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The tropolone-bearing sesquiterpenes juniperone A (1) and norjuniperone A (2) were isolated from the folk medicinal plant Juniperus chinensis, and their structures were determined by a combination of spectroscopic and crystallographic methods. Photojuniperones A1 (3) and A2 (4), bearing bicyclo[3,2,0]heptadienones derived from tropolone, were photochemically produced and structurally identified by spectroscopic methods. Predicted by the machine learning-based assay, 1significantly inhibited the action of tyrosinase. The new compounds also inhibited lipid accumulation and enhanced the extracellular glycerol excretion.

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.

3,3′-Diindolylmethane (DIM), a digestive metabolite originating from cruciferous vegetables, has dietary potential for the treatment of various human intestinal diseases. Although intestinal permeability dysfunction is closely related to the initiation and progression of human intestinal inflammatory diseases (IBDs), the effect of DIM on intestinal permeability is unclear. We evaluated the effect of DIM on the intestinal permeability of human intestinal cell monolayers and the animal model Caenorhabditis elegans,which were treated with IL-1β and Pseudomonas aeruginosa, respectively, to mimic IBD conditions. DIM substantially restored the intestinal permeability of differentiated Caco-2 cells by enhancing the expression of tight junction proteins (including occludin and ZO-1). Compared to the IL-1β single treatment (551.0 ± 49.0 Ω·cm2), DIM (10 μM) significantly increased the transepithelial electrical resistance (TEER) of Caco-2 cell monolayers (919.0 ± 66.4 Ω·cm2, p< 0.001). DIM also ameliorated the impaired intestinal permeability and extended the lifespan of C. elegansfed P. aeruginosa. The mean lifespan of DIM-treated worms (10.8 ± 1.3 days) was higher than that of control-treated worms (9.7 ± 1.1 days, p< 0.01). Thus, DIM is a potential nutraceutical candidate for the treatment of leaky gut syndrome by improving intestinal permeability.

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.

Abstract: Multiple sequence alignments showed that the prolines at the 25th, 129th, 153rd, 242nd, 322nd, and 434th amino acids in 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) from Agrobacterium sp. strain CP4 are strongly conserved in various prokaryotic EPSPS proteins. Single point mutations of the conserved prolines to alanine (P25A, P153A, P242A, P322A, and P434A) were introduced in the CP4 EPSPS in order to investigate the importance of the conserved prolines for the enzyme properties. The point mutations caused decreases in substrate binding affinity and catalytic efficiency as well as the glyphosate resistance, in general. Especially, the 25th and 242nd prolines located in the polypeptide hinges connecting top and bottom domains of CP4 EPSPS as well as the 434th proline at the C-terminus of the enzyme turned out to be crucial for the enzyme activity.