Acidic Electrolyzed Water Inhibits the Viability of Gardnerella spp. via Oxidative Stress Response

Chongyu Zhao; Yu Chen; Lvfen Gao; Jue Huang; Xiurou Yang; Luowei Pei; Zhangying Ye; Linyan Zhu

doi:10.3389/fmed.2022.817957

Acidic Electrolyzed Water Inhibits the Viability of Gardnerella spp. via Oxidative Stress Response

Front Med (Lausanne). 2022 Feb 25:9:817957. doi: 10.3389/fmed.2022.817957. eCollection 2022.

Authors

Chongyu Zhao^{1

2}, Yu Chen¹, Lvfen Gao³, Jue Huang¹, Xiurou Yang¹, Luowei Pei⁴, Zhangying Ye⁴, Linyan Zhu¹

Affiliations

¹ Department of Pharmacology, School of Medicine, Jinan University, Guangzhou, China.
² Department of Urology, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
³ Department of Obstetrics and Gynecology, The First Affiliated Hospital, Jinan University, Guangzhou, China.
⁴ School of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, China.

Abstract

The vaginal microbiota, dominated by Lactobacilli, plays an important role in maintaining women's health. Disturbance of the vaginal microbiota allows infection by various pathogens such as Gardnerella spp. (GS) and related anaerobic bacteria resulting in bacterial vaginosis (BV). At present, the treatment options for BV are extremely limited. Treatment of antibacterial drugs and vaginal acidification are the two primary therapeutic methods. Acid electrolyzed water (AEW) is known to inactivate microorganisms and is considered a medical application in recent years. Studies have found that Lactobacillus acidophilus (LA) probiotics helps to inhibit GS-induced BV. Our study took GS and LA as the research object, which aims to explore AEW as a potential alternative therapy for BV and its underlying mechanisms. We first obtained the pH of AEW (3.71-4.22) close to normal vaginal pH (3.8-4.5) to maintain normal vaginal acidification conditions. Plate counting experiments showed that AEW (pH: 4.07, ORP: 890.67, ACC: 20 ppm) (20 ppm) could better inhibit the viability of GS but had a more negligible effect on LA. Then, we preliminarily explored the possible mechanism of AEW anti-GS using cell biology experiments and transmission electron microscopy. Results showed that the membrane permeability was significantly increased and the integrity of cell membrane was destroyed by AEW in GS than those in LA. AEW also caused protein leakage and cell lysis in GS without affecting LA. Meanwhile, AEW induced a number of reactive oxygen species (ROS) production in GS, with no obvious LA changes. Finally, we found that 20 ppm AEW exhibited excellent antibacterial effect on the vaginal secretions of women diagnosed with BV by Amsel criteria and sialic acid plum method. Taken together, our findings manifest that 20 ppm AEW has an excellent antibacterial effect in GS with less effect on LA, which might be expected to become a potential therapy for BV.

Keywords: Gardnerella spp.; Lactobacillus acidophilus; acidic electrolyzed water; bacterial vaginosis (BV); reactive oxygen species.