Altered redox status, DNA damage and modulation of L-tryptophan metabolism contribute to antimicrobial action of curcumin

Oluyomi Stephen Adeyemi; Joy Ihuoma Obeme-Imom; Benjamin Oghenerobor Akpor; Damilare Rotimi; Gaber El-Saber Batiha; Akinyomade Owolabi

doi:10.1016/j.heliyon.2020.e03495

Altered redox status, DNA damage and modulation of L-tryptophan metabolism contribute to antimicrobial action of curcumin

Heliyon. 2020 Mar 3;6(3):e03495. doi: 10.1016/j.heliyon.2020.e03495. eCollection 2020 Mar.

Authors

Oluyomi Stephen Adeyemi^{1

2}, Joy Ihuoma Obeme-Imom³, Benjamin Oghenerobor Akpor⁴, Damilare Rotimi³, Gaber El-Saber Batiha⁵, Akinyomade Owolabi⁴

Affiliations

¹ Laboratory of Theoretical and Computational Biophysics, Ton Duc Thang University, Ho Chi Minh City, Viet Nam.
² Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Viet Nam.
³ Department of Biochemistry, Medicinal Biochemistry, Nanomedicine & Toxicology Laboratory, Landmark University, PMB 1001, Omu-Aran, 251101, Nigeria.
⁴ Department of Microbiology, Landmark University, PMB 1001, Omu-Aran, 251101, Nigeria.
⁵ Department of Pharmacology and Therapeutics, Faculty of Veterinary Medicine, Damanhour University, Egypt.

Abstract

Identification and development of newer and better antimicrobials from natural products represent ongoing research efforts by many investigators. Curcumin is a polyphenol commonly found in the plant Curcuma longa (better known as turmeric). It has been reported to possess several bioactivities including antioxidant, anti-cancer, anti-inflammatory, anti-diabetic, anti-fibrotic, and antimicrobial properties. However, little is known about the antimicrobial mode of action of curcumin, thus undermining its prospects as an alternative antimicrobial agent. In this study, we investigated the mechanism of antimicrobial action by curcumin. The mechanism of inhibition was evaluated in representatives of Gram negative (Escherichia coli) and Gram positive (Staphylococcus aureus) bacteria isolates, treated with either curcumin singly or in combination with ascorbic acid (1000 μg/mL). Results showed that curcumin has broad antimicrobial capacity. In addition, curcumin only and/or co-treatment with ascorbic acid caused lipid peroxidation in S. aureus and E. coli, and by extension led to DNA damage, indicative of oxidative stress. It is plausible that the oxidative might be related to the activation of the kynurenine pathway in S. aureus but not in E. coli. Furthermore, curcumin exposure led to elevated total antioxidant capacity (TAC) and level of total thiol, but decreased nitric oxide level in the bacteria isolates. Together, the findings suggest that oxidative stress and DNA damage might be partly responsible for the antimicrobial action of curcumin.

Keywords: Antimicrobials; Biochemistry; Medicinal biochemistry; Microbial infection; Microbiology; Natural product chemistry; Natural products; Organic chemistry; Polyphenols; Toxicology.