Rocha TGR, Lopes SCDA, Cassali GD, Ferreira Ê, Veloso ES, Leite EA, Braga FC, Ferreira LAM, Balvay D, Garofalakis A, Oliveira MC, Tavitian B. Evaluation of Antitumor Activity of Long-Circulating and pH-Sensitive Liposomes Containing Ursolic Acid in Animal Models of Breast Tumor and Gliosarcoma.
Integr Cancer Ther 2016;
15:512-524. [PMID:
27130721 PMCID:
PMC5739155 DOI:
10.1177/1534735416628273]
[Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2015] [Revised: 12/01/2015] [Accepted: 12/11/2015] [Indexed: 01/05/2023] Open
Abstract
Background Ursolic acid (UA) is a triterpene found in different plant species, possessing antitumor activity, which may be a result of its antiangiogenic effect. However, UA has low water solubility, which limits its use because the bioavailability is impaired. To overcome this inconvenience, we developed long-circulating and pH-sensitive liposomes containing ursolic acid (SpHL-UA). We investigated the antiangiogenic effect of free UA and SpHL-UA in murine brain cancer and human breast tumor models by means of determination of the relative tumor volume, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), and histopathological analysis. Methods The animals were treated with dimethyl sulfoxide in 0.9% (w/v) NaCl, free UA, long-circulating and pH-sensitive liposomes without drug (SpHL), or SpHL-UA. The animals were submitted to each treatment by intraperitoneal injection for 5 days. The dose of free UA or SpHL-UA was equal to 23 mg/kg. Results Tumor growth inhibition was not observed in human breast tumor-bearing animals. For murine gliosarcoma-bearing animals, a slight tumor growth inhibition was observed in the groups treated with free UA or SpHL-UA (9% and 15%, respectively). No significant change in any of the parameters evaluated by DCE-MRI for both experimental models could be observed. Nevertheless, the evaluation of the mean values of magnetic resonance parameters of human breast tumor-bearing animals showed evidence of a possible antiangiogenic effect induced by SpHL-UA. Histopathological analysis did not present significant change for any treatment. Conclusion SpHL-UA did not show antiangiogenic activity in a gliosarcoma model and seemed to induce an antiangiogenic effect in the human breast tumor model.
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