In vivo studies could not confirm in vitro prophylactic synergism between Moringa essential oil and Lactobacillus...

Aerobic vaginitis (AV) is a recently defined vaginal recurring infection, which is treated with antibiotics. However, excessive and prolonged use of antibiotics disrupts healthy vaginal microflora and leads to the emergence of antibiotic resistance among pathogens. This situation has directed researchers to explore alternative antimicrobials. The current study describes in vitro and in vivo antimicrobial efficacy and pharmaceutical interactions between plant essential oils (EOs) and five lactic acid bacteria (LABs), isolated from the healthy vagina, against E. faecalis, one of the major etiological agents of AV. In vitro experiments confirm good antimicrobial activity of both plant EOs and cell free supernatant (CFS) from LABs. Based on high antimicrobial efficacy, Moringa essential oil (MO) was selected to determine its nature of interaction with CFS of five LAB strains. Synergism was recorded between MO and CFS of L. reuteri (MT180537). To validate in vitro findings, prophylactic responses of individual and synergistic application of MO and L. reuteri (MT180537) were evaluated in an E. faecalis (MW051601) induced AV murine model. The prophylactic efficacy was evidenced by a reduction in intensity of clinical symptoms, E. faecalis (MW051601) count per vaginal tissue along with a reduction in AV associated changes in histological markers of infection in animals receiving Moringa essential oil and L. reuteri (MT180537) alone or in combination. However, significant synergism between Moringa essential oil and L. reuteri (MT180537) could not be observed. Our data confirms the importance of in vivo experiments in deducing pharmacological interactions.