Radioprotective activity of curcumin-encapsulated liposomes against genotoxicity caused by Gamma Cobalt-60 irradiation in human blood cells

<p><b>Purpose:</b> While the radioprotective activity of curcumin against genotoxicity has been well established, its poor oral bioavailability has limited its successful clinical applications. Nanoscale formulations, including liposomes, have been demonstrated to improve curcumin bioavailability. The objective of the present work was (1) to prepare and characterize curcumin-encapsulated liposomes (i.e. size, colloidal stability, encapsulation efficiency, and payload), and (2) subsequently to evaluate their radioprotective activity against genotoxicity in human blood cells caused by Gamma Cobalt-60 irradiation.</p> <p><b>Materials and methods:</b> The curcumin-encapsulated liposomes were prepared by lipid-film hydration method using commercial phosphatidylcholine (i.e. Phospholipon^® 90G). The blood cells were obtained from healthy male donors (<i>n</i> = 3) under an approved ethics protocol. The cell uptake and the radioprotective activity of the curcumin-encapsulated liposomes were characterized by fluorescence microscopy and micronucleus assay, respectively.</p> <p><b>Results:</b> Nanoscale curcumin-encapsulated liposomes exhibiting good physical characteristics and successful uptake by the human blood cells were successfully prepared. The radioprotective activity of the curcumin-encapsulated liposomes was found to be dependent on the curcumin concentration, where an optimal concentration existed (i.e. 30 μg/mL) independent of the irradiation dose, above which the radioprotective activity had become stagnant (i.e. no more reduction in the micronuclei frequency).</p> <p><b>Conclusions:</b> The present results established for the first time the radioprotective activity of curcumin-encapsulated liposomes in human blood cells, which coupled by its well-established bioavailability, boded well for its potential application as a nanoscale delivery system of other radioprotective phytochemicals.</p

Effect of calophyllolide on myeloperoxidase (MPO) activity.

<p>All mice were sacrificed on day 1 and day 5 post-operation, and skin tissue samples were collected to assess MPO activity (n = 3 mice per group per experiment). Data are represented as mean ± SEM and compared by one-way ANOVA. *** P<0.001.</p

Effect of calophyllolide on HaCaT and RAW264.7 cell viability.

<p>HPLC chromatograms of the isolated calophyollide <b>(A)</b> and standard control <b>(B)</b>. This compound was recorded at 233 nm, and its retention time is 36.6 min. <b>(C)</b> No effect of CP on the viability of both HaCaT and murine macrophage RAW264.7 cells after 24 h treatment.</p

Effect of calophyllolide (CP) on acceleration of wound closure.

<p>Effect of calophyllolide (CP) on acceleration of wound closure.</p

Anti-inflammatory and wound healing activities of calophyllolide isolated from <i>Calophyllum inophyllum</i> Linn

<div><p>Due to the high-cost and limitations of current wound healing treatments, the search for alternative approaches or drugs, particularly from medicinal plants, is of key importance. In this study, we report anti-inflammatory and wound healing activities of the major calophyllolide (CP) compound isolated from <i>Calophyllum inophyllum</i> Linn. The results showed that CP had no effect on HaCaT cell viability over a range of concentrations. CP reduced fibrosis formation and effectively promoted wound closure in mouse model without causing body weight loss. The underlying molecular mechanisms of wound repair by CP was investigated. CP markedly reduced MPO activity, and increased M2 macrophage skewing, as shown by up-regulation of M2-related gene expression, which is beneficial to the wound healing process. CP treatment prevented a prolonged inflammatory process by down-regulation of the pro-inflammatory cytokines—IL-1β, IL-6, TNF-α, but up-regulation of the anti-inflammatory cytokine, IL-10. This study is the first to indicate a plausible role for CP in accelerating the process of wound healing through anti-inflammatory activity mechanisms, namely, by regulation of inflammatory cytokines, reduction in MPO, and switching of macrophages to an M2 phenotype. These findings may enable the utilization of CP as a potent therapeutic for cutaneous wound healing.</p></div

Attenuation of inflammatory cytokines expression by calophyllolide.

<p>Serum levels of (<b>A</b>) IL-1β, (<b>B</b>) IL-6, (<b>C</b>) TNF-α, and (<b>D</b>) IL-10. Data are represented as mean ± SEM and compared by one-way ANOVA (n = 3 mice per group per experiment). * P<0.05, ** P<0.01, *** P<0.001.</p

Histological and quantitative analyses of the cutaneous wound healing of calophyllolide.

<p>Mice were daily treated with CP (6 mg/animal) and PI (100 mg/animal) until enthanasia. <b>(A)</b> Histological observation of collagen on wound healing at day 14 by Masson’s Trichrome staining. Reduction of collagenous scar (arrow head) in CP-treated group compared to vehicle- and PI-treated groups. Arrows indicate wound site with scale bar = 1cm. <b>(B)</b> Representative graph of semi-quantitative collagen content at day 10 and day 14 (n = 3–4 animals per group per experiment). Data are represented as mean ± SEM and compared by one-way ANOVA.</p