Effect of neem (Azadirachta indica A. Juss) leaf extract on resistant Staphylococcus aureus biofilm formation and Schistosoma mansoni worms

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• 作者：Patrick V. Quelemes^a ; Má ; rcia L.G. Perfeito^a ; Maria A. Guimarã ; es^a ; Raimunda C. dos Santos^a ; David F. Lima^a ; ^b ; Carlos Nascimento^c ; Marcos P.N. Silva^d ; Maria José ; dos S. Soares^e ; Cristina D. Ropke^f ; Peter Eaton^a ; ^g ; Josué ; de Moraes^d ; José ; Roberto S.A. Leite^a ; ^{jrsaleite@gmail.com" class="auth_mail" title="E-mail the corresponding author}
• 关键词：AFM ; atomic force microscopy ; ATCC ; American Type Culture Collection ; AZA ; azadirachtin ; CFU ; colony forming unit ; CLSI ; Clinical and Laboratory Standards Institute ; DMSO ; dimethyl sulfoxide ; FAA ; formalin-acetic acid-alcohol solution ; FT-MS ; Fourier transform mass spectrometry ; HPLC-FT-MS ; liquid chromatography coupled to ultra-high-resolution mass spectrometry ; MIC ; minimum inhibitory concentration ; Neem EE ; neem leaf ethanolic extract ; NMR ; nuclear magnetic resonance ; PZQ ; praziquantel ; SPE
• 刊名：Journal of Ethnopharmacology
• 出版年：2015
• 出版时间：4 December 2015
• 年：2015
• 卷：175
• 期：Complete
• 页码：287-294
• 全文大小：2285 K

文摘

There are ethnopharmacological reports supporting the use of neem (Azadirachta indica A. Juss) leaf against bacterial and worm infections. However there is a lack of studies about its effect on bacterial biofilm formation and Schistosoma mansoni worms. This study reports the in vitro effects of neem leaf ethanolic extract (Neem EE) on Methicillin-resistant Staphylococcus aureus (MRSA) biofilm and planktonic aggregation formation, and against S. mansoni worms.

Materials and methods

Quantification of the Azadirachtin (AZA), thought to be one of their main compounds related to biological effects, was performed. The effect of sub-inhibitory concentrations of Neem EE on biofilm formation and planktonic aggregates of S. aureus was tested using the crystal violet dye method and atomic force microscopy (AFM) analysis, respectively. Changes in S. mansoni motor activity and death of worms were analyzed in vitro after exposition to the extract. Treated schistosomes were also examined using confocal laser scanning microscopy.

Results

50">It was observed the presence of AZA in the extract (0.14±0.02 mg/L). Testing Neem EE sub-inhibitory concentrations, a significant biofilm adherence inhibition from 62.5 µg/mL for a sensitive S. aureus and 125 µg/mL for two MRSA strains was observed. AFM images revealed that as the Neem EE concentration increases (from 250 to 1000 µg/mL) decreased ability of a chosen MRSA strain to form large aggregates. In relation of anti-schistosoma assay, the extract caused 100% mortality of female worms at a concentration of 50 µg/mL at 72 h of incubation, while 300 µg/mL at 24 h of incubation was required to achieve 100% mortality of male worms. The extract also caused significant motor activity reduction in S. mansoni. For instance, at 96 h of incubation with 100 µg/mL, 80% of the worms presented significant motor activity reduction. By the confocal microscopy analysis, the dorsal surface of the tegument of worms exposed to 300 µg/mL (male) and 100 µg/mL (female) of the extract showed severe morphological changes after 24 h of treatment.

Conclusions

Neem leaf ethanolic extract presented inhibitory effect on MRSA biofilm and planktonic aggregation formation, and anthelmintic activity against S. mansoni worms.