Investigating the anti-inflammatory effects of high molecular weight secretions from Limosilactobacillus reuteri PTCC 1655 on LPS-stimulated PMA-differentiated THP-1 cells.

AIMS: This study was done to investigate the anti-inflammatory effects of high molecular weight secretions from Limosilactobacillus reuteri PTCC 1655 probiotic bacteria on lipopolysaccharide (LPS)-stimulated phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 cells. METHODS AND RESULTS: After culturing the bacterium, the crude cell-free supernatant was fractionated on the basis of molecular weights using ultrafiltration. Also, a heat-killed and sonicated fraction was obtained from the biomass of the bacterial culture. All fractions were used to measure their anti-inflammatory effects on PMA-differentiated THP-1 cells following LPS stimulation by quantifying various cellular markers of inflammation. The results demonstrated that various L. reuteri PTCC 1655-derived fractions, especially the >100 kDa supernatant fraction decreased some of the inflammatory cytokines and mediators, including tumour necrosis factor-α, interleukin-1, nitric oxide, cyclooxygenase-2, matrix metalloproteinase-9 and interleukin-6, which are critical for the pathogenesis of some inflammatory diseases. CONCLUSION: It is concluded that the L. reuteri PTCC 1655-derived high molecular weight fractions significantly reduce inflammation and therefore could be appropriate candidates for future medical studies. SIGNIFICANCE AND IMPACT OF THE STUDY: Providing new insights about the significance of L. reuteri PTCC 1655-derived extracts and their potential to modulate inflammation.

Antimicrobial peptides of the vaginal innate immunity and their role in the fight against sexually transmitted diseases.

Some antimicrobial peptides (AMPs) are produced in the vaginal innate immune system and play an important role in protecting this organ against pathogenic agents. Moreover, sexually transmitted diseases have become a major problem in human societies and are rapidly spreading. The emergence of antibiotic-resistant microbes (superbugs) can pose a major threat to human societies and cause rapid spread of these diseases. Finding new antimicrobial compounds to fight superbugs is therefore essential. It has been shown that AMPs have good potential to become new antibiotics. The most important AMPs in the vaginal innate immune system are defensins, secretory leucocyte protease inhibitors, calprotectin, lysozyme, lactoferrin and elafin, which play an important role in host defence against sexually transmitted infections, modulation of immune responses and anticancer activities. Some AMPs, such as LL-37, magainin 2 and nisin, show both spermicidal and antimicrobial effects in the vagina. In this summary, we will discuss vaginal AMPs and continue to address some of the challenges of using peptides to control pathogens that are effective in sexually transmitted diseases.