In vitro effects of phytogenic feed additive on Piscirickettsia salmonis growth and biofilm formation.

Piscirickettsiosis is the main cause of mortality in salmonids of commercial importance in Chile, which is caused by Piscirickettsia salmonis, a Gram-negative, γ-proteobacteria that can produce biofilm as one of its virulence factors. The Chilean salmon industry uses large amounts of antibiotics to control piscirickettsiosis outbreaks, which has raised concern about its environmental impact and the potential to induce antibiotic resistance. Thus, the use of phytogenic feed additives (PFA) with antibacterial activity emerges as an interesting alternative to antimicrobials. Our study describes the antimicrobial action of an Andrographis paniculate-extracted PFA on P. salmonis planktonic growth and biofilm formation. We observed complete inhibition of planktonic and biofilm growth with 500 and 400 µg/mL of PFA for P. salmonis LF-89 and EM-90-like strains, respectively. Furthermore, 500 µg/mL of PFA was bactericidal for both evaluated bacterial strains. Sub-inhibitory doses of PFA increase the transcript levels of stress (groEL), biofilm (pslD), and efflux pump (acrB) genes for both P. salmonis strains in planktonic and sessile conditions. In conclusion, our results demonstrate the antibacterial effect of PFA against P. salmonis in vitro, highlighting the potential of PFA as an alternative to control Piscirickettsiosis.

Andrographis paniculata decreases fatigue in patients with relapsing-remitting multiple sclerosis: a 12-month double-blind placebo-controlled pilot study.

BACKGROUND: Andrographis paniculata (A. paniculata), a medicinal plant, has shown anti-inflammatory, neuroprotective and antifibrotic effects in animal models as well as clinical efficacy in different studies, including an anti-fatigue effect in autoimmune diseases such as rheumatoid arthritis. In multiple sclerosis (MS), fatigue is rated as one of the most common and disabling symptoms. In the present trial, we investigated the effect of A. paniculata on relapse rate and fatigue in relapsing-remitting MS (RRMS) patients receiving interferon beta. METHODS: A randomised double-blind placebo-controlled trial assessed the effects of 170 mg of A. paniculata dried extract tablet b.i.d. p.o. on relapse rate and fatigue using the Fatigue Severity Scores (FSS) over 12 months in RRMS patients receiving interferon. The Expanded Disability Status Scale (EDSS) score, inflammatory parameters and radiological findings were also investigated. Twenty-five patients were enrolled, and twenty-two patients were ultimately analysed and randomised to the active or placebo group. RESULTS: Patients treated with A. paniculata showed a significant reduction in their FSS score as compared to the placebo, equivalent to a 44 % reduction at 12 months. No statistically significant differences were observed for relapse rate, EDSS or inflammatory parameters, with a trend in reducing new lesions among the A. paniculata group. One patient in the A. paniculata group presented with a mild and transient skin rash, which was alleviated with anti-histamine treatment for three weeks. CONCLUSION: A. paniculata was well tolerated in patients and no changes in clinical parameters were observed. A. paniculata significantly reduces fatigue in patients with RRMS receiving interferon beta in comparison to placebo and only interferon beta treatment. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02280876 ; Trial registration date: 20.10.2014.