Objective: To evaluate the repellent activity of Eucalyptus and Azadirachta indica (A. indica) seed oil against filarial mosquito Culex quinquefasciatus (Cx. quinquefasciatus) from Purulia district of the West Bengal state, India. Methods: The repellent activity of Eucalyptus and A. indica seed oils (using coconut oil base) against Cx. quinquefasciatus mosquito were evaluated in indoor conditions. Three concentrations, 0%, 50% and 100% (v/v) of both the agents were considered in the studies. The protection percentage was determined, and the protection time was recorded. Results: The test oils showed excellent repellent action against Cx. quinquefasciatus. The A. indica seed oil provided 90.26% and 88.83% protection, and the Eucalyptus oil 93.37% and 92.04%, at concentrations 50% and 100% (v/v), respectively, with the protection time up to 240 min. There was no bite within 120 min and 180 min, respectively, due to the action of Eucalyptus andA. indica seed oil, and thus 100% protection from the bite of Cx. quinquefasciatus mosquito was achieved. Conclusions: The present study clearly demonstrates the potential of Eucalyptus and A. indica seed oils as topical repellents against Cx. quinquefasciatus, the mosquito vector of filariasis.

Indeed, medicinal importance of honey has been documented in the world's oldest medical literatures, and since the ancient times, it has been known to possess antimicrobial property as well as wound-healing activity. The healing property of honey is due to the fact that it offers antibacterial activity, maintains a moist wound condition, and its high viscosity helps to provide a protective barrier to prevent infection. Its immunomodulatory property is relevant to wound repair too. The antimicrobial activity in most honeys is due to the enzymatic production of hydrogen peroxide. However, another kind of honey, called non-peroxide honey (viz., manuka honey), displays significant antibacterial effects even when the hydrogen peroxide activity is blocked. Its mechanism may be related to the low pH level of honey and its high sugar content (high osmolarity) that is enough to hinder the growth of microbes. The medical grade honeys have potentin vitrobactericidal activity against antibiotic-resistant bacteria causing several life-threatening infections to humans. But, there is a large variation in the antimicrobial activity of some natural honeys, which is due to spatial and temporal variation in sources of nectar. Thus, identification and characterization of the active principle(s) may provide valuable information on the quality and possible therapeutic potential of honeys (against several health disorders of humans), and hence we discussed the medicinal property of honeys with emphasis on their antibacterial activities.

Objective: To evaluate the antibacterial potential of bioactive compounds from Persicaria hydropiper (L.) (P. hydropiper) against bacterial virulence proteins through molecular docking (MD) and experimental validation. Methods: Six bioactive compounds from P. hydropiper were investigated: catechin (CAT1), hyperin (HYP1), ombuin (OMB1), pinosylvin (PSV1), quercetin 3-sulfate (QSF1), and scutellarein (SCR1). Their binding affinities and potential binding pockets were assessed through MD against four bacterial target proteins with Protein Data Bank identifiers (PDB IDs): topoisomerase IV from Escherichia coli (E. coli) (PDB ID: 3FV5), Staphylococcus aureus (S. aureus) gyrase ATPase binding domain (PDB ID: 3U2K), CviR from Chromobacterium violaceum (C. violaceum) (PDB ID: 3QP1), and glycosyl hydrolase from Pseudomonas aeruginosa (P. aeruginosa) (PDB ID: 5BX9). Molecular dynamics simulations (MDS) were performed on the most promising compound-protein complexes for 50 nanoseconds (ns). Drug-likeness was evaluated using Lipinski's Rule of Five (RO5), followed by absorption, distribution, metabolism, excretion, and toxicity (ADMET) analysis using SwissADME and pkCSM web servers. Antibacterial activity was evaluated through disc diffusion assays, testing both individual compounds and combinations with conventional antibiotics [cefotaxime (CTX1, 30 μg/disc), ceftazidime (CAZ1, 30 μg/disc), and piperacillin (PIP1, 100 μg/disc)]. Results: MD revealed strong binding affinity (ranging from – 9.3 to – 5.9 kcal/mol) for all compounds, with CAT1 showing exceptional binding to 3QP1 (– 9.3 kcal/mol) and 5BX9 (– 8.4 kcal/mol). MDS confirmed the stability of CAT1-protein complexes with binding free energies of – 84.71 kJ/mol (5BX9-CAT1) and – 95.59 kJ/mol (3QP1-CAT1). Five compounds (CAT1, SCR1, PSV1, OMB1, and QSF1) complied with Lipinski's RO5 and showed favorable ADMET profiles. All compounds were non-carcinogenic, with CAT1 classified in the lowest toxicity class (VI). In antibacterial assays, CAT1 demonstrated significant activity against both gram-positive bacteria [Streptococcus pneumoniae (S. pneumoniae), S. aureus, and Bacillus cereus (B. cereus)] [zone diameter of inhibition (ZDI): 10 – 22 mm] and gram-negative bacteria [Acinetobacter baumannii (A. baumannii), E. coli, and P. aeruginosa] (ZDI: 14 – 27 mm). Synergistic effects were observed when CAT1 was combined with antibiotics and the growth inhibitory indices (GII) was 0.69 – 1.00. Conclusion P. hydropiper bioactive compounds, particularly CAT1, show promising antibacterial potential through multiple mechanisms, including direct inhibition of bacterial virulence proteins and synergistic activity with conventional antibiotics. The favorable pharmacological properties and low toxicity profiles support their potential development as therapeutic agents against bacterial infections.

Coriandrum sativum L. (C. sativum) is one of the most useful essential oil bearing spices as well as medicinal plants, belonging to the family Umbelliferae/Apiaceae. The leaves and seeds of the plant are widely used in folk medicine in addition to its use as a seasoning in food preparation. The C. sativum essential oil and extracts possess promising antibacterial, antifungal and anti-oxidative activities as various chemical components in different parts of the plant, which thus play a great role in maintaining the shelf-life of foods by preventing their spoilage. This edible plant is non-toxic to humans, and the C. sativum essential oil is thus used in different ways, viz., in foods (like flavouring and preservatives) and in pharmaceutical products (therapeutic action) as well as in perfumes (fragancias and lotions). The current updates on the usefulness of the plant C. sativum are due to scientific research published in different web-based journals.

Indeed, medicinal importance of honey has been documented in the world's oldest medical literatures, and since the ancient times, it has been known to possess antimicrobial property as well as wound-healing activity. The healing property of honey is due to the fact that it offers antibacterial activity, maintains a moist wound condition, and its high viscosity helps to provide a protective barrier to prevent infection. Its immunomodulatory property is relevant to wound repair too. The antimicrobial activity in most honeys is due to the enzymatic production of hydrogen peroxide. However, another kind of honey, called non-peroxide honey (viz., manuka honey), displays significant antibacterial effects even when the hydrogen peroxide activity is blocked. Its mechanism may be related to the low pH level of honey and its high sugar content (high osmolarity) that is enough to hinder the growth of microbes. The medical grade honeys have potent in vitro bactericidal activity against antibiotic-resistant bacteria causing several life-threatening infections to humans. But, there is a large variation in the antimicrobial activity of some natural honeys, which is due to spatial and temporal variation in sources of nectar. Thus, identification and characterization of the active principle(s) may provide valuable information on the quality and possible therapeutic potential of honeys (against several health disorders of humans), and hence we discussed the medicinal property of honeys with emphasis on their antibacterial activities.
Animals ; Anti-Bacterial Agents ; chemistry ; pharmacology ; Bacteria ; drug effects ; Honey ; analysis ; classification ; Humans