Folic Acid-Doxorubicin-Double-Functionalized-Lipid-Core Nanocapsules: Synthesis, Chemical Structure Elucidation, and Cytotoxicity Evaluation on Ovarian (OVCAR-3) and Bladder (T24) Cancer Cell Lines.

PURPOSE: Folic acid-doxorubicin-double-functionalized-lipid-core nanocapsules (LNC-CS-L-Zn+2-DOX-FA) were prepared, characterized, and evaluated in vitro against ovarian and bladder cancer cell lines (OVCAR-3 and T24). METHODS: LNC-CS-L-Zn+2-DOX-FA was prepared by self-assembly and interfacial reactions, and characterized using liquid chromatography, particle sizing, transmission electron microscopy, and infrared spectroscopy. Cell viability and cellular uptake were studied using MTT assay and confocal microscopy. RESULTS: The presence of lecithin allows the formation of nanocapsules with a lower tendency of agglomeration, narrower size distributions, and smaller diameters due to an increase in hydrogen bonds at the surface. LNC-L-CS-Zn+2-DOX-FA, containing 98.00 ± 2.34 µg mL-1 of DOX and 105.00 ± 2.05 µg mL-1 of FA, had a mean diameter of 123 ± 4 nm and zeta potential of +12.0 ± 1.3 mV. After treatment with LNC-L-CS-Zn+2-DOX-FA (15 µmol L-1 of DOX), T24 cells had inhibition rates above 80% (24 h) and 90% (48 h), whereas OVCAR-3 cells showed inhibition rates of 68% (24 h) and 93% (48 h), showing higher cytotoxicity than DOX.HCl. The fluorescent-labeled formulation showed a higher capacity of internalization in OVCAR-3 compared to T24 cancer cells. CONCLUSION: Lecithin favored the increase of hydrogen bonds at the surface, leading to a lower tendency of agglomeration for nanocapsules. LNC-CS-L-Zn+2-DOX-FA is a promising therapeutic agent against tumor-overexpressing folate receptors.

Targeting multidrug-resistant ovarian cancer through estrogen receptor α dependent ATP depletion caused by hyperactivation of the unfolded protein response.

Ovarian cancers often recur and tumors acquire resistance to chemotherapy due to overexpression of the ATP-dependent efflux pump, multidrug resistance protein 1 (MDR1/P-glycoprotein/ABCB1). Nontoxic small molecule inhibitors targeting MDR1 have remained largely elusive. Instead, in a novel application of our recently described estrogen receptor α (ERα) biomodulator, BHPI, we targeted MDR1's substrate, ATP. BHPI depletes intracellular ATP and nearly blocks MDR1-mediated drug efflux in ovarian cancer cells by inducing toxic hyperactivation of the endoplasmic reticulum stress sensor, the unfolded protein response (UPR). BHPI increased sensitivity of MDR1 overexpressing multidrug resistant OVCAR-3 ovarian cancer cells to killing by paclitaxel by >1,000 fold. BHPI also restored doxorubicin sensitivity in OVCAR-3 cells and in MDR1 overexpressing breast cancer cells. In an orthotopic OVCAR-3 xenograft model, paclitaxel was ineffective and the paclitaxel-treated group was uniquely prone to form large secondary tumors in adjacent tissue. BHPI alone strongly reduced tumor growth. Notably, tumors were undetectable in mice treated with BHPI plus paclitaxel. Compared to control ovarian tumors, after the combination therapy, levels of the plasma ovarian cancer biomarker CA125 were at least several hundred folds lower; moreover, CA125 levels progressively declined to undetectable. Targeting MDR1 through UPR-dependent ATP depletion represents a promising therapeutic strategy.

Antioxidant, anti-inflammatory, antiproliferative and antimycobacterial activities of the essential oil of Psidium guineense Sw. and spathulenol.

ETHNOPHARMACOLOGICAL RELEVANCE: Leaves from Psidium guineense Sw. are used in popular medicine for the treatment of inflammatory disease. However, there is no scientific evidence demonstrating this activity. AIM OF THE STUDY: To evaluate the antioxidant, anti-inflammatory, antiproliferative and antimycobacterial activities of the essential oil of P. guineense and spathulenol (a major constituent). The study was conducted in part to provide evidence supporting the ethnobotanical use of the leaves of this species. MATERIAL AND METHODS: The essential oil (EOPG) was extracted from the leaves of P. guineense by hydrodistillation and analysed by gas chromatography-mass spectrometry (GC-MS). The major compound, spathulenol (PG-1), was isolated in a chromatographic column and characterized by nuclear magnetic resonance (NMR). EOPG and PG-1 were evaluated in vitro for antioxidant activity by DPPH, ABTS and MDA methods; anti-inflammatory potential was assessed using two models, including pleurisy and oedema, in mice. The impact of EOPG and PG-1 on cell proliferation was determined via spectrophotometric quantification of the cellular protein content using a sulforhodamine B assay, and anti-Mycobacterium tuberculosis activity was determined using the REMA method. RESULTS: A total of 38 components were identified from the EOPG, with the sesquiterpenic alcohol spathulenol (PG-1) (80.7%) being the major constituent. EOPG and PG-1 exhibited the highest antioxidant activities in the DPPH and MDA system compared with reference standard, with IC50 values ranging from 26.13 to 85.60µg/mL. Oral administration of EOPG and PG-1 showed significant inhibition in the Cg-induced mice paw oedema and pleurisy model. The EOPG (GI50 = 0.89µg/mL) and PG-1 (GI50 = 49.30µg/mL) were particularly effective against the ovarian cancer cell line. Both showed moderate antimycobacterial activity. CONCLUSION: For the first time, this study demonstrated the antioxidant, anti-inflammatory, antiproliferative and antimycobacterial properties of the essential oil of P. guineense (leaves were collected in Dourados-MS) and spathulenol, collaborating the etnhopharmacologycal use of this plant due to its an anti-inflammatory effect.