Medicinal and aromatic plants (MAPs) are known and have been long in use for a variety of health and cosmetics applications. Potential pharmacological usages that take advantage of bioactive plant‐derived compounds’ antimicrobial, antifungal, anti‐inflammatory, and antioxidant properties are being developed and many new ones explored. Some phytochemicals could trigger ROS‐mediated cytotoxicity and apoptosis in cancer cells. A lot of effort has been put into investigating novel active constituents for cancer therapeutics. While other plant‐derived compounds might enhance antioxidant defenses by either radical scavenging or stimulation of intracellular antioxidant enzymes, the generation of reactive oxygen species (ROS) leading to oxidative stress is one of the strategies that may show effective in damaging cancer cells. The biochemical pathways involved in plant‐derived bioactive compounds’ properties are complex, and in vitro platforms have been useful for a comprehensive understanding of the mechanism of action of these potential anticancer drugs. The present review aims at compiling the findings of particularly interesting studies that use cancer cell line models for assessment of antioxidant and oxidative stress modulation properties of plant‐derived bioactive compounds.

Lung cancer has a very high mortality‐to‐incidence ratio, representing one of the main causes of cancer mortality worldwide. Therefore, new treatment strategies are urgently needed. Several diseases including lung cancer have been associated with the action of reactive oxygen species (ROS) from which hydrogen peroxide (H₂O₂) is one of the most studied. Despite the fact that H₂O₂ may have opposite effects on cell proliferation depending on the concentration and cell type, it triggers several antiproliferative responses. H₂O₂ produces both nuclear and mitochondrial DNA lesions, increases the expression of cell adhesion molecules, and increases p53 activity and other transcription factors orchestrating cancer cell death. In addition, H₂O₂ facilitates the endocytosis of oligonucleotides, affects membrane proteins, induces calcium release, and decreases cancer cell migration and invasion. Furthermore, the MAPK pathway and the expression of genes related to inflammation including interleukins, TNF‐α, and NF‐κB are also affected by H₂O₂. Herein, we will summarize the main effects of hydrogen peroxide on human lung cancer leading to suggesting it as a potential therapeutic tool to fight this disease. Because of the multimechanistic nature of this molecule, novel therapeutic approaches for lung cancer based on the use of H₂O₂ may help to decrease the mortality from this malignancy.

Objective: To assess the clinical validity of polymerase chain reaction (PCR) based molecular methods in the microbiological diagnosis of culture negative infective endocarditis in a group of surgically treated patients. Design: Retrospective case–control study. Setting: Reference cardiovascular surgical centre. Patients and samples: 15 culture negative patients with infective endocarditis classified according to Duke criteria, with 17 heart valve samples; 13 age and sex matched control patients without infective endocarditis, with 13 valve samples. Interventions: Medical records were reviewed and clinical, demographic, and microbiological data collected, including results of molecular detection of bacteria and fungi from valve samples. The clinical validity of molecular diagnosis was assessed, along with the sensitivity and speed of the systems. Results: In the study group, 14 patients were PCR positive (93%). Organisms detected were streptococci (3), staphylococci (2), enterobacter (1), Tropheryma whippelii (1), Borrelia burgdorferi (1), Candida albicans (1), and Aspergillus species (2). Three cases were positive on universal bacterial detection but the pathogen could not be identified because of contaminating background. One case was negative. All but two positive cases showed clinical correlations. These two cases had no symptoms of infective endocarditis but there was agreement with the surgical findings. All control cases were PCR negative. Results were available within eight hours, and if sequencing was necessary, within 48 hours. Conclusions: PCR based molecular detection of pathogens in valve samples from surgically treated culture negative infective endocarditis patients is fast, sensitive, and reliable. The technology, combined with thorough validation and clinical interpretation, may be a promising tool for routine testing of infective endocarditis.

In the present study, use of a Helicteres isora stem bark extract for the biosynthesis of AgNPs is described. It was observed that the aqueous silver (Ag⁺) ions, once associated in the stem bark extract, were reduced in solution, thereby leading to formation of the stable AgNPs. These AgNPs were characterized using several techniques. The nanoparticles show a maximum absorbance at 419–431 nm in the ultraviolet-visible spectra. The presence of the steroid sapogenin was identified using Fourier transform-infrared (FTIR) spectroscopy. The reduction of the Ag⁺ ions to elemental silver was investigated by using X-ray diffraction (XRD). Transmission electron microscopy (TEM) revealed the formation of monodisperse, with low polydispersity, nanoparticles of 25.55 nm, and the presence of elemental silver was confirmed through energy dispersive spectroscopy (EDX) analysis. The AgNPs showed antioxidant activities such as DPPH, hydrogen peroxide and nitric oxide radical scavenging and a reducing power compared to the standard compounds. The antibacterial effect was determined against test strains, showing significant inhibition. The antiproliferative activity of the AgNPs was demonstrated using oral carcinoma (KB) cells with MTT, and confirmed using AO/EtBr, comet assay, DCFH-DA and Rhodamine 123 staining. In the toxicity study, a significant mortality rate was observed against Artemia with an IC₅₀ concentration of 70 μg mL⁻¹ and 108 h exposure. The NPs showed as cytotoxic against Artemia at 108 h, so they are cytotoxic at high concentrations and after prolonged exposure.