In silico screening and validation of KPHS_00890 protein of Klebsiella pneumoniae proteome: An application to bacterial resistance and pathogenesis

Extracts of Selected South African Medicinal Plants Mitigate Virulence Factors in Multidrug-Resistant Strains of Klebsiella pneumoniae

The emergence of multidrug-resistant (MDR) Klebsiella pneumoniae remains a global health threat due to its alarming rates of becoming resistant to antibiotics. Therefore, identifying plant-based treatment options to target this pathogen's virulence factors is a priority. This study examined the antivirulence activities of twelve plant extracts obtained from three South African medicinal plants (Lippia javanica, Carpobrotus dimidiatus, and Helichrysum populifolium) against carbapenem-resistant (CBR) and extended-spectrum beta-lactamase (ESBL) positive K. pneumoniae strains. The plant extracts (ethyl acetate, dichloromethane, methanol, and water) were validated for their inhibitory activities against bacterial growth and virulence factors such as biofilm formation, exopolysaccharide (EPS) production, curli expression, and hypermucoviscosity. The potent extract on K. pneumoniae biofilm was observed with a scanning electron microscope (SEM), while exopolysaccharide topography and surface parameters were observed using atomic force microscopy (AFM). Chemical profiling of the potent extract in vitro was analysed using liquid chromatography-mass spectrometry (LC-MS). Results revealed a noteworthy minimum inhibitory concentration (MIC) value for the C. dimidiatus dichloromethane extract at 0.78 mg/mL on CBR- K. pneumoniae. L. javanica (ethyl acetate) showed the highest cell attachment inhibition (67.25%) for CBR- K. pneumoniae. SEM correlated the in-vitro findings, evidenced by a significant alteration of the biofilm architecture. The highest EPS reduction of 34.18% was also noted for L. javanica (ethyl acetate) and correlated by noticeable changes observed using AFM. L. javanica (ethyl acetate) further reduced hypermucoviscosity to the least length mucoid string (1 mm-2 mm) at 1.00 mg/mL on both strains. C. dimidiatus (aqueous) showed biofilm inhibition of 45.91% for the ESBL-positive K. pneumoniae and inhibited curli expression at 0.50 mg/mL in both K. pneumoniae strains as observed for H. populifolium (aqueous) extract. Chemical profiling of L. javanica (ethyl acetate), C. dimidiatus (aqueous), and H. populifolium (aqueous) identified diterpene (10.29%), hydroxy-dimethoxyflavone (10.24%), and 4,5-dicaffeoylquinic acid (13.41%), respectively, as dominant compounds. Overall, the ethyl acetate extract of L. javanica revealed potent antivirulence properties against the studied MDR K. pneumoniae strains. Hence, it is a promising medicinal plant that can be investigated further to develop alternative therapy for managing K. pneumoniae-associated infections.

M. G, Dharmashekar C, G. D, M. R. SC, Srinivasa C, Shati AA, Alfaifi MY, Elbehairi SEI, Achar RR, Silina E, Stupin V, Manturova N, Shivamallu C, Kollur SP. Cell cycle arrest and apoptotic studies of Terminalia chebula against MCF-7 breast cancer cell line: an in vitro and in silico approach

Breast cancer is a leading cause of mortality in women, and alternative therapies with fewer side effects are actively being explored. Breast cancer is a significant global health concern, and conventional treatments like radiotherapy and chemotherapy often have side effects. Medicinal plant extracts offer a promising avenue for the development of effective and safe anticancer therapies. Terminalia chebula, a plant known for its medicinal properties, was selected for investigation in this study. We aimed to assess the antiproliferative effects of TCF extract on breast cancer cells and explore the potential role of saccharopine, a phytochemical found in TCF, as an anticancer agent. MCF7 breast cancer cell lines were exposed to TCF extract, and cell viability and apoptosis assays were performed to evaluate the antiproliferative and apoptogenic effects. Molecular docking studies were conducted to assess the binding affinity of saccharopine with EGFRs. Molecular dynamics simulations and binding energy calculations were employed to analyze the stability of the EGFR-saccharopine complex. The TCF extract exhibited significant antiproliferative effects on MCF7 breast cancer cells and induced apoptosis in a dose-dependent manner. Molecular docking analysis revealed that saccharopine demonstrated a higher binding affinity with EGFR compared to the reference compound (17b-estradiol). The subsequent MDS simulations indicated stable binding patterns and conformation of the EGFR-saccharopine complex, suggesting a potential role in inhibiting EGFR-mediated signaling pathways. The investigation of Terminalia chebula fruit extract and its phytochemical saccharopine has revealed promising antiproliferative effects and a strong binding affinity with EGFR. These findings provide a foundation for future research aimed at isolating saccharopine and conducting in vivo studies to evaluate its potential as a targeted therapy for breast cancer. The development of novel anticancer agents from plant sources holds great promise in advancing the field of oncology and improving treatment outcomes for breast cancer patients.