In Vitro Antibacterial and Phytochemical Screening of Hypericum perforatum Extract as Potential Antimicrobial Agents against Multi-Drug-Resistant (MDR) Strains of Clinical Origin

The In Vitro Assessment of Antibacterial and Antioxidant Efficacy in Rosa damascena and Hypericum perforatum Extracts against Pathogenic Strains in the Interplay of Dental Caries, Oral Health, and Food Microbiota

The rising demand for novel antibiotic agents prompts an investigation into natural resources, notably plant-derived compounds. In this study, various extracts (aqueous, ethanolic, aqueous-ethanolic, and enzymatic) of Rosa damascena and Hypericum perforatum were systematically evaluated against bacterial strains isolated from dental lesions (n = 6) and food sources (raw milk and broiler carcass, n = 2). Minimal inhibitory concentration (MIC), minimal bactericidal concentration (MBC), antibiofilm activity, and time-kill kinetics were assessed across a range of extract concentrations, revealing a dose-responsive effect. Notably, some extracts exhibited superior antibacterial efficacy compared to standard clinical antibiotics, and the time-kill kinetics demonstrated a rapid elimination of bacterial loads within 24 h. The susceptibility pattern proved strain-specific, contingent upon the extract type, yet all tested pathogens exhibited sensitivity. The identified extracts, rich in phenolic and polyphenolic compounds, as well as other antioxidant properties, contributed to their remarkable antibiotic effects. This comprehensive investigation not only highlights the potential of Rosa damascena and Hypericum perforatum extracts as potent antibacterial agents against diverse bacterial strains including caries pathogens, but also underscores their rapid action and dose-dependent efficacy. The findings suggest a promising avenue for harnessing plant-derived compounds in the development of novel antimicrobial strategies against dental caries and other oral inflammations, bridging the gap between natural resources and antibiotic discovery.

Bioassay-Guided Assessment of Antioxidative, Anti-Inflammatory and Antimicrobial Activities of Extracts from Medicinal Plants via High-Performance Thin-Layer Chromatography

Natural products and their analogues have contributed significantly to treatment options, especially for anti-inflammatory and infectious diseases. Thus, the primary objective of this work was to compare the bioactivity profiles of selected medicinal plants that are historically used in folk medicine to treat inflammation and infections in the body. Chemical HPTLC fingerprinting was used to assess antioxidant, phenolic and flavonoid content, while bioassay-guided HPTLC was used to detect compounds with the highest antibacterial and anti-inflammatory activities. The results of this study showed that green tea leaf, walnut leaf, St. John's wort herb, wild thyme herb, European goldenrod herb, chamomile flower, and immortelle flower extracts were strong radical scavengers. Green tea and nettle extracts were the most active extracts against E. coli, while calendula flower extract showed significant potency against S. aureus. Furthermore, green tea, greater celandine, and fumitory extracts exhibited pronounced potential in suppressing COX-1 activity. The bioactive compounds from the green tea extract, as the most bioactive, were isolated by preparative thin-layer chromatography and characterized with their FTIR spectra. Although earlier studies have related green tea's anti-inflammatory properties to the presence of catechins, particularly epigallocatechin-3-gallate, the FTIR spectrum of the compound from the most intense bioactive zone showed the strongest anti-inflammatory activity can be attributed to amino acids and heterocyclic compounds. As expected, antibacterial activity in extracts was related to fatty acids and monoglycerides.