Tropical Journal of Pharmaceutical Research
Pharmacotherapy Group, Faculty of Pharmacy, University of Benin, Benin City, Nigeria
Vol. 13, No. 11, 2014, pp. 1815-1823
Bioline Code: pr14250
Full paper language: English
Document type: Research Article
Document available free of charge
Tropical Journal of Pharmaceutical Research, Vol. 13, No. 11, 2014, pp. 1815-1823
© Copyright 2014 - Tropical Journal of Pharmaceutical Research
Metabolites from Actinomyces Strain H6552 Extract Inhibit Transforming Growth Factor-Mediated Pulmonary Fibrosis|
Koh, Rhun Yian; Lim, Chooi Ling; Ho, Coy Choke; Uhal, Bruce David; Abdullah, Maha; Vidyadaran, Sharmili & Seow, Heng Fong
Purpose: To evaluate the effects of H6552 extract in inhibiting transforming growth factor (TGF)-
mediated pulmonary fibrosis in vitro and in vivo.
Methods: Maximum-nontoxic dose (MNTD) of Actinomyces H6552 extract was determined using 3-
(4,5-dimethylthiazol-2-yl)-2,5-diphhenyltetrazolium bromide (MTT) assay. Effect of the extract on IMR-
90 lung fibroblasts proliferation was determined by calculating the population doubling time (PDT).
Collagen gel contraction assay was carried out to determine cell contractility while α-smooth muscle
actin (SMA) level in cells was evaluated by quantitative real-time polymerase chain reaction (PCR) and
immunostaining methods. A bleomycin-induced ICR mouse model was used in the study to determine
the effect of the extract in vivo. The animals received treatments in two regimes: early treatment in
which treatment was given on Day 0 and delayed treatment with treatment on Days 5 and 10. The
animals were sacrificed on Day 14 and the lungs removed for histopathological assessment.
Results: The MNTD of the H6552 extract was 1625 ± 459.62 μg/ml. H6552 extract significantly reduced
TGF- β-mediated cell proliferation, gel contraction and α-SMA expression. PDT was increased up to
83.84 % in the treated cells. Gel contraction was inhibited by the addition of 1000 μg/ml of H6552
extract. Immunostaining results revealed negligible α-SMA antibody staining after H6552 extract
treatment at 500 μg/ml. The extract also inhibited lung injury (54 % reduction in Ashcroft score) when
early treatment was provided. Delayed treatment with the extract did not show any significant changes
in the animals.
Conclusion: H6552 extract inhibited TGF-β-induced pulmonary fibrosis and elucidation of its bioactive
metabolites may yield a potential agent to treat the disease.
Actinomyces H6552; Transforming growth factor-β; Cell contractility; α-Smooth muscle actin; Pulmonary fibrosis
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