A novel synthetic oleanolic acid derivative with amino acid conjugate suppresses tumour growth by inducing cell cycle arrest.
ABSTRACT Oleanolic acid (3beta-hydroxy-olean-12-en-28-oic acid; OA) has a wide variety of bioactivities and is used for medicinal purposes in many Asian countries. Various derivatives of OA have been synthesized in attempts to improve the potency. Here we describe the anti-tumour activity of a novel OA derivative, N-[(3beta)-3-(acetyloxy)-28-oxoolean-12-en-28-yl]-glycine methyl ester (AOA-GMe). AOAGMe was a more potent inhibitor of the growth of B16 melanoma cells than its parent compound OA, both in-vitro and in-vivo. AOA-GMe also exhibited dose-dependent inhibition of human K562 leukaemia cells, but had almost no toxicity in normal human peripheral blood mononuclear cells. AOA-GMe induced cell cycle arrest in G0/G1 and blocked G1-S transition, which correlated well with marked decreases in levels of cyclin D, cyclin-dependent kinase CDK4 and phosphorylated retinoblastoma protein, and increases in the cyclin-dependent kinase inhibitor p15. OA did not show such activities. These results suggest that AOA-GMe may induce growth arrest in tumour cells through regulation of proteins involved in the cell cycle.
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ABSTRACT: Oleanolic acid (3β-hydroxy-olea-12-en-28-oic acid) is a natural pentacyclic triterpenoic acid found in many fruits, herbs and medicinal plants. In the past decade, increasing evidence has suggested that oleanolic acid exhibits inhibitory activities against different types of cancer including skin cancer and colon cancer, but not leukemia. We report here that a derivative of oleanolic acid, olean-12-eno[2,3-c] , , oxadiazol-28-oic acid (designated OEOA) effectively blocks the proliferation of human leukemia cells. OEOA significantly reduces cell proliferation without inducing cell death in three types of leukemia cell lines, including K562, HEL and Jurket. Moreover, exposure of K562 cells to OEOA results in G1 cell cycle arrest, with a concomitant induction of cyclin-dependent kinase inhibitor p27 and downregulation of cyclins and Cdks that are essential for cell cycle progression. Interestingly, OEOA also enhances erythroid differentiation in K562 cells through suppressing the expression of Bcr-Abl and phosphorylation of Erk1/2. These findings identify a novel chemical entity for further development as therapeutics against leukemia.PLoS ONE 01/2013; 8(5):e63580. · 3.73 Impact Factor
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ABSTRACT: Several novel esters and amides of maslinic acid were prepared. Their evaluation for cytotoxic activity with a panel of human cancer cell lines using a sulforhodamine B (SRB) assay revealed for some of them a noteworthy activity. The results from annexinV-FITC and caspase-assays as well as from DNA laddering experiments provided evidence for an apoptotic cell death. A diacetylated benzylamide (15) induced a G1/G0 arrest in tumor cells. It also displayed an extraordinary cytotoxicity against human ovarian cancer cells but a 300 times lower toxicity for non-malignant primary human fibroblasts.Bioorganic & medicinal chemistry 11/2013; · 2.82 Impact Factor
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ABSTRACT: Oleanolic acid (3 β -hydroxy-olean-12-en-28-oic acid; OA-01), a pentacyclic triterpene, exhibit a wide range of pharmacological ad biological activities. We have isolated oleanolic acid from methanolic extract of Periploca aphylla, collected from surroundings of Karachi in the month of February. Furthermore, four known and two new C-28 amino acid conjugates of oleanolic acid were prepared to explore potential of these compounds on HCCs and one breast cancer cell line. Cytotoxic effects revealed that as compare to parent compound (OA-01), two derivatives OA-04 (p<0.0001) and OA-06 (p<0.01) showed significantly increased /higher inhibition rates.Pakistan journal of pharmaceutical sciences 09/2014; 27(5):1491. · 0.95 Impact Factor