Bee venom is a very complex mixture produced and secreted by the honeybee (Apis mellifera). Melittin is a major component of bee venom that accounts for about 52% of its dry mass. A vast number of studies have been dedicated to the effects of melittin’s regulation of apoptosis and to the factors that induce apoptosis in various types of cancer such as breast, ovarian, prostate, lung. The latest evidence indicates its potential as a therapeutic agent in the treatment of leukaemia. The aim of our present study is to evaluate melittin’s ability to induce apoptosis in leukaemia cell lines of different origin acute lymphoblastic leukaemia (CCRF-CEM) and chronic myelogenous leukaemia (K-562). We demonstrated that melittin strongly reduced cell viability in both leukaemia cell lines but not in physiological peripheral blood mononuclear cells (PMBCs). Subsequent estimated parameters (mitochondrial membrane potential, Annexin V binding and Caspases 3/7 activity) clearly demonstrated that melittin induced apoptosis in leukaemia cells. This is a very important step for research into the development of new potential anti-leukaemia as well as anticancer therapies. Further analyses on the molecular level have been also planned (analysis of proapoptotic genes expression and DNA damages) for our next research project, which will also focus on melittin.

Tryptophan catabolites pathway disorders are observed in patients with depression. Moreover, single nucleotide polymorphisms of tryptophan hydroxylase genes may modulate the risk of depression occurrence. The objective of our study was to confirm the association between the presence of polymorphic variants of TPH1 and TPH2 genes, and the development of depressive disorders. Six polymorphisms were selected: c.804‐7C>A (rs10488682), c.‐1668T>A (rs623580), c.803+221C>A (rs1800532), c.‐173A>T (rs1799913)—TPH1, c.‐1449C>A (rs7963803), and c.‐844G>T (rs4570625)—TPH2. A total of 510 DNA samples (230 controls and 280 patients) were genotyped using TaqMan probes. Among the studied polymoorphisms, the G/G genotype and G allele of c.804‐7C>A—TPH1, the T/T homozygote of c.803+221C>A—TPH1, the A/A genotype and A allele of c.1668T>A—TPH1, the G/G homozygote and G allele of c.‐844G>T—TPH2, and the C/A heterozygote and A allele of c.‐1449C>A—TPH2 were associated with the occurrence of depression. However, the T/T homozygote of c.‐1668T>A—TPH1, the G/T heterozygote and T allele of c.‐844G>T—TPH2, and the C/C homozygote and C allele of c.‐1449C>A—TPH2 decreased the risk of development of depressive disorders. Each of the studied polymorphisms modulated the risk of depression for selected genotypes and alleles. These results support the hypothesis regarding the involvement of the pathway in the pathogenesis of depression.

The dominating hypothesis among numerous hypotheses explaining the pathogenesis of depressive disorders (DD) is the one involving oxidative and nitrosative stress. In this study, we examined the association between single-nucleotide polymorphisms of the genes encoding SOD2 (superoxide dismutase 2), CAT (catalase), GPx4 (glutathione peroxidase 4), NOS1 (nitric oxide synthase 1), NOS2 (nitric oxide synthase 2), and the development of depressive disorders. Our study was carried out on the DNA isolated from peripheral blood collected from 281 depressed patients and 229 controls. Using TaqMan probes, we genotyped the following six polymorphisms: c.47T > C (p.Val16Ala) (rs4880) in SOD2, c.-89A > T (rs7943316) in CAT, c.660T > C (rs713041) in GPx4, c.-420-34221G > A (rs1879417) in NOS1, c.1823C > T (p.Ser608Leu) (rs2297518), and c.-227G > C (rs10459953) in NOS2. We found that the T/T genotype of the c.47T > C polymorphism was linked with an increased risk of depression. Moreover, the T/T genotype and T allele of c.660T > C increased the risk of DD occurrence, while the heterozygote and C allele decreased this risk. On the other hand, we discovered that the A/A genotype of c.-89A > T SNP was associated with a reduced risk of DD, while the A/T genotype increased this risk. We did not find any correlation between the genotypes/alleles of c.-420-34221G > A, c.1823C > T, and c.-227G > C, and the occurrence of DD. In addition, gene-gene and haplotype analyses revealed that combined genotypes and haplotypes were connected with the disease. Moreover, we found that sex influenced the impact of some SNPs on the risk of depression. Concluding, the studied polymorphisms of SOD2, CAT and GPx4 may modulate the risk of depression. These results support the hypothesis that oxidative and nitrosative stresses are involved in the pathogenesis of depressive disorders.

HEMA (2-hydroxyethyl methacrylate), a methacrylate commonly used in dentistry, was reported to induce genotoxic effects, but their mechanism is not fully understood. HEMA may be degraded by the oral cavity esterases or through mechanical stress following the chewing process. Methacrylic acid (MAA) is the primary product of HEMA degradation. In the present work we compared cytotoxic and genotoxic effects induced by HEMA and MAA in human gingival fibroblasts (HGFs). A 6-h exposure to HEMA or MAA induced a weak decrease in the viability of HGFs. Neither HEMA nor MAA induced strand breaks in the isolated plasmid DNA, but both compounds evoked DNA damage in HGFs, as evaluated by the alkaline comet assay. Oxidative modifications to the DNA bases were monitored by the DNA repair enzymes Endo III and Fpg. DNA damage induced by HEMA and MAA was not persistent and was removed during a 120 min repair incubation. Results from the neutral comet assay indicated that both compounds induced DNA double strand breaks (DSBs) and they were confirmed by the γ-H2AX assay. Both compounds induced apoptosis and perturbed the cell cycle. Therefore, methacrylic acid, a product of HEMA degradation, may be involved in its cytotoxic and genotoxic action.