Quorum Sensing and NF-κB Inhibition of Synthetic Coumaperine Derivatives from Piper nigrum

Pseudomonas aeruginosa quorum sensing and biofilm attenuation by a di-hydroxy derivative of piperlongumine (PL-18)

Bacterial communication, Quorum Sensing (QS), is a target against virulence and prevention of antibiotic-resistant infections. 16 derivatives of Piperlongumine (PL), an amide alkaloid from Piper longum L., were screened for QS inhibition. PL-18 had the best QSI activity. PL-18 inhibited the lasR-lasI, rhlR-rhlI, and pqs QS systems of Pseudomonas aeruginosa. PL-18 inhibited pyocyanin and rhamnolipids that are QS-controlled virulence elements. Iron is an essential element for pathogenicity, biofilm formation and resilience in harsh environments, its uptake was inhibited by PL-18. Pl-18 significantly reduced the biofilm biovolume including in established biofilms. PL-18-coated silicon tubes significantly inhibited biofilm formation. The transcriptome study of treated P. aeruginosa showed that PL-18 indeed reduced the expression of QS and iron homeostasis related genes, and up regulated sulfur metabolism related genes. Altogether, PL-18 inhibits QS, virulence, iron uptake, and biofilm formation. Thus, PL-18 should be further developed against bacterial infection, antibiotic resistance, and biofilm formation.

Antimicrobial Activity of Spices Popularly Used in Mexico against Urinary Tract Infections

Urinary tract infections (UTIs) are the most common infectious diseases worldwide. These infections are common in all people; however, they are more prevalent in women than in men. The main microorganism that causes 80-90% of UTIs is Escherichia coli. However, other bacteria such as Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, Proteus mirabilis, and Klebsiella pneumoniae cause UTIs, and antibiotics are required to treat them. However, UTI treatment can be complicated by antibiotic resistance and biofilm formation. Therefore, medicinal plants, such as spices generally added to foods, can be a therapeutic alternative due to the variety of phytochemicals such as polyphenols, saponins, alkaloids, and terpenes present in their extracts that exert antimicrobial activity. Essential oils extracted from spices have been used to demonstrate their antimicrobial efficacy against strains of pathogens isolated from UTI patients and their synergistic effect with antibiotics. This article summarizes relevant findings on the antimicrobial activity of cinnamon, clove, cumin, oregano, pepper, and rosemary, spices popularly used in Mexico against the uropathogens responsible for UTIs.

Evaluation of Antimicrobial Activity and Cytotoxicity Effects of Extracts of Piper nigrum L. and Piperine

P. nigrum L. extracts and the piperine alkaloid have important antimicrobial, anti-inflammatory, and antioxidant properties. Therefore, in this study, we evaluated the antimicrobial activity and cytotoxicity of P. nigrum L. extracts and piperine, a compound isolated from the extracts of P. nigrum L. Extracts obtained via maceration, soxhlet, and purification steps, in addition to isolated piperine, were used in this study. Spectroscopic methods, such as nuclear magnetic resonance, scanning electron microscopy, X-ray diffraction, thermogravimetry, and differential scanning calorimetry, were used to characterize piperine. In the microbiological analyses, the extract obtained via maceration-derived sample showed high efficiency in inhibiting Salmonella spp. (MIC < 100 μg/mL). The extract obtained via a soxhlet-derived sample showed promising inhibitory activity against almost all microorganisms, with negligible inhibition of Pseudomonas aeruginosa. Favorable inhibition coefficients were also observed against Staphylococcus aureus and Salmonella spp. (MIC < 100 μg/mL) for the extract obtained via purification of the steps-derived sample. Piperine showed an excellent inhibition coefficient against most microorganisms, with inactivity only observed against P. aeruginosa. Cytotoxicity evaluation assays in cancer cell lines revealed that piperine exhibited inhibitory potential on all tested tumor cell lines, causing a decrease in cell viability and achieving an IC50 of less than 30 μg/mL. The analyzed extracts from P. nigrum L. seeds showed cytotoxic activity against tumor and non-tumor cell lines.

Curcumin Extraction, Isolation, Quantification and Its Application in Functional Foods: A Review With a Focus on Immune Enhancement Activities and COVID-19

An entirely unknown species of coronavirus (COVID-19) outbreak occurred in December 2019. COVID-19 has already affected more than 180 million people causing ~3.91 million deaths globally till the end of June 2021. During this emergency, the food nutraceuticals can be a potential therapeutic candidate. Curcumin is the natural and safe bioactive compound of the turmeric (Curcuma longa L.) plant and is known to possess potent anti-microbial and immuno-modulatory properties. This review paper covers the various extraction and quantification techniques of curcumin and its usage to produce functional food. The potential of curcumin in boosting the immune system has also been explored. The review will help develop insight and new knowledge about curcumin's role as an immune-booster and therapeutic agent against COVID-19. The manuscript will also encourage and assist the scientists and researchers who have an association with drug development, pharmacology, functional foods, and nutraceuticals to develop curcumin-based formulations.