Biology subjects

Frederich, M.

Publications and source records attributed to Frederich, M..

3 recordsLinked to original sources

bioRxiv2026

Synergistic induction of a lethal Autosis-to-Apoptosis switch by phytocannabinoids and β-Caryophyllene in Triple-Negative Breast Cancer Cells

BackgroundTriple-negative breast cancer (TNBC) presents significant therapeutic limitations due to its aggressive heterogeneity and the rapid emergence of adaptive resistance to apoptosis-based regimens. Addressing these challenges requires polypharmacological strategies capable of modulating multiple signalling networks simultaneously. While the Cannabis sativa phytocomplex offers a vast chemical space for multi-target intervention, the quantitative pharmacological basis of its synergistic interactions remains largely uncharacterised. PurposeThis study aimed to deconstruct the synergistic landscape of high-purity phytocannabinoids (CBD, CBG, CBD-A) in combination with the sesquiterpene {beta}-caryophyllene (BCP) against TNBC, using MDA-MB-231 as a primary model and Hs578T as a validation line. MethodsGrowth Rate (GR) inhibition metrics and the SynergyFinder+ framework were used to map pharmacological interactions across four reference models. Subcellular dynamics and phenotypic transitions were characterised by high-resolution label-free holotomographic microscopy combined with live-cell kinetic imaging and single-cell fate mapping. ResultsTwo highly potent synergistic clusters were identified for CBD-CBG-BCP combinations, with ZIP, HSA, and Bliss synergy scores exceeding 65. CBD-A exhibited minimal interaction potential and was excluded from ternary studies. GR-based quantification further revealed that these combinations produced net cytotoxicity (GR < 0) at sub-IC concentrations of each component. Single-cell fate mapping by holotomographic microscopy identified a temporally ordered death programme: an initial phase of extensive cytoplasmic vacuolisation associated with focal perinuclear space swelling and progressive nuclear compression, morphological hallmarks of autosis, which is followed by a transition to apoptotic execution. The autotic nature of the primary death phase was confirmed by pharmacological rescue with digoxin, a selective inhibitor of the Na,K-ATPase. To the best of our knowledge, this sequential engagement of autosis followed by apoptotic execution represents the first documented instance of such a two-stage death programme in any cellular model. ConclusionThese findings provide robust evidence that specific phytocannabinoid-terpene ratios engage a Na,K-ATPase-regulated autotic programme as an upstream commitment step, followed by apoptotic execution, effectively circumventing the caspase-independent resistance mechanisms characteristic of TNBC. This study establishes a rational, quantitatively validated framework for transitioning from empirical botanical use to evidence-based, multi-target cannabinoid polypharmacology in aggressive breast cancer.

pharmacology and toxicology↗

bioRxiv2022

Lunaemycins, new cyclic hexapeptide antibiotics from the cave moonmilk-dweller Streptomyces lunaelactis MM109

Streptomyces lunaelactis strains have been isolated from moonmilk deposits which are calcium carbonate speleothems used for centuries in traditional medicine for their antimicrobial properties. Genome mining revealed that these strains are a remarkable example of a Streptomyces species with huge heterogeneity regarding their content in biosynthetic gene clusters (BGCs) for specialized metabolite production. BGC 28a is one of the cryptic BGCs that is only carried by a subgroup of S. lunaelactis strains for which in silico analysis predicted the production of nonribo-somal peptide antibiotics containing the non-proteogenic amino acid piperazic acid (Piz). Comparative metabolomics of culture extracts of S. lunaelactis strains either or not holding BGC 28a combined with MS/MS-guided peptidogenomics and 1H/13C NMR allowed to identify the cyclic hexapeptide with the amino acid sequence (D-Phe)-(L-HO-Ile)-(D-Piz)-(L-Piz)-(D-Piz)-(L-Piz), called lunaemycin A, as the main compound synthesized by BGC 28a. Molecular networking further identified 18 additional lunaemycins, 14 of them having their structure elucidated by HRMS/MS. Antimicrobial assays demonstrated a huge bactericidal activity of lunaemycins against Gram-positive bacteria including multi-drug resistant clinical isolates. Our work demonstrates how accurate in silico analysis of a cryptic BGC can highly facilitate the identification, the structural elucidation, and the bioactivity of its associated specialized metabolites.

microbiology↗

bioRxiv2017

Development of an HPTLC method for determination of hypoglycin A in aqueous extracts of seedlings and samaras of Acer species

Hypoglycin A (HGA) is a toxin contained in seeds of the sycamore maple tree (Acer pseudoplatanus). Ingestion of this amino acid causes equine atypical myopathy (AM) in Europe. Another variety, A. negundo, is claimed to be present where AM cases were reported in the US. For unknown reasons, occurrence of this disease has increased. It is important to define environmental key factors that may influence toxicity of samaras from Acer species. In addition, the content of HGA in seedlings needs to be determined since AM outbreaks, during autumn period when the seeds fall but also during spring when seeds are germinating. The present study aims to validate a reliable method using high performance thin layer chromatography for determination and comparison of HGA in samaras and seedlings.\n\nThe working range of the method was between 20 g HGA to 408 g HGA per ml water, corresponding to 12 - 244 mg/kg fresh weight or 40 - 816 mg/kg dry weight, taking into account of an arbitrary average dry matter content of 30%. Instrumental limit of detection and limit of quantification were of 10 g HGA/ml and 20 g HGA/ml water, respectively. Instrumental precision was 4% (RSD on 20 repeated measurements) while instrumental accuracy ranged between 86% and 121% of expected value. The HGA recovery of the analytical method estimated from spiked samaras and seedlings samples ranged between 63 and 103%. The method was applied to 9 samples of samaras from Acer pseudoplatanus, A. platanoides and A. campestre and 5 seedlings samples from A. pseudoplatanus. The results confirm detection of HGA in samaras from A. pseudoplatanus and the absence of detection in samaras of other tested species. They also suggest that detected levels of HGA are highly variable. This confirmed the suitability of the method for HGA detection in samaras or seedling.

pharmacology and toxicology↗