Melanin pigment of Streptomyces puniceus RHPR9 exhibits antibacterial, antioxidant and anticancer activities

PLoS One. 2022 Apr 25;17(4):e0266676. doi: 10.1371/journal.pone.0266676. eCollection 2022.

Abstract

The present study reveals the production of dark, extracellular melanin pigment (386 mg/L) on peptone yeast extract iron agar medium by Streptomyces puniceus RHPR9 using the gravimetric method. UV-Visible, Fourier Transform Infrared (FTIR), and Nuclear Magnetic Resonance (1H) (NMR) spectroscopy confirmed the presence of melanin. Extracted melanin showed antibacterial activity against human pathogens such as Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli except for Klebsiella pneumoniae. A potent free radical scavenging activity was observed at 100 μg/mL of melanin by the DPPH method with a concentration of 89.01±0.05% compared with ascorbic acid 96.16±0.01%. Antitumor activity of melanin was evaluated by MTT assay against HEK 293, HeLa, and SK-MEL-28 cell lines with IC50 values of 64.11±0.00, 14.43±0.02, and 13.31±0.01 μg/mL respectively. Melanin showed maximum anti-inflammatory activity with human red blood cells (hRBC) (78.63 ± 0.01%) and minimum hemolysis of 21.37±0.2%. The wound healing potential of the pigment was confirmed on HeLa cells, cell migration was calculated, and it was observed that cell migration efficiency decreased with an increase in the concentration of melanin. To our knowledge, this is the first evidence of melanin produced from S. puniceus RHPR9 that exhibited profound scavenging, anti-inflammatory and cytotoxic activities.

Publication types

  • Research Support, Non-U.S. Gov't
  • Retracted Publication

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Antioxidants* / metabolism
  • HEK293 Cells
  • HeLa Cells
  • Humans
  • Melanins* / metabolism
  • Streptomyces

Substances

  • Anti-Bacterial Agents
  • Antioxidants
  • Melanins

Supplementary concepts

  • Streptomyces puniceus

Grants and funding

This work was funded by Taif University Researchers Supporting Project Number (TURSP-2020/208), Taif University, Saudi Arabia, and RMC, Universiti Teknologi Malaysia (UTM), Malaysia, through grant No. R.J130000.7609.4C336 and R.J130000.7609.4C359. The funder had a role in the study design, analysis, and preparation of the manuscript.