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.

This study evaluates the efficiency of 20 Natural Deep Eutectic Solvents (NADES) formulations for extracting curcuminoids and other bioactive compounds from turmeric and emphasize their ability to preserve and enhance antioxidant, antimicrobial, antidiabetic, and skin depigmentation effects. The NADES formulations, prepared using choline chloride (ChCl) combined with sugars, carboxylic acids, glycerol, amino acids, urea, polyols, and betaine, were assessed for their extraction efficiency based on the total phenolic content and curcumin concentration. Fourier transform infrared spectroscopy was employed to characterize the synthesized NADES and confirm their chemical composition. Bioactivity evaluations included antioxidant assays (ABTS and DPPH), antidiabetic tests (α-amylase inhibition), antimicrobial assays, and skin depigmentation (tyrosinase inhibition). The results demonstrated that NADES significantly enhanced the extraction efficiency and bioactive properties of turmeric extracts compared to water as a conventional green solvent. NADES 18 (ChCl/1,2-propanediol/water 1:1:1) and NADES 19 (glycerol/betaine/water 1:1:3) exhibited the highest extraction yields, with curcumin concentrations of 30.73 ± 1.96 mg/g and 31.70 ± 2.02 mg/g, respectively, outperforming water (26.91 ± 1.72 mg/g), while NADES 17 (ChCl/1,2-propanediol/water 0.5:3:0.5:5) and NADES 20 (glycerol/lysine/water 1:1:3) exhibited the most potent antioxidant activity. Furthermore, NADES 14 (ChCl/lactic acid/water 1:2:5) demonstrated the strongest tyrosinase inhibition (98.7%), supporting its potential for skin-brightening applications, including notable α-amylase inhibition exceeding 90%. This study aligns with the principles of green chemistry, as NADES are effective and sustainable solvents for natural product extraction. The presenting benefits of improved extraction efficiency and enhanced bioactivities position NADES as a promising and eco-friendly approach for developing efficient bioactive compound extraction methodologies.

Frankincense resin (Boswellia serrata), native to arid regions of India, the Middle East, and parts of Africa, has been highly valued for its medicinal properties. This study evaluated the antimicrobial potential of methanolic extracts of Boswellia serrata resin against Staphylococcus aureus, Pseudomonas aeruginosa, and Listeria monocytogenes. High-performance thin-layer chromatography (HPTLC) coupled with bioautography identified bioactive zones, while Liquid Chromatography–Mass Spectrometry (LC-MS) quantified the phenolic and terpenoid compounds. The cytotoxicity was assessed on HaCaT human keratinocyte cells to evaluate the safety for dermatological applications. The results demonstrated significant antibacterial activity, particularly against S. aureus and L. monocytogenes. The bioautograms revealed that samples from central and southern Serbia showed the highest antimicrobial effect against the tested bacterial strains. The active compounds included 11-keto-β-boswellic acid (up to 3733.96 μg/g), gallic acid (110.93 μg/g), and naringenin (53.13 μg/g). Cytotoxicity assays confirmed non-toxic effects at 10 µg/mL, with sample 6 enhancing the keratinocyte viability by 137%, while higher concentrations (50 µg/mL) showed variable cytotoxicity. These findings highlight the potential of B. serrata resin as a natural antimicrobial agent, particularly against antibiotic-resistant pathogens. Its therapeutic applicability in pharmaceutical and cosmetic formulations is promising provided that dosing ensures a balance between efficacy and safety.

This study aimed to examine wild-growing Hypericum perforatum L. tea (Hyperici herba) collected from Rtanj Mountain (Serbia). This research includes the following approaches: phytochemical and antioxidant characterization of H. perforatum infusion tea to determine its realistic composition (What do we consume when drinking the tea?), as well as a detailed examination of methanol(ic) extracts as the optimal extraction system. Due to the broad spectrum of both polar and nonpolar metabolites, 80% methanolic and pure methanol extracts were prepared for ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC Q-ToF) characterization through untargeted metabolomics analysis. Given the high diversity of compounds identified, the 80% methanolic extract was selected for further antioxidant examination and bioautographic characterization, including an antimicrobial activity assessment. UHPLC Q-ToF analysis identified 35 phenolics in the methanolic extract, compared to 25 metabolites in the infusion tea. The main differences were observed in flavonol/flavan-3-ol aglycones, xantones, and coumestans, which are more nonpolar compounds found only in the methanol(ic) system. Notably, specific H. perforatum metabolites were entirely absent in the infusion tea. Specifically, pseudohypericin, pseudoprotohypricin, and adhyperfirin were detected in the pure methanol extract, whereas hyperfirin was present in both methanol(ic) extracts. Additionally, eight furano-polycyclic polyprenylated acilphloroglucinols (FPPAPs) were identified in the methanol(ic) extracts as possible products of the thermal degradation and/or oxidation of hypericin/hyperforin. Both the infusion tea and methanolic extracts exhibited excellent antioxidant properties, with variations depending on the applied assay. High-performance thin-layer chromatography (HPTLC) analysis also confirmed the presence of a wide spectrum of phytochemical classes. Bioautography confirmed a promising activity of methanolic extracts against both Staphylococcus aureus and Klebsiella pneumoniae.

Cotinus coggygria Scop. (Anacardiaceae), known as 'smoke tree' or 'smoke bush' is a medicinal plant with recognised anti-inflammatory, antioxidative, antibacterial, antiviral, anticancer, antigenotoxic, and hepatoprotective activity. This study investigated the effect of spontaneous lactic acid fermentation on the extraction yield of bioactive compounds with antioxidant, antibacterial, and anti-inflammatory activities from C. coggygria via high-performance thin-layer chromatography (HPTLC) coupled with (bio)assays in effect-directed analysis (EDA). Results showed that spontaneous fermentation increased the extraction of phenolics by 45%, but not flavonoids. There was no significant increase in α-amylase and COX-1 inhibition, but a significant increase in terpenoid content, antioxidant activity, and antimicrobial activity. These findings confirm that lipophilic antioxidants are more potent and also suggest that antimicrobial activity is associated with the increased extraction of triterpenoids. The FTIR spectra of eluted bioactive zones with high antimicrobial activity also indicate the presence of fatty acids, phytosterols, and triterpenoids.