Active natural compounds perturb the melanoma risk-gene network.

Cutaneous melanoma is an aggressive type of skin cancer with a complex genetic landscape caused by the malignant transformation of melanocytes. This study aimed at providing an in silico network model based on the systematic profiling of the melanoma-associated genes considering germline mutations, somatic mutations, and genome-wide association study signals accounting for a total of 232 unique melanoma risk genes. A protein-protein interaction network was constructed using the melanoma risk genes as seeds and evaluated to describe the functional landscape in which the melanoma genes operate within the cellular milieu. Not only were the majority of the melanoma risk genes able to interact with each other at the protein level within the core of the network, but this showed significant enrichment for genes whose expression is altered in human melanoma specimens. Functional annotation showed the melanoma risk network to be significantly associated with processes related to DNA metabolism and telomeres, DNA damage and repair, cellular ageing, and response to radiation. We further explored whether the melanoma risk network could be used as an in silico tool to predict the efficacy of anti-melanoma phytochemicals, that are considered active molecules with potentially less systemic toxicity than classical cytotoxic drugs. A significant portion of the melanoma risk network showed differential expression when SK-MEL-28 human melanoma cells were exposed to the phytochemicals harmine and berberine chloride. This reinforced our hypothesis that the network modeling approach not only provides an alternative way to identify molecular pathways relevant to disease but it may also represent an alternative screening approach to prioritize potentially active compounds.

In Vitro Cytotoxic Effects of Ferruginol Analogues in Sk-MEL28 Human Melanoma Cells.

Ferruginol is a promising abietane-type antitumor diterpene able to induce apoptosis in SK-Mel-28 human malignant melanoma. We aim to increase this activity by testing the effect of a small library of ferruginol analogues. After a screening of their antiproliferative activity (SRB staining, 48 h) on SK-Mel-28 cells the analogue 18-aminoferruginol (GI50 ≈ 10 µM) was further selected for mechanistic studies including induction of apoptosis (DAPI staining, p < 0.001), changes in cell morphology associated with the treatment (cell shrinkage and membrane blebbing), induction of caspase-3/7 activity (2.5 at 48 h, 6.5 at 72 h; p < 0.0001), changes in the mitochondrial membrane potential (not significant) and in vitro effects on cell migration and cell invasion (Transwell assays, not significant). The results were compared to those of the parent molecule (ferruginol, GI50 ≈ 50 µM, depolarisation of mitochondrial membrane p < 0.01 at 72 h; no caspases 3/7 activation) and paclitaxel (GI50 ≈ 10 nM; caspases 3/7 activation p < 0.0001) as a reference drug. Computational studies of the antiproliferative activity of 18-aminoferruginol show a consistent improvement in the activity over ferruginol across a vast majority of cancer cells in the NCI60 panel. In conclusion, we demonstrate here that the derivatisation of ferruginol into 18-aminoferruginol increases its antiproliferative activity five times in SK-MEL-28 cells and changes the apoptotic mechanism of its parent molecule, ferruginol.

Potential Pharmacokinetic Interactions of Common Cardiovascular Drugs and Selected European and Latin American Herbal Medicines: A Scoping Review.

BACKGROUND: Herb-drug interactions are nowadays an important decision factor in many healthcare interventions. Patients with cardiovascular risk factors such as hyperlipidemia and hypertension are usually prescribed long-term treatments. We need more informed decision tools to direct future clinical research and decision making to avoid HDI occurrences in this group. METHODS: A scoping review was conducted using data from online databases such as PUBMED, the National Library of Medicine, and the electronic Medicines Compendium. Included studies consisted of the reported effects on Phase 1/2 and P-glycoprotein of herbal medicines listed in the medicines agencies of Latin America and Europe and drugs used for cardiovascular conditions (statins, diuretics, beta blockers, calcium channel blockers, and ACE inhibitors). The cross tabulation of the results allowed for finding potential HDI. RESULTS AND CONCLUSIONS: as per the preclinical data reviewed here, we encourage more clinical research on whether drugs with apparently very low interaction risk, such as pravastatin, nadolol, and nimodipine/nitrendipine, may help prevent HDI when statins, beta blockers, and calcium channel blockers, respectively, are prescribed for long-term treatments.