Denis Mitov

Dengue fever remains a major global health concern due to the absence of approved antiviral therapies specifically targeting dengue virus infection. In this study, an integrated in silico drug repurposing strategy was employed to identify potential therapeutic candidates against dengue virus. The first approach combined electron–ion interaction potential (EIIP)-guided screening of FDA-approved compounds with molecular docking against the dengue virus prM–E envelope glycoprotein complex, followed by post-docking MM-GBSA rescoring of selected candidates to refine binding affinity predictions. The second approach applied network-based drug repurposing using the Drugst.One platform, incorporating disease-associated human gene networks to identify compounds with potential host-directed therapeutic relevance. The EIIP–docking workflow identified several promising candidates, particularly antiviral agents such as acyclovir, ganciclovir, and entecavir, as well as compounds including dantrolene and ephedrine. MM-GBSA analysis supported the stability of acyclovir and ganciclovir binding, while highlighting limitations of docking-only ranking for certain candidates. Network-based analysis independently identified clinically relevant compounds, including atorvastatin, rosuvastatin, ciclesonide, mycophenolic acid, and dantrolene, suggesting overlap between viral-targeted and host-centered repurposing strategies. ADMET profiling further prioritized compounds with favorable pharmacokinetic and toxicity characteristics. These findings demonstrate that integrating structure-based and network-based computational repurposing approaches can efficiently identify promising dengue therapeutic candidates for future experimental validation.

Lemon balm (Melissa officinalis L.) is a well-established medicinal plant prized for its rich content of bioactive compounds. This study explored how artificial cadmium (Cd) contamination of soil affects the accumulation of heavy metal(oid)s, antioxidant activity, and the concentration of rosmarinic acid in lemon balm. At a soil Cd level of 20 mg/kg, plant growth was reduced, while the concentrations of most other elements, antioxidant activity, total phenolics, and flavonoids decreased, and the rosmarinic acid content increased slightly. In contrast, lower Cd levels (5 and 10 mg/kg) led to a modest increase in antioxidant activity and phenolic content. Cadmium accumulation in the aerial parts exceeded the WHO limit for medicinal plants. Although minor improvements in antioxidant properties were observed at lower Cd levels, and rosmarinic acid increased at 20 mg/kg, the health risks associated with Cd accumulation remain a concern. Therefore, monitoring Cd content in lemon balm grown on contaminated soils is essential to ensure its safe medicinal use.

The optimized electrochemical method, cyclic voltammetry, was applied to investigate the antioxidant capacity of water extracts of Rosa canina L. fruits. Scan speeds (25, 50, and 75 mV/s) and pH (2, 4.5, and 7) were varied and optimal conditions were found at 75 mV/s and pH 4.5. Cyclic voltammograms, recorded from 0 to 1200 mV, showed anodic peaks for catechin-type flavonoids and quercetin. Spectrophotometric tests (FRAP, CUPRAC, DPPH, ABTS) and determination of total polyphenols content (TPC), total flavonoids content (TFC), and vitamin C content were also conducted. FRAP and CUPRAC values ranged from 0.534 to 0.710 mmol Fe/g dw and from 103 to 174 mg TE/g dw, respectively. ABTS values were in the interval from 566 to 623 mg TE/g dw, while DPPH values ranged from 113 to 188 mg TE/g dw. Total polyphenols content and total flavonoids content ranged from 24.0 to 38.9 mg GAE/g dw, and from 12.7 to 21.5 mg CE/g dw, respectively. The concentrations of vitamin C were in the interval from 2.78 to 3.67 mg/g dw. Pearson’s analysis showed good correlations between ABTS and DPPH (R² = 0.87), FRAP and DPPH (R² = 0.85), FRAP and ABTS (R² = 0.86), TPC and in vitro tests (0.5 < R² < 0.77), and TFC and in vitro tests (0.47 < R² < 1). For the purpose of classifying spectrophotometric tests for determining antioxidant activity, hierarchical cluster analysis was performed.

Lemon balm is a plant widely used across various industries worldwide, and it contains a significant number of phenolic compounds that can positively affect human health. Given its extensive use today, this study determined the total polyphenols and flavonoid contents, antioxidant activities, rosmarinic acid content, and heavy metal(oid)s levels in the leaves of the pot-grown lemon balm. The heavy metal(oid)s content was compared with the maximum permissible concentrations for medicinal plants, as the World Health Organization (WHO) recommended. The results showed that all analyzed elements (As, Cd, Co, Cu, Zn, Mn, Ni and Pb) concentrations were within the recommended limits. The phenolic compound content of lemon balm was compared with literature data for wild-grown lemon balm samples.