In vitro Antioxidant Activity and In vivo Anti-inflammatory Effect of Ricinus communis (L.) and Withania somnifera (L.) Hydroalcoholic Extracts in Rats

Abstract Ricinus communis L. and Withania somnifera L. have traditionally been used as analgesic and anti-inflammatory remedies. The current study was aimed to evaluate the in vitro antioxidant potential and anti-inflammatory activity of hydroalcoholic extract of R. communis leaves (RCE) and W. somnifera roots (WSE) in Wistar rats. Total phenolic and flavonoid contents were quantified and in vitro antioxidant activity of extracts was determined through DPPH* scavenging, superoxide anion scavenging and reducing power activities, while anti-inflammatory activity was observed by xylene-induced ear edema and paw edema induced by egg albumin and carrageenan. RCE and WSE demonstrated considerable antioxidant activity in DPPH* scavenging (IC50: 250.10 and 309.42 µg/mL), superoxide anion scavenging (IC50: 193.42 and 206.81 ug/mL), and reducing power (maximum absorbance: 1.47±0.01 O.D and 1.28±0.01 O.D at 500 ug/mL) activities, respectively, with high phenolic and flavonoid contents. Both extracts showed dose-dependent edema inhibition in inflammation models. A maximum ear edema inhibitions by RCE (51.49±2.54%) and WSE (49.28±1.90%) at 500 mg/kg were observed when compared to indomethacin (56.42±13.17%) in xylene-induced ear edema. RCE and WSE showed a maximum percentage of paw edema inhibitions of 46.62±8.98% and 43.00±12.44%, respectively as compared to chlorpheniramine (62.02±12.21%) after 4 h in the egg albumin model. In carrageenan-induced paw edema, RCE (72.88±13.79%) significantly inhibited paw edema in comparison to WSE (57.81±17.43%) against diclofenac (89.93±18.53%). Conclusively, both plants have shown plausible antioxidant and anti-inflammatory activities that might be due to high phenolic and flavonoid contents. Moreover, RCE demonstrated more promising effects than WSE.

Quorum Sensing Interfering Strategies and Their Implications in the Management of Biofilm-Associated Bacterial Infections

Abstract The bacterial species employ various types of molecular communication systems recognized as quorum sensing for the synchronization of differential gene expression to regulate virulence traits and biofilm formation. A variety of quorum sensing inhibitors; molecules that interfere with quorum sensing among bacteria have been examined which can block the action of autoinducers. Moreover, the studies have scrutinized various enzymes for their quorum quenching activity resulting in the degradation of signaling molecules or blocking of gene expression. So far, the studies have found that these approaches are not only capable to reduce the pathogenicity and biofilm formation but also resulted in increased bacterial susceptibility to antibiotics and bacteriophages. The effectiveness of these strategies has been validated in different animal models and it seems that these practices will be transformed in near future to develop the medical devices including catheters, implants, and dressings for the prevention of bacterial infections. Although many of these approaches are still in the research stage, the increasing library of quorum quenching molecules and enzymes will open innovative perspectives for the development of antibacterial approaches which will extend the therapeutic arsenal against the pathogenic bacterial species.

Antimicrobial susceptibility of acinetobacter clinical isolates and emerging antibiogram trends for nosocomial infection management

Abstract: Introduction: The drug resistant Acinetobacter strains are important causes of nosocomial infections that are difficult to control and treat. This study aimed to determine the antimicrobial susceptibility patterns of Acinetobacter strains isolated from different clinical specimens obtained from patients belonging to different age groups. METHODS: In total, 716 non-duplicate Acinetobacter isolates were collected from the infected patients admitted to tertiary-care hospitals at Lahore, Pakistan, over a period of 28 months. The Acinetobacter isolates were identified using API 20E, and antimicrobial susceptibility testing was performed and interpreted according to Clinical and Laboratory Standards Institute (CLSI) guidelines. RESULTS: The isolation rate of Acinetobacter was high from the respiratory specimens, followed by wound samples. Antibiotic susceptibility analyses of the isolates revealed that the resistance to cefotaxime and ceftazidime was the most common, in 710 (99.2%) specimens each, followed by the resistance to gentamicin in 670 (93.6%) isolates, and to imipenem in 651 (90.9%) isolates. However, almost all isolates were susceptible to tigecycline, colistin, and polymyxin B. CONCLUSIONS: The present study showed the alarming trends of resistance of Acinetobacter strains isolated from clinical specimens to the various classes of antimicrobials. The improvement of microbiological techniques for earlier and more accurate identification of bacteria is necessary for the selection of appropriate treatments.