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BMC Microbilogy
Springer Nature
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Abstract: |
Epothilone derivatives have been recognized as one of the most powerful anticancer drugs towards solid tumors,
for their unique affinity to bind with β-tubulin microtubule arrays, stabilizing their disassembly, causing cell death.
Sornagium cellulosum is the main source for Epothilone, however, the fermentation bioprocessing of this myxobacteria
is the main challenge for commercial production of Epothilone. The metabolic biosynthetic potency of epothilone
by Aspergillus fumigatus, an endophyte of Catharanthus roseus, raises the hope for commercial epothilone production,
for their fast growth rate and feasibility of manipulating their secondary metabolites. Thus, nutritional optimization
of A. fumigatus for maximizing their epothilone productivity under solid state fermentation process is the objective.
The highest yield of epothilone was obtained by growing A. fumigatus on orange peels under solid state fermentation
(2.2 μg/g), bioprocessed by the Plackett-Burman design. The chemical structure of the extracted epothilone
was resolved from the HPLC and LC-MS/MS analysis, with molecular mass 507.2 m/z and identical molecular fragmentation
pattern of epothilone B of S. cellulosum. The purified A. fumigatus epothilone had a significant activity
towards HepG2 (
IC50 0.98 μg/ml), Pancl (
IC50 1.5 μg/ml), MCF7 (
IC50 3.7 μg/ml) and WI38 (
IC50 4.6 μg/ml), as well
as a strong anti-tubulin polymerization activity (
IC50 0.52 μg/ml) compared to Paclitaxel (2.0 μg/ml). The effect of A.
fumigatus epothilone on the immigration ability of HepG2 cells was assessed, as revealed from the wound closure
of the monolayer cells that was estimated by ~ 63.7 and 72.5%, in response to the sample and doxorubicin, respectively,
compared to negative control. From the Annexin V-PI flow cytometry results, a significant shift of the normal
cells to the apoptosis was observed in response to A. fumigatus epothilone by ~ 20 folds compared to control cells,
with the highest growth arrest of the HepG2 cells at the G0-G1 stage.
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