Search

The high prevalence of methicillin-resistant Staphylococcus aureus(MRSA) infection threatens the effectiveness of current clinical settings. Antimicrobial photodynamic therapy (APDT) is a promising alternative to antibiotics for treating infections due to its low resistance. This study aimed to evaluate the antibacterial properties of APDT with L. fischeriextract (LFE) against MRSA and various skin and oral pathogens in vitro and its photopharmaceutical actions in Caenorhabditis elegans. The antimicrobial activities of APDT with LFE against pathogens were evaluated using plate counting method. The chemical profile was characterized using high-performance liquid chromatography and spectrophotometry. The growth rate assay, lifespan assay, and bacterial attachment on worms were performed to assess the therapeutics effects in C. elegans. The swab method was used for the detection of pathogens on the micropig skin surface. The APDT treatment with L. fischeriextract (LFE, 20 µg/mL) and red light (intensity of 120 W/m2) reduced 4.3–4.9 log (colony forming unit/mL) of Staphylococcus aureus, MRSA, Cutibacterium acnes, Streptococcus mutans; and 2.4 log (CFU/mL) of Candida albicans. Chemical analysis revealed that LFE enriched three active photosensitizers. APDT reduced bacterial populations on worms, recovered growth retardation, and improved lifespan in MRSA-infected C. eleganswithout causing severe side effects. The surface eradication of MRSA after exposure to LFE with red light was demonstrated on micropig skin. These findings highlight the significance of L. fischerias a natural resource for the safe phototreatment of MRSA infection in the biomedical and cosmeceutical industries.

In addition to synthetic and semisynthetic compounds, natural products have received much attention as prolific sources of lead compounds with therapeutic effects on various diseases. In the process of screening the bioactivities of potential candidates, an in vivo assay is very important for providing meaningful insight into the efficacy, adverse effects, and modes of action that are relevant to humans. Among the many experimental models, Caenorhabditis elegansis particularly efficient due to its advantages in morphology, behavior, and genetic aspects. This review summarizes some basic and useful techniques commonly used in screening the bioactivities of natural products. Recent studies of naturally occurring extracts as well as bioactive compounds in various areas, namely, anti-aging, anti-neurodegeneration, anti-obesity, anti-infection, and gut health, are reviewed as examples of the applicability of the C. elegansmodel. Technological developments that incorporate C. elegansin other fields, such as instrumental analysis and emerging methods, are also discussed in this paper.