An insight into the cytotoxic activity of phytol at <i>in vitro</i> conditions

<div><p>The cytotoxicity of the diterpene alcohol, phytol, was evaluated by using the MTT assay <i>in vitro</i> against seven tumour cells and one normal cell of human origin. The compound tested induced concentration-dependent cytotoxic response in all cell lines, demonstrating to be most and least effective against the breast adenocarcinoma MCF-7 and the prostate adenocarcinoma PC-3 cells, respectively (IC₅₀ 8.79 ± 0.41 μM and 77.85 ± 1.93 μM). The IC₅₀ values towards the other five tumours (HeLa, HT-29, A-549, Hs294T and MDA-MB-231) ranged from 15.51 to 69.67 μM. However, mild toxicity was detected against the foetal lung fibroblast MRC-5 cells at the concentrations used (IC₅₀ 124.84 ± 1.59 μM). According to the experimental data obtained, this cost-effective natural product widely present in the biosphere may inspire the development of new drug-like substances with improved cytotoxic activity on breast cancer.</p></div

The redox couple avarol/avarone in the fight with malignant gliomas: the case study of U-251 MG cells

<p>This study aimed to screen <i>in vitro</i> antitumour activity of the redox couple avarol/avarone against the human malignant glioma cell line U-251 MG for the first time. Compared both with avarol and positive controls used (temozolomide and doxorubicin), avarone was found to be the most active compound with IC₅₀ value below 1 μM (IC₅₀ 0.68 ± 0.04 μM, 96 h). Considerable less DNA damage in the cells treated with avarol and avarone vs. doxorubicin (105 & 123% vs. 299%, respectively; untreated U-251 MG cells were used as a control, 100%), coupled with no sign of cytotoxicity against the normal human foetal lung fibroblast MRC-5 cells (IC₅₀ > 100 μM), has actually pointed out the importance of this marine sesquiterpenoid quinone structure as a promising lead compound in development of novel brain chemotherapeutics.</p

A contribution to pharmaceutical biology of freshwater sponges

<p><i>In vitro</i> anti-tumour and anti-radical activities of the acetone extract of the freshwater sponge <i>Ochridaspongia rotunda</i> were the subject of this study. The extract was found to be highly cytotoxic to human lung tumour cell line A-549 reaching IC₅₀ value of 5.01 ± 0.21 μg/mL. Indeed, it displayed only 2-fold less anti-tumour activity than doxorubicin (IC₅₀ value 2.42 ± 0.13 μg/mL) used as a positive control. The same extract was also found to be almost 37-fold more selective against A-549 vs. MRC-5 (normal) lung cells, in difference to weak selectivity of doxorubicin (less than 3-fold). Its profound anti-DPPH radical activity comparable to that of quercetin (IC₅₀ values 3.68 ± 0.19 and 3.14 ± 0.09 μg/mL, respectively) coupled with no signs of genotoxicity in the comet assay (MRC-5 cell line, vs. doxorubicin) has actually implicated the importance of this animal bioresource in searching for pharmaceutically useful bioactive compounds of natural origin.</p

<i>In vitro</i> evaluation of cytotoxic and mutagenic activity of avarol

<p>The cytotoxicity of avarol, a main secondary metabolite of the Mediterranean sponge <i>Dysidea avara</i>, was <i>in vitro</i> screened by MTT assay against four human tumour cell lines. The colon HT-29 tumour cells practically showed to be the only sensitive ones towards this organic compound. No toxicity was found against the fetal lung fibroblast MRC-5 cells at the concentrations tested. In comparison with doxorubicin, used as a positive control, avarol actually exhibited at least 588-fold less toxicity towards normal MRC-5 cells. Finally, comet assay indicated that DNA fragmentation was almost fivefold higher upon the treatment with doxorubicin, compared to avarol. The obtained results have actually confirmed that avarol scaffold may contribute to development of new cytostatics inspired by nature.</p