Time-kill kinetics and antimicrobial activities of Thai medical plant extracts against fish pathogenic bacteria

Unlocking the therapeutic mechanism of Caesalpinia sappan: a comprehensive review of its antioxidant and anti-cancer properties, ethnopharmacology, and phytochemistry

Herbal medicine are an invaluable reservoir of bioactive compounds, offering immense potential for novel drug development to address a wide range of diseases. Among these, Caesalpinia sappan has gained recognition for its historical medicinal applications and substantial therapeutic potential. This review explores the ethnopharmacological significance, phytochemical composition, and pharmacological properties of C. sappan, with a particular focus on its anticancer activities. Traditionally, C. sappan has been utilized for treating respiratory, gastrointestinal, and inflammatory conditions, demonstrating its broad therapeutic scope. The plant's rich array of bioactive compounds-flavonoids, triterpenoids, phenolic acids, and glycosides-forms the basis of its potent antioxidant, anti-inflammatory, and pharmacological effects. Modern pharmacological research has further substantiated its versatility, revealing anticancer, anti-diabetic, anti-infective, and hepatoprotective properties. However, significant challenges remain, including the need to unravel the precise molecular mechanisms underlying its anticancer effects, refine extraction and isolation methods for bioactive compounds, and validate its safety and efficacy through well-designed clinical trials. Particularly noteworthy is C. sappan's potential in combination therapies, where it may synergistically target multiple cancer pathways, enhance therapeutic outcomes, and mitigate adverse effects. This review synthesizes the findings from the past decade, providing a comprehensive evaluation of C. sappan's pharmacological promise while identifying critical areas for future research. By addressing these gaps, C. sappan could serve as a cornerstone for innovative therapeutic strategies, offering hope for improved management of cancer and other complex diseases.

Inhibition of Oral Pathogenic Bacteria, Suppression of Bacterial Adhesion and Invasion on Human Squamous Carcinoma Cell Line (HSC-4 Cells), and Antioxidant Activity of Plant Extracts from Acanthaceae Family

Medicinal plants have traditionally been used to treat various human diseases worldwide. In this study, we evaluated the leaf extracts of plants from the Acanthaceae family, specifically Clinacanthus nutans (Burm.f.) Lindau, Thunbergia laurifolia Lindl., and Acanthus ebracteatus Vahl., for their compounds and antioxidant activity. The ethanolic extracts of A. ebracteatus showed the highest total phenolic content at 22.55 mg GAE/g extract and the strongest antioxidant activities, with IC50 values of 0.24 mg/mL and 3.05 mg/mL, as determined by DPPH and ABTS assays. The antibacterial efficacy of these extracts was also tested against Streptococcus pyogenes, Streptococcus mutans, Staphylococcus aureus, and Klebsiella pneumoniae. The diameters of the inhibition zones ranged from 14.7 to 17.3 mm using the agar well diffusion method, with MIC and MBC values ranging from 7.81 to 250 mg/mL. Anti-biofilm formation, antibacterial adhesion, and antibacterial invasion assays further demonstrated that these medicinal plant extracts can inhibit bacterial biofilm formation and prevent the adhesion and invasion of oral pathogenic bacteria on the human tongue squamous cell carcinoma-derived cell line (HSC-4 cells). The ethanolic extracts of C. nutans and A. ebracteatus were able to inhibit the gtfD and gbp genes, which facilitate biofilm formation and bacterial adherence to surfaces. These findings provide new insights into the antibacterial and antioxidant properties of plant extracts from the Acanthaceae family. These activities could enhance the clinical and pharmaceutical applications of plant extracts as an alternative therapy for bacterial infections and a dietary supplement.

Bioactive compound from marine seagrass Streptomyces argenteolus TMA13: combatting fish pathogens with time-kill kinetics and live-dead cell imaging

Actinobacteria, pervasive in aquatic and terrestrial environments, exhibit a filamentous morphology, possess DNA with a specific G + C content and production of numerous secondary metabolites. This study, focused on actinobacteria isolated from marine seagrass, investigating their antibacterial activity against fish pathogens. Among 28 isolates, Streptomyces argenteolus TMA13 displayed the maximum zone of inhibition against fish pathogens-Aeromonas hydrophila (10 mm), Aeromonas caviae (22 mm), Edwardsiella tarda (17 mm), Vibrio harveyi (22 mm) and Vibrio anguillarum (12 mm) using the agar plug method. Optimization of this potent strain involved with various factors, including pH, temperature, carbon source and salt condition to enhance both yield production and antibacterial efficacy. In anti-biofilm assay shows the maximum percentage of inhibition while increasing concentration of TMA13 extract. Minimal Inhibitory Concentration (MIC) and Minimal Bactericidal Concentration (MBC) assays with TMA13 crude extract demonstrated potent activity against fish pathogens at remarkably low concentrations. Time-kill kinetics assay showcased growth curve variations over different time intervals for all fish pathogens treated with a 100 µg/ml concentration of crude extract, indicating a decline in cells viability and progression into the death phase. Additionally, fluorescence microscopic visualization of bacterial cells exposed to the extracts emitting green and red fluorescence, enabling live-dead cell differentiation was also studied. Further characterization of the crude extract through GC-MS and FT-IR analyses performed and identified secondary metabolites with functional groups exhibiting significant antibacterial activity. This study elucidates the capacity of Streptomyces argenteolus TMA13 to enhance the production of antibiotic compounds effective against fish pathogens.

The dual activity of CaONPs as a cancer treatment substance and at the same time resistance to harmful microbes

Nanotechnology holds significant promise for the development of novel and necessary products that enhance human health. Pharmacology and nanotechnology have contributed to developing advanced and highly effective drugs for cancer treatment and combating microbial infections. The microbiological effectiveness against the variety of examined microorganisms was assessed using the time killer curve, scanning electron microscopy (SEM), MIC techniques, and the agar well diffusion method. SEM was utilized to enhance the analysis of the mechanisms underlying the bio-interface interaction and intracellular localization of calcium oxide nanoparticles (CaONPs). The MTT test was used to examine the cytotoxicity of CaONP anticancer activity in various cancer cells, including colon, breast, and hepatic cells. The efficacy of CaONPs as an anticancer medication was elucidated by analyzing the gene expression of both treated and untreated cancer cells. MIC and MBC of CaONPs against Escherichia coli and Staphylococcus epidermidis were 150, 150, 150, and 200 µg/ml, respectively. The MIC and MFC of CaONPs against Candida albicans were 200 µg/ml and 250 µg/ml, respectively. The IC50 values of various CaONPs vary depending on the type of cancer cells. The gene expression analysis of breast cancer cells undergoing treatment revealed the identification of several cancer-controlling genes, namely BAX, BCL2, P53, TERT, KRAS1, KRAS2, and RB1. The study demonstrated the notable antibacterial efficacy of CaONPs, highlighting their potential as cancer therapies.

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

Background

The perennial plant Hypericum perforatum is widely distributed around the world. It has been used for many years in conventional medicine to treat a variety of illnesses, including stress, mild to moderate depression, and minor injuries. This study examined the antimicrobial activity of the H. perforatum total extract and its fractions (n-hexane, ethyl acetate, chloroform, and aqueous) against multi-drug-resistant (MDR) isolates that were gathered from clinical samples, including methicillin-resistant Staphylococcus aureus (MRSA), Enterococcus faecalis, Escherichia coli, and Klebsiella pneumonia.

Materials and Methods

Aerial parts of H. perforatum were collected and extracted using various solvents and were tested versus different isolated bacterial species. The inhibition zone of tested extracts was detected using an agar diffusion assay, and MICs were measured. Phytochemical analysis of promising H. perforatum extract was done using LC-ESI-MS/MS. Ultrastructure examination for the most altered bacteria used transmission electron microscopy. Antioxidant assays were done using DPPH and ABTS scavenging capacity methods. Cytotoxicity was reported versus Vero cells.

Results

Different extracts of H. perforatum showed promising antibacterial activity against the pathogens. While the subfractions of the total extract were observed to show lesser inhibition zones and higher MIC values than the total extract of H. perforatum against MDR strains, the total extract of H. perforatum demonstrated the most potent antimicrobial action with an inhibition zone range of 17.9-27.9 mm. MDR-K. pneumoniae was discovered to be the most susceptible strain, which is consistent with the antibacterial inhibitory action of H. perforatum whole extract. Additionally, after treatment at the minimum inhibitory concentration (MIC 3.9 μg/ml), the transmission electron microscope showed alterations in the ultrastructure of the K. pneumoniae cells. Methanol extract from H. perforatum has a CC50 value of 976.75 μg/ml.

Conclusion

Future inhibitors that target MDR strains may be revealed by these findings. Additionally, the extracts that were put to the test demonstrated strong antioxidant effects as shown by DPPH or ABTS radical-scavenging assays.