were identified as the α-glucosidase inhibitors present in H. mutabilis. They were partitioned into an ethyl acetate fraction. The HPLC-DAD calibration curve showed good linearity (r² > 0.99). For the recovery studies the %RSD was less than 2%. The interday and intraday variations were found to be less than 4% RSD for retention time and response.
The identification of α-glucosidase inhibition activity in H. mutabilis supports further investigations into the possible use of the plant for the management of diabetes. The HPLC method validated for these extracts will be useful in future research with the plant.
Phytochemical Analysis 12/2011; 23(5):421-5. · 2.63 Impact Factor
-
Jayashree B Chakraborty,
Sanjit K Mahato,
Kalpana Joshi,
Vaibhav Shinde,
Srabanti Rakshit,
Nabendu Biswas,
Indrani Choudhury Mukherjee,
Labanya Mandal,
Dipyaman Ganguly,
Avik A Chowdhury, [......],
Kausik Paul, Bikas C Pal,
Jayaraman Vinayagam,
Churala Pal,
Anirban Manna,
Parasuraman Jaisankar,
Utpal Chaudhuri,
Aditya Konar,
Siddhartha Roy,
Santu Bandyopadhyay
[show abstract]
[hide abstract]
ABSTRACT: Alcoholic extract of Piper betle (Piper betle L.) leaves was recently found to induce apoptosis of CML cells expressing wild type and mutated Bcr-Abl with imatinib resistance phenotype. Hydroxy-chavicol (HCH), a constituent of the alcoholic extract of Piper betle leaves, was evaluated for anti-CML activity. Here, we report that HCH and its analogues induce killing of primary cells in CML patients and leukemic cell lines expressing wild type and mutated Bcr-Abl, including the T315I mutation, with minimal toxicity to normal human peripheral blood mononuclear cells. HCH causes early but transient increase of mitochondria-derived reactive oxygen species. Reactive oxygen species-dependent persistent activation of JNK leads to an increase in endothelial nitric oxide synthase-mediated nitric oxide generation. This causes loss of mitochondrial membrane potential, release of cytochrome c from mitochondria, cleavage of caspase 9, 3 and poly-adenosine diphosphate-ribose polymerase leading to apoptosis. One HCH analogue was also effective in vivo in SCID mice against grafts expressing the T315I mutation, although to a lesser extent than grafts expressing wild type Bcr-Abl, without showing significant bodyweight loss. Our data describe the role of JNK-dependent endothelial nitric oxide synthase-mediated nitric oxide for anti-CML activity of HCH and this molecule merits further testing in pre-clinical and clinical settings.
Cancer Science 09/2011; 103(1):88-99. · 3.33 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Accumulation of bilirubin, primarily because of its insolubility, has been found to be associated with liver diseases including jaundice. Free bilirubin is insoluble; its glucuronidation by bilirubin-UGT enzyme (UGT1A1) makes it soluble and eliminates it through urine and faeces. Taking CCl(4) induced rat liver dysfunction model, we demonstrated that suppression of UGT1A1 activity in rat liver increased serum bilirubin level which could be reversed by carlinoside (Cln), a flavone glycoside. Although Cln is a flavone compound, it escaped self-glucuronidation in the intestine and readily absorbed. Kinetic study of microsomal UGT1A1 from HepG2 cells suggested that Cln enhanced enzyme activity by increasing V(max) without altering K(m). This altered V(max) was found to be due to UGT1A1 overexpression by Cln which was observed in both HepG2 and rat primary hepatocytes. Since Nrf2 is the transcription factor of UGT1A1, we examined whether Cln effect on UGT1A1 overexpression is mediated through Nrf2. In Nrf2 knock-out cells, Cln could not elevate UGT1A1 activity indicating Nrf2 to be its target. Cln significantly increased Nrf2 gene expression in HepG2 cells which was subsequently localized in nuclear region. Results from ChIP assay showed that Cln markedly augmented Nrf2 binding to UGT1A1 promoter that consequently enhanced reporter activity. Our findings therefore show that Cln upregulated Nrf2 gene expression, increased its nuclear translocation and stimulated UGT1A1 promoter activity. Total outcome of these events brought about a significant increase of bilirubin glucuronidation. Cln therefore could be a worthy choice to intervene hyperbilirubinemia due to liver dysfunction.
Biochemical pharmacology 07/2011; 82(9):1186-97. · 4.25 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Baliospermum montanum leaves yielded 3-hydroxy-2,4-dimethoxy-10-methyl-9-acridanone (1), an alkaloid from the CHCl₃ fraction. Spectroscopic analysis was performed to assign the structure of the new compound (1) and its absolute configuration. The compound was evaluated for its effect in anaphylaxis by estimation of the release of histamine in systemic anaphylaxis model. The acridanone alkaloid significantly inhibited the degranulation of mast cells up to 65.22 % and 75.12 % at a dose of 50 and 75 mg/kg, respectively.
Planta Medica 06/2011; 77(17):1947-9. · 2.15 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The presence of triterpene saponins in Corchorus acutangulus Lam. has been reported. However, no studies concerning biological activity of the plant extracts have been done so far. In the present study, the anti-leukemic activity of the methanol extract of aerial parts (ME) of C. acutangulus has been investigated, and efforts have been made to identify the active ingredient responsible for this activity.
The anti-leukemic activity of ME, its fractions and corchorusin-D (COR-D), the active ingredient, was investigated in leukemic cell lines U937 and HL-60 using cell viability and MTT assays. The molecular pathways leading to the activity of COR-D were examined by confocal microscopy, flow-cytometry, caspase and Western blot assays.
ME, its n-butanolic fraction and COR-D inhibited cell growth and produced significant cytotoxicity in leukemic cell lines U937 and HL-60. COR-D produced apoptotic cell death via mitochondrial disfunction and was found to pursue the intrinsic pathway by inciting the release of apoptosis-inducing factors (AIFs) from mitochondria. COR-D-induced translocation of Bax from cytosol to mitochondria facilitating caspase-9 activation and up regulation of downstream pathways leading to caspase-3 activation and PARP cleavage, which resulted in the subsequent accumulation of cells in the sub-G0 phase followed by DNA fragmentation.
COR-D possesses significant anti-leukemic activity in U937 and HL-60 cell lines by acting on the mitochondrial apoptotic pathways. Since the necrotic body formation is low after COR-D treatment, the occurrence of inflammation in in vivo systems could be reduced, which represents a positive indication in view of therapeutic application.
Cancer Chemotherapy and Pharmacology 09/2010; 66(4):709-19. · 2.83 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The methanolic extract of Dillenia indica L. fruits showed significant anti-leukemic activity in human leukemic cell lines U937, HL60 and K562. This finding led to fractionation of the methanolic extract, on the basis of polarity, in which the ethyl acetate fraction showed the highest anti-leukemic activity. A major compound, betulinic acid, was isolated from the ethyl acetate fraction by silica gel column chromatography and was identified and characterized. Betulinic acid could explain the anti-leukemic activity of the methanolic extract and the ethyl acetate fraction. Hence the quantitative estimation of betulinic acid was approached in methanolic extract and fractions using HPLC.
Phytomedicine: international journal of phytotherapy and phytopharmacology 09/2009; 17(6):431-5. · 2.17 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Apo-1 (Fas/CD95), a cell surface receptor, triggers apoptosis after binding to its physiological ligand, Apo-1L (FasL/CD95L). This study reports that mahanine, purified from the leaves of Murraya koenigii, has a dose- and time-dependent anti-proliferative activity in acute lymphoid (MOLT-3) and chronic myeloid (K562) leukemic cell lines and in the primary cells of leukemic and myeloid patients, with minimal effect on normal immune cells including CD34(+) cells. Leukemic cells underwent phosphatidylserine externalization and DNA fragmentation, indicating mahanine-induced apoptosis. An increase in reactive oxygen species suggests that the mahanine-induced apoptosis was mediated by oxidative stress. A significant drop in the Bcl2/Bax ratio, the loss of mitochondrial transmembrane potential as well as cytochrome c release from the mitochondria to the cytosol suggested involvement of the mitochondrial pathway of apoptosis. Cytochrome c release was followed by the activation of caspase-9, caspase-3 and caspase-7, and cleavage of PARP in both MOLT-3 and K562 cells. In MOLT-3 cells, formation of the Fas-FasL-FADD-caspase-8 heterotetramer occurred, leading to the cleavage of Bid to its truncated form, which consequently resulted in formation of the mitochondrial transmembrane pore. The incubation of MOLT-3 cells with mahanine in the presence of caspase-8 inhibitor or FasL-neutralizing NOK-2 antibody resulted in the decrease of mahanine-induced cell death. Mahanine was also a potent inhibitor of K562 xenograft growth, which was evident in an athymic nude mice model. In summary, these results provide evidence for involvement of the death receptor-mediated extrinsic pathway of apoptosis in the mahanine-induced anticancer activity in MOLT-3 cells, but not in K562 cells, which are deficient in Fas/FasL.
Biochemical pharmacology 09/2009; 79(3):361-72. · 4.25 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Cajanus cajan Linn. (Leguminosae) is a nontoxic edible herb, widely used in Indian folk medicine for the prevention of various liver disorders. In the present study we have demonstrated that methanol-aqueous fraction (MAF2) of Cajanus cajan leaf extract could prevent the chronically treated alcohol induced rat liver damage.
Chronic doses of alcohol (3.7 g/ kg) orally administered to rats for 28 days and liver function marker enzymes such as GPT, GOT, ALP and anti-oxidant enzyme activities were determined. Effect of MAF2 at a dose of 50mg/kg body weight on alcohol treated rats was noted.
Alcohol effected significant increase in liver marker enzyme activities and reduced the activities of anti-oxidant enzymes. Co-administration of MAF2 reversed the liver damage due to alcohol; it decreased the activities of liver marker enzymes and augmented antioxidant enzyme activities. We also demonstrate significant decrease of the phase II detoxifying enzyme, UDP-glucuronosyl transferase (UGT) activity along with a three- and two-fold decrease of UGT2B gene and protein expression respectively. MAF2 co-administration normalized UGT activity and revived the expression of UGT2B with a concomitant expression and nuclear translocation of Nrf2, a transcription factor that regulates the expression of many cytoprotective genes.
Cajanus cajan extract therefore shows a promise in therapeutic use in alcohol induced liver dysfunction.
Journal of Ethnopharmacology 06/2008; 118(3):440-7. · 3.01 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: It is becoming clear that frequent epigenetic silencing of tumor suppressor genes could be responsible for the development of cancer in various organs. Several recent reports suggest that suppression of RASSF1A is associated with the advanced grade and stage of prostate cancer and many other cancers. In this investigation, we demonstrated that, mahanine, a plant derived carbazole alkaloid, induced RASSF1A expression in both androgen-responsive (LNCaP) and androgen-negative (PC3) prostate cancer cells by inhibiting DNA methyltransferase (DNMT) activity. Mahanine-induced expression of RASSF1A in turn significantly reduced cyclin D1 but not other cyclins. To understand the inverse relationship between RASSF1A and cyclin D1, we observed that mahanine treatment down-regulates cyclin D1 and addition of RASSF1A siRNA prevented this inhibition. This study show for the first time that mahanine can reverse an epigenetically silenced gene, RASSF1A in prostate cancer cells by inhibiting DNMT activity that in turn down-regulates a key cell cycle regulator, cyclin D1. Mahanine therefore, promises an encouraging therapeutic choice for advanced prostatic cancer.
Biochemical and Biophysical Research Communications 11/2007; 362(1):212-7. · 2.48 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: The present study was undertaken to evaluate anti-proliferative and -apoptotic activities of mahanine, a plant derived carbazole alkaloid, in prostate cancer cells and to determine its molecular mechanism by which it induces apoptotic cell death.
The growth inhibitory and apoptotic inductive effect of mahanine on prostate cancer cells were examined by measuring cell proliferation and BrdU labeling, caspase activity, DNA fragmentation, and Western blot analyses.
Mahanine inhibited growth of PC3 and LNCaP prostate cancer cells in a dose and time-dependent manner. Mechanistically, mahanine inhibited cell-survival pathway by dephosphorylation of PIP3 dependent kinase 1 (PDK1) thereby deactivation of Akt and downregulation of Bcl-xL. In addition, mahanine activated caspase pathway (caspases 9 and 3) and eventually cleavage of DNA repair enzyme, PARP resulting DNA fragmentation and apoptosis.
Mahanine inhibits growth and induces apoptosis in both androgen-responsive, LNCaP and androgen-independent, PC3 cells by targeting cell survival pathway.
The Prostate 10/2006; 66(12):1257-65. · 3.48 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: From the rhizomes of Curculigo orchioides two phenolic glucosides named orchiosides A and B were isolated besides four known compounds and their structures were elucidated by the combination of 2D-NMR analysis, mass spectrometry and chemical evidences.
Phytochemistry 04/2005; 66(6):659-63. · 3.35 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: Seven hopane-type saponins were isolated from the methanol extract of Glinus lotoides. Six of them were identified as novel compounds and designated as lotoideside A [3-O-beta-D-xylopyranosyl (1-->2)-alpha-L-rhamnopyranosyl-6 alpha-O-beta-D-xylopyranosyl-22-beta-O-beta-D-glucopyranosyl-16 beta-hydroxy hopane (1)], lotoideside B [3-O-beta-D-xylopyranosyl (1-->2)-alpha-L-rhamnopyranosyl-22-beta-O-beta-D-glucopyranosyl-6 alpha,16 beta-dihydroxyhopane (2)], lotoideside C [3-OD-xylopyranosyl-6 alpha-O-beta-D-xylopyranosyl-16 beta-O-beta-D-xylopyranosyl-22 beta-hydroxyhopane (3)], lotoideside D [3-O-beta-D-xylopyranosyl-16 beta-O-alpha-L-arabinopyranosyl-6 alpha,22-beta-dihydroxyhopane (4)], lotoideside E [3-O-beta-D-xylopyranosyl-6 alpha-O-beta-D-xylopyranosyl-16 beta,22-beta-dihydroxyhopane (5)], and lotoideside F [3-O-beta-D-xylopyranosyl-22-beta-O-beta-D-glucopyranosyl-16 beta-hydroxyhopan-6-one (6)]. The known compound succulentoside B (7) was also encountered. Their structures were elucidated on the basis of one-and two-dimensional NMR spectroscopic techniques, ESIMS and chemical evidences.
Phytochemistry 04/2005; 66(6):621-6. · 3.35 Impact Factor
-
Gautam Bandyopadhyay,
Tanusree Biswas,
Keshab C Roy,
Swapan Mandal,
Chhabinath Mandal, Bikas C Pal,
Samir Bhattacharya,
Srabanti Rakshit,
Dilip K Bhattacharya,
Utpal Chaudhuri,
Aditya Konar,
Santu Bandyopadhyay
[show abstract]
[hide abstract]
ABSTRACT: We report that chlorogenic acid (Chl) induces apoptosis of several Bcr-Abl-positive chronic myelogenous leukemia (CML) cell lines and primary cells from CML patients in vitro and destroys Bcr-Abl-positive K562 cells in vivo. In contrast, this compound has no effect on the growth and viability of Bcr-Abl-negative lymphocytic and myeloid cell lines and primary CML cells. Sodium chlorogenate (NaChl) exhibits 2-fold higher efficiency in killing K562 cells compared with Chl. NaChl also induces growth inhibition of squamous cell carcinoma (HSC-2) and salivary gland tumor cells (HSG), although at 50-fold higher concentration. NaChl inhibits autophosphorylation of p210(Bcr-Abl) fusion protein rapidly. We demonstrate that p38 phosphorylation is increased in Bcr-Abl-positive cells after treatment with NaChl and closely paralleled the inhibition of Bcr-Abl phosphorylation. NaChl did not increase phosphorylation of p38 in Bcr-Abl-negative cells including HSC-2 and HSG that are responsive to this compound, indicating that p38 activation by NaChl is dependent on Bcr-Abl kinase inhibition. Inhibition of p38 activity by SB203580 significantly reduced NaChl-induced apoptosis of K562 cells, whereas activation of p38 by anisomycin augmented the apoptosis. These findings indicate that inhibition of Bcr-Abl kinase leading to activation of p38 mitogen-activated protein (MAP) kinase may play an important role in the anti-CML activity of Chl.
Blood 11/2004; 104(8):2514-22. · 9.90 Impact Factor
