Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Metabolites from Actinomyces Strain H6552 Extract Inhibit Transforming Growth Factor-Mediated Pulmonary Fibrosis

Rhun Yian Koh^1,2, Chooi Ling Lim^1,2, Coy Choke Ho³, Bruce David Uhal⁴, Maha Abdullah¹, Sharmili Vidyadaran¹, Heng Fong Seow¹

¹Department of Pathology, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor; ²Department of Human Biology, School of Medicine, International Medical University, No. 126, Jalan Jalil Perkasa 19, Bukit Jalil, 57000 Kuala Lumpur; ³Biotechnology Programme, School of Science and Technology, University Malaysia Sabah, Locked Bag 2073, 88999 Kota Kinabalu, Sabah, Malaysia; ⁴Department of Physiology and Biomedical Sciences, Michigan State University, 2201 Biomedical Physical Sciences, East Lansing, MI 48837, USA.

For correspondence:- Heng Seow Email: shf@upm.edu.my Tel:+60389472387

Received: 25 February 2014 Accepted: 13 September 2014 Published: 24 November 2014

Citation: Koh RY, Lim CL, Ho CC, Uhal BD, Abdullah M, Vidyadaran S, et al. Metabolites from Actinomyces Strain H6552 Extract Inhibit Transforming Growth Factor-Mediated Pulmonary Fibrosis. Trop J Pharm Res 2014; 13(11):1815-1823 doi: 10.4314/tjpr.v13i11.7

© 2014 The authors.
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Abstract

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.

Keywords: Actinomyces H6552, Transforming growth factor-^6;, Cell contractility, ^5;-Smooth muscle actin, Pulmonary fibrosis