Inhibitory effects of several saturated fatty acids and their related fatty alcohols on the growth of Candida albicans

Oleic Acid and Palmitic Acid from Bacteroides thetaiotaomicron and Lactobacillus johnsonii Exhibit Anti-Inflammatory and Antifungal Properties

A decrease in populations of Bacteroides thetaiotaomicron and Lactobacillus johnsonii is observed during the development of colitis and fungal overgrowth, while restoration of these populations reduces inflammatory parameters and fungal overgrowth in mice. This study investigated the effect of two fatty acids from B. thetaiotaomicron and L. johnsonii on macrophages and Caco-2 cells, as well as their impact on the inflammatory immune response and on Candida glabrata overgrowth in a murine model of dextran sulfate sodium (DSS)-induced colitis. Oleic acid (OA) and palmitic acid (PA) from L. johnsonii and B. thetaiotaomicron were detected during their interaction with epithelial cells from colon samples. OA alone or OA combined with PA (FAs) reduced the expression of proinflammatory mediators in intestinal epithelial Caco-2 cells challenged with DSS. OA alone or FAs increased FFAR1, FFAR2, AMPK, and IL-10 expression in macrophages. Additionally, OA alone or FAs decreased COX-2, TNFα, IL-6, and IL-12 expression in LPS-stimulated macrophages. In the DSS murine model, oral administration of FAs reduced inflammatory parameters, decreased Escherichia coli and Enterococcus faecalis populations, and eliminated C. glabrata from the gut. Overall, these findings provide evidence that OA combined with PA exhibits anti-inflammatory and antifungal properties.

Ethnobotany, phytochemistry, pharmacology, and conservation of the genus Calanthe R. Br. (Orchidaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

The Genus Calanthe (family Orchidaceae) consists of more than 207 species distributed in both tropical and subtropical regions. In traditional medicine, Calanthe species provide remedies against various conditions such as arthritis, rheumatism, traumatic injuries, snake-bites, abdominal discomfort, nose bleeding, common colds, ulcers, chronic coughs, and others. Some species are also used as aphrodisiacs, tonics, and as pain relievers on joints and toothaches.

AIM OF THE REVIEW

This review provides comprehensive information on the herbal uses, chemical components, pharmacological activities, and conservation of Calanthe, which might be useful in the future development of potent herbal medicines and facilitate the enactment of better conservation strategies.

MATERIALS AND METHODS

Relevant information was obtained from online databases including SCI-Finder, Google Scholar, Web of Science, Science Direct, PubMed, Springer, IOP Science, and other web sources such as PubChem, The Plant List, and World Flora Online. Books, Ph.D. and MSc dissertations were used for unpublished literature. Information from Chinese literature was obtained from the CNKI database.

RESULTS

In total, 19 species of the genus Calanthe have been reported to be used in traditional medicine in different countries of Asia. A total of 265 chemical compounds from different chemical classes including, alkaloids, terpenoids, phenolic compounds and phenolic derivatives, phenanthrenes, and others, have been identified from Calanthe species. Calanquinone A isolated from C. arisanensis has been reported to exhibit antitumor activity against six malignant cell lines. Other bioactive compounds from Calanthe with pharmacological activity include phenanthrenes, phenanthrenequinones, 6'-O-β-D-apiofuranosylindican, 4H-Pyran-4one, 2, 3-dihydro-3,5 dihydroxy-6-methyl, and calanthoside. These compounds exhibit valuable biological properties such as hair restoration, anticancer activity, anti-inflammatory and antiarthritic activity, antidiabetic and hepatoprotective potency, antiplatelet aggregation action, and antibacterial and antifungal activities. Some Calanthe species, including C. ecallosa and C. yuana, are endangered in the IUCN red list. The high risk of extinction is attributed to illegal trade and unsustainable harvesting and utilization.

CONCLUSIONS

This review summarizes the herbal uses, chemical components, biological activity, and conservation of Calanthe. The pharmacological studies on this genus are limited; thus, extensive research on the toxicology, pharmaceutical standardization, and mechanism of action of the isolated bioactive compounds are needed. Since some species of Calanthe are listed as endangered, stringent guidelines on trade, collection, and sustainable utilization of medicinal orchids should be set up to facilitate the conservation of these species.

Lactobacillus crispatus BC1 Biosurfactant Counteracts the Infectivity of Chlamydia trachomatis Elementary Bodies

Lactobacilli-derived biosurfactants (BS) have shown promising effects as antimicrobial molecules. Since Lactobacillus crispatus plays a crucial role in maintaining vaginal eubiosis, BS from this species could represent novel therapeutic agents to counteract sexually transmitted pathogens, such as Chlamydia trachomatis (CT). The aim of the present study was to assess the inhibitory effects of a BS produced by the vaginal strain L. crispatus BC1 on the infectivity of CT elementary bodies (EBs). For concentrations ranging between 1 and 0.5 mg/mL at 60-min contact time, L. crispatus BC1 BS displayed a highly significant anti-CT activity, with about 50% reduction of EB infectivity towards HeLa cells. To identify the components responsible for chlamydial inhibition, a panel of selected fatty acids, including those present in BS lipopeptidic structure, was tested against CT EBs. Pentadecanoic acid, myristic acid, β-hydroxy-myristic acid, and β-hydroxy-palmitic acid were able to significantly reduce EBs infectivity up to 5–0.5 µg/mL, concentrations that resulted to be non-toxic for HeLa cells. These data can contribute to the understanding of the biological role of lactobacilli in the vaginal niche, as well as to promote the application of their produced BS as an innovative and antibiotic-sparing anti-chlamydial strategy.

Mucoadhesive Electrospun Fibre-Based Technologies for Oral Medicine

Oral disease greatly affects quality of life, as the mouth is required for a wide range of activities including speech, food and liquid consumption. Treatment of oral disease is greatly limited by the dose forms that are currently available, which suffer from short contact times, poor site specificity, and sensitivity to mechanical stimulation. Mucoadhesive devices prepared using electrospinning offer the potential to address these challenges by allowing unidirectional site-specific drug delivery through intimate contact with the mucosa and with high surface areas to facilitate drug release. This review will discuss the range of electrospun mucoadhesive devices that have recently been reported to address oral inflammatory diseases, pain relief, and infections, as well as new treatments that are likely to be enabled by this technology in the future.

Medium-Chain Fatty Acids Released from Polymeric Electrospun Patches Inhibit Candida albicans Growth and Reduce the Biofilm Viability

Oral candidiasis is a very common oral condition among susceptible individuals, with the main causative organism being the fungus Candida albicans. Current drug delivery systems to the oral mucosa are often ineffective because of short drug/tissue contact times as well as increased prevalence of drug-resistant Candida strains. We evaluated the potency of saturated fatty acids as antifungal agents and investigated their delivery by novel electrospun mucoadhesive oral patches using agar disk diffusion and biofilm assays. Octanoic (C8) and nonanoic (C9) acids were the most effective at inhibiting C. albicans growth on disk diffusion assays, both in solution or when released from polycaprolactone (PCL) or polyvinylpyrrolidone/RS100 (PVP/RS100) electrospun patches. In contrast, dodecanoic acid (C12) displayed the most potent antifungal activity against pre-existing C. albicans biofilms in solution or when released by PCL or PVP/RS100 patches. Both free and patch-released saturated fatty acids displayed a significant toxicity to wild-type and azole-resistant strains of C. albicans. These data not only provide evidence that certain saturated fatty acids have the potential to be used as antifungal agents but also demonstrate that this therapy could be delivered directly to Candida-infected sites using electrospun mucoadhesive patches, demonstrating a potential new therapeutic approach to treat oral thrush.

A novel trehalosamine isolated from Bacillus amyloliquefaciens and its antibacterial activities

Bacillus amyloliquefaciens has been widely used as a probiotic in the field of biological control,and its antibacterial compounds plays an important role in the prevention and control of plant, livestock and poultry diseases. It has the advantages of green, safe and efficiency. This study aims to separate and purify active ingredient from Bacillus amyloliquefaciens GN59 and study its antibacterial activity. A novel compound was isolated from GN59 by column chromatography on silica gel and HPLC purification. The chemical structure was identified as α-D-glucopyranosyl-(1 → 1')-3'-amino-3'-deoxy-β-D-glucopyranoside (a,β-3-trehalosamine) on the basis of spectroscopic analysis. This is the first report about a,β-3-trehalosamine isolated from biological resources on an antibiotic activity against pathogenic bacterium. The 3'-neotrehalosamine displayed antibacterial activity across a broad spectrum of microorganisms, including different gram-positive and gram-negative bacteria, with minimal inhibitory concentration (MIC) values ranging from 0.5 to 0.7 mg/mL. The results indicated that the 3'-neotrehalosamine from GN59 might be a potential candidate for bactericide.

Antimicrobial efficacy of medium chain fatty acids as root canal irrigants: An in vitro study

BACKGROUND

Enterococcus faecalis and Candida albicans are the microbes that are most resistant to elimination by disinfecting agents and are the causative agents for reinfection of the root canal treated teeth. Medium chain fatty acids (MCFAs), which are the main components of coconut oil, are proven antimicrobial agents. Thus, the aim of this study was to evaluate their antimicrobial efficacy against E. faecalis and C. albicans.

METHODOLOGY

Ninety extracted single-rooted mandibular premolar teeth were decoronated, biomechanically prepared, autoclaved, and divided into three groups (n = 30): Group A (inoculated with E. faecalis), Group B (inoculated with C. albicans), and Group C (control group). Each group was again subdivided into three groups (n = 10) and irrigated with lauric acid (LA), decanoic acid (DA), and octanoic acid, respectively, for 5 min. Paper point samples were taken from canal walls and transferred into Brain Heart Infusion broth and potato dextrose broth and placed in an incubator at 37°C. The appearance of tubidity was checked at 24, 48, 72, and 96 h using direct contact test. The data were then statistically analyzed using the analysis of variance and Tukey honestly significant difference post hoc tests.

RESULTS

Among the three MCFAs, LA showed the maximum inhibitory against E. faecalis at 24 h and the inhibitory activity decreased considerably at 48, 72, and 96 h. DA was the most effective against C. albicans with a maximum inhibition at 48 h. DA also showed significant substantivity at 72 and 96 h.

CONCLUSION

Within the limitations of this study, it can be concluded that MCFAs show promising antimicrobial efficacy against E. faecalis and C. albicans.