Evaluation and Comparison of the Effects of Mature Silkworm (Bombyx mori) and Silkworm Pupae Extracts on Schwann Cell Proliferation and Axon Growth: An In Vitro Study

Mohammad Hossein Khosropanah; Masoumeh Majidi Zolbin; Abdol-Mohammad Kajbafzadeh; Leili Amani; Ismaeil Harririan; Ashkan Azimzadeh; Touraj Nejatian; Mahdi Alizadeh Vaghsloo; Zahra Hassannejad

doi:10.5812/ijpr-133552

Evaluation and Comparison of the Effects of Mature Silkworm (Bombyx mori) and Silkworm Pupae Extracts on Schwann Cell Proliferation and Axon Growth: An In Vitro Study

Iran J Pharm Res. 2023 Feb 21;21(1):e133552. doi: 10.5812/ijpr-133552. eCollection 2022 Dec.

Authors

Mohammad Hossein Khosropanah¹, Masoumeh Majidi Zolbin², Abdol-Mohammad Kajbafzadeh², Leili Amani³, Ismaeil Harririan⁴, Ashkan Azimzadeh², Touraj Nejatian⁵, Mahdi Alizadeh Vaghsloo^{1

6}, Zahra Hassannejad²

Affiliations

¹ Department of Traditional Medicine, School of Persian Medicine, Tehran University of Medical Sciences, Tehran, Iran.
² Pediatric Urology and Regenerative Medicine Research Center, Children's Medical Center, Gene, Cell and Tissue Research Institute, Tehran University of Medical Sciences, Tehran, Iran.
³ Department of Traditional Pharmacy, School of Persian Medicine, Tehran University of Medical Sciences, Tehran, Iran.
⁴ Department of Pharmaceutical Biomaterials, Medical Biomaterials Research Center, Tehran University of Medical Sciences, Tehran, Iran.
⁵ AFHEA Prosthodontics and ORE University College London, London, England.
⁶ Persian Medicine Network, Universal Scientific Education and Research Network, Tehran, Iran.

Abstract

Background: Silkworm products were first used by physicians more than 8500 years ago, in the early Neolithic period. In Persian medicine, silkworm extract has several uses for treating and preventing neurological, cardiac, and liver diseases. Mature silkworms (Bombyx mori) and their pupae contain a variety of growth factors and proteins that can be used in many repair processes, including nerve regeneration.

Objectives: The study aimed to evaluate the effects of mature silkworm (Bombyx mori), and silkworm pupae extract on Schwann cell proliferation and axon growth.

Methods: Silkworm (Bombyx mori) and silkworm pupae extracts were prepared. Then, the concentration and type of amino acids and proteins in the extracts were evaluated by Bradford assay, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and liquid chromatograph-mass spectrometer (LC-MS/MS). Also, the regenerative potential of extracts for improving Schwann cell proliferation and axon growth was examined by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay, electron microscopy, and NeuroFilament-200 (NF-200) immunostaining.

Results: According to the results of the Bradford test, the total protein content of pupae extract was almost twice that of mature worm extract. Also, SDS-PAGE analysis revealed numerous proteins and growth factors, such as bombyrin and laminin, in extracts that are involved in the repair of the nervous system. In accordance with Bradford's results, the evaluation of extracts using LC-MS/MS revealed that the number of amino acids in pupae extract was higher than in mature silkworm extract. It was found that the proliferation of Schwann cells at a concentration of 0.25 mg/mL in both extracts was higher than the concentrations of 0.01 and 0.05 mg/mL. When using both extracts on dorsal root ganglion (DRGs), an increase in length and number was observed in axons.

Conclusions: The findings of this study demonstrated that extracts obtained from silkworms, especially pupae, can play an effective role in Schwann cell proliferation and axonal growth, which can be strong evidence for nerve regeneration, and, consequently, repairing peripheral nerve damage.

Keywords: Axon Growth; Dorsal Root Ganglia; Pupae Extract; Schwann Cell Proliferation; Silkworm (Bombyx mori) Extract.