harmine and Skin-Neoplasms

Topics: Administration, Topical; Animals; Carcinoma, Squamous Cell; Cell Differentiation; Cells, Cultured; Epithelial-Mesenchymal Transition; Female; Gene Expression Regulation, Neoplastic; Gene Knockout Techniques; Harmine; Keratinocytes; Male; Mice; Skin Neoplasms; Twist-Related Protein 1; Ultraviolet Rays

Harman, a natural β-carboline alkaloid, has recently gained considerable interest due to its anticancer properties. However, its physicochemical characteristics and poor oral bioavailability have been limiting factors for its pharmaceutical development. In this paper, we described the complexation of harman (HAR) with β-cyclodextrin (βCD) as a promising alternative to improve its solubility and consequently its cytotoxic effect in chemoresistant melanoma cells (A2058 cell line). Inclusion complexes (βCD-HAR) were prepared using a simple method and then characterized by FTIR, NMR and SEM techniques. Through in silico studies, the mechanism of complexation of HAR with βCD was elucidated in detail. Both HAR and βCD-HAR promoted cytotoxicity, apoptosis, cell cycle arrest and inhibition of cell migration in melanoma cells. Interestingly, complexation of HAR with βCD enhanced its pro-apoptotic effect by increasing of caspase-3 activity (p < 0.05), probably due to an improvement in HAR solubility. In addition, HAR and βCD-HAR sensitized A2058 cells to vemurafenib, dacarbazine and 5FU treatments, potentializing their cytotoxic activity. These findings suggest that complexation of HAR with natural polymers such as βCD can be useful to improve its bioavailability and antimelanoma activity.

Topics: Antineoplastic Agents; Apoptosis; beta-Cyclodextrins; Cell Line, Tumor; Cell Movement; Cell Survival; Drug Resistance, Neoplasm; Harmine; Humans; Melanoma; Molecular Dynamics Simulation; Mutation; Proto-Oncogene Proteins B-raf; Skin Neoplasms

Dibenzofluoranthene-12,13-dihydrodiol (DBF-12,13-DHD) is six times more mutagenic in Salmonella TA100 than dibenzofluoranthene-3,4-dihydrodiol (DBF-3,4-DHD). However, these two major dibenzo[a,e]fluoranthene (DBF) proximate metabolites, which are immediate precursors of the corresponding diolepoxides, showed on an equimolar basis nearly identical initiation activities on mouse skin; they induced three times more papillomas than the parent hydrocarbon. On the other hand the epithelioma initiation capacities, i.e. the number of papillomas progressing to malignant tumours, of DBF or the two dibenzofluoranthene dihydrodiols were equivalent. Norharman, a putative vicinal diolepoxidation inhibitor in DBF metabolism when administered topically together with the initiation dose (100 nmol), strongly inhibited the induction of tumours by DBF-3,4-DHD and DBF. The relationship between in vitro mutagenic activity in Salmonella and the carcinogenicity of DBF metabolites in mice appears to be qualitative rather than quantitative.

Topics: Alkaloids; Animals; Carbolines; Carcinogens; Carcinoma; Female; Fluorenes; Harmine; Mice; Mice, Inbred Strains; Mutagenicity Tests; Mutagens; Mutation; Papilloma; Salmonella typhimurium; Skin Neoplasms; Structure-Activity Relationship