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Updated: Jun 10, 2026
07:37
An Integrated Raman Spectroscopy and Mass Spectrometry Platform to Study Single-Cell Drug Uptake, Metabolism, and Effects
Published on: January 9, 2020
Use ofBacillus stearothermophilus as a model to study tamoxifen-membrane interactions
C Luxo1, A S Jurado, J B Custo Dio
1Laborato rio de Microbiologia, Faculdade de Farma cia, Coura; Centro de Neurocie^ncias, Universidade de Coimbra, 3000, Coimbra, Portugal.
Summary
Tamoxifen (TAM) disrupts bacterial cell membranes, inhibiting growth and viability in Bacillus stearothermophilus. This cytostatic effect is linked to TAM
Area of Science:
- Microbiology
- Biochemistry
- Cell Biology
Background:
- Tamoxifen (TAM) is primarily known for its anti-oestrogen effects.
- Its non-genomic, cytostatic antiproliferative actions warrant further investigation.
- Bacterial cell membranes offer a model to study drug-membrane interactions.
Purpose of the Study:
- To investigate the interaction of tamoxifen (TAM) with bacterial cell membranes.
- To evaluate the cytostatic and antiproliferative effects of TAM independent of oestrogen binding.
- To explore the relationship between TAM's membrane effects and its growth inhibition.
Main Methods:
- Turbidimetric and viable cell counting to assess bacterial growth inhibition.
- Determination of TAM partition coefficients in bacterial polar lipid bilayers.
- Fluorescence probe studies (DPH, DPH-PA) to analyze membrane physical state.
Main Results:
- TAM significantly inhibits Bacillus stearothermophilus growth and reduces cell viability in a dose- and temperature-dependent manner.
- High partitioning of TAM into bacterial lipid membranes was observed, peaking at the phase transition temperature.
- TAM induced significant structural disorder in the lipid bilayer, particularly around the phase transition.
Conclusions:
- Tamoxifen exhibits direct cytostatic effects on bacteria by perturbing cell membrane structure and function.
- The observed growth inhibition is strongly correlated with TAM-induced alterations in bacterial membrane physical properties.
- Bacterial models can elucidate non-oestrogenic mechanisms of TAM action relevant to its broader biological effects.
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