Natural antimicrobial agents, particularly plant extracts from Urtica dioica, Mentha piperita, Plantago lanceolata and Cynara scolymus, have attracted considerable attention due to their broad biological activity driven by diverse bioactive compounds and synergistic effects. The efficacy of these extracts depends on plant species, chemical composition, extraction method, and solvent, emphasizing the need for systematic evaluation of ethanolic and aqueous extracts as potential alternatives to synthetic antimicrobials. The aim of this study was to determine and compare the antimicrobial activity of ethanolic and aqueous leaf extracts of Urtica dioica, Mentha piperita, Plantago lanceolata and Cynara scolymus. Reliability was ensured through triplicate testing and standardised methodology (well diffusion method, 100 mg/ml concentration), confirming that the results are representative and statistically valid. Findings indicate that ethanolic extracts demonstrated significantly stronger antimicrobial activity than aqueous extracts (p < 0.05), particularly against Gram-positive bacteria (Staphylococcus epidermidis, Bacillus cereus, Enterococcus faecalis) and the fungus Candida albicans, while Gram-negative bacteria (Salmonella enteritidis, Yersinia enterocolitica) were largely resistant except Pseudomonas aeruginosa. Mentha piperita and P. lanceolate ethanolic extracts exhibited the broadest and most potent antimicrobial spectrum, U. dioica and C. scolymus leaves showed weaker activity but remain valuable sources of bioactive compounds.
This study evaluated the physicochemical characteristics, heavy metal contamination, and water quality of the surface water from the Okpare Olomu River in Ughelli South, Delta State, Nigeria. Water samples from four stations were analysed for physicochemical parameters, heavy metals (Fe, Pb, Cd, Cr, Cu, Zn, Mn), and the total hydrocarbon content (THC). The pH ranged from 5.71 to 5.86, indicating slightly acidic water. Electrical conductivity (17.23–24.23 µS/cm), total dissolved solids (6.18–13.46 mg/L), and total suspended solids (71.20–75.20 mg/L) were low, while dissolved oxygen (5.12–6.24 mg/L) and biochemical oxygen demand (3.34–7.43 mg/L) reflected moderate water quality. Heavy metal concentrations followed the order: Fe (0.86–2.35 mg/L) > Pb (0.00–0.23 mg/L) > Cd (0.02–0.07 mg/L) > Cr (0.06–0.12 mg/L) > Cu (0.06–0.09 mg/L) > Zn (0.13–0.16 mg/L) > Mn (0.01–0.02 mg/L), with Fe, Pb, and Cd exceeding the permissible limits established by NESREA, USEPA, and the WHO. THC ranged 2.85–3.62 mg/L. The Water Quality Index (WQI: 136.21–1113.24) classified all stations as Grade E and unsuitable for drinking, while the Comprehensive Pollution Index (CPI: 0.66–2.20) indicated station 2 as severely polluted, stations 1 and 3 as moderately polluted, and station 4 as slightly polluted. Health risk assessment revealed non-carcinogenic risk due to arsenic exposure (HI > 1), and integrated carcinogenic risk suggested a high potential for cancer among consumers. These findings highlight the urgent need for mitigation strategies, continuous monitoring, and public health interventions to reduce heavy metal contamination and protect communities dependent on the Okpare Olomu River.
Upon the first discovery, this publication provides the results of the examination and documentation of the female genitalia of Dvidulopsis Stonis & Diškus, an endemic Neotropical genus previously known only from male specimens. It also describes Stigmella mariusi Stonis & Diškus, sp. nov., a previously overlooked Acalypha-feeding species of Nepticulidae from the western premontane Amazon.
This study evaluated four landraces of local dill (Anethum graveolens) from Ardabil, Moghan, Mashhad, and Kerman, with the objective of assessing genetic and phytochemical variabilities. Plants were cultivated under field conditions on loamy soil and harvested at full flowering, the stage associated with maximum production of essential oil. Essential oils were extracted from leaves and flowers using low-temperature oven drying (40°C) and assessed via gas chromatography-mass spectrometry for measuring major constituents, including carvone, limonene, α-phellandrene, myristicin, dill ether, and dillapiole. Genotype × trait biplot analysis explained 82% of the total variation, and positive associations were observed between myristicin and dill ether, as well as between α-terpinene and α-pinene, while negative correlations were found between these compounds and α-terpinolene, dibutyl phthalate, and other minor constituents. Trait discrimination and representativeness analyses identified β-pinene and sabinene as the most informative for differentiating genotypes, followed by 1-terpineol, 5-hydroxymethylfurfural, and 5-epi-neointermedeol. Although highly abundant, such traits as essential oil, carvone, and limonene exhibited low discriminative potential. Among genotypes, Moghan displayed the highest essential oil, D-carvone, and l-limonene content, consistent with a seed-type chemotype dominated by carvone and limonene. Ardabil was rich in myristicin, dill ether, and α-phellandrene, representing a herb-type chemotype. Mashhad emerged as the most favourable genotype overall, combining desirable essential oil yield with moderate stability, while Kerman exhibited a high and stable dillapiole content, making it suitable for applications requiring consistent essential oil quality.
Metal pollution of aquatic ecosystems has raised concerns about their uptake by aquatic organisms and subsequent biomagnification along the aquatic food chain. This study determined trace metal distribution in Tilapia zillii and Synodontis schall from the Siluko River in Edo State, Nigeria. Fresh fish samples were harvested monthly from September 2021 to August 2022 with the assistance of artisanal fishermen. Trace metal contents in the gills, liver, and muscles were determined using atomic absorption spectrophotometer. The metal pollution index (MPI) was used to estimate the extent of metal bioaccumulation in the fishes. Results showed species variation in metal accumulation in various organs: T. zillii had a higher mean content of Cu, Zn, Mn and Fe in all the organs, while S. schall had a higher mean content of Ni, Cr, and Pb in all the organs. The MPI values ranged from 5.28 to 5.94 in the organs of T. zillii and S. schall. The order of MPI values in T. zillii was muscles > liver > gills; in S. schall, it was liver > gills > muscles. The results indicate trace metal contamination of fishes due to aquatic pollution. High MPI values is an indication of the degree of metal pollution of the Siluko River and the high susceptibility of these metals to bioaccumulation in the fishes. This predisposes the fishes to metal toxicity and portends health risk to fish consumers. The continuous monitoring of activities within the river watershed to mitigate heavy metal pollution is recommended.
