Antimicrobial and Toxic Effects of Boswellia serrata Roxb. and Mentha piperita Linn. Essential Oils on Vaginal Inhabitants

Abstract

Commercial essential oils (EOs) of incense, Boswellia serrata Roxb, and mint, Mentha piperita L., were investigated against vaginal bacterial and Candida albicans isolates for antimicrobial potential and safety use. The antimicrobial activity of EOs was investigated through a double-dilution micro-plate assay. A brine shrimp assay was used for the determination of toxicity, while the determination of the chemical composition of EOs was carried out using GS–MS. Obtained minimal inhibitory (MIC) and minimal bactericidal concentration (MBC) point to the activity of mint essential oil (EO) against the multi-resistant P. aeruginosa isolate (MIC/MBC at 6.25 µL/mL), while MIC and MBC values for other isolates were reached at higher concentrations (25–50 µL/mL). According to the toxicity assay, the incense EO reached the LC50 value at 3.07 µL/mL, while mint EO showed higher toxicity at lower concentrations (0.5 µL/mL) and the LC50 could not be determined. The highest antimicrobial potential was obtained for incense against P. aeruginosa. Although the toxicity assay showed high toxicity of mint EO to the eggs of aquatic crustaceans Artemia salina, further testing of EO toxicity is proposed, for example on healthy cell-lines. According to the GC/MS spectrometry, the most represented components of mint EO were the oxygenated hydrocarbons L-menthone (20.86%) and menthol (31.86%), and they could be proposed for further antimicrobial and toxicity investigation.

Mentha piperita: Essential Oil and Extracts, Their Biological Activities, and Perspectives on the Development of New Medicinal and Cosmetic Products

“…In another study, the essential oil of M. piperita had very high activity against Pseudomonas aeruginosa, with an MIC and MBC of 6.25 µL/mL (0.625% v/v), and against Escherichia coli, with an MIC and MBC of 50 µL/mL, while the Candida strains showed an MIC and MFC in the range of 12.50 µL/mL (1.25% v/v) to 100 µL/mL (10% v/v). In accordance with the antibiotic resistance of the clinical isolates, the Gram-negative bacteria Pseudomonas aeruginosa and Escherichia coli showed multi-resistance to all of the tested antibiotics, which points to the high resistance of clinical isolates to conventional antibiotics [108].…”

“…Searching for alternative and complementary medical products from plants is a topical issue for the treatment of cancer. Therefore, there are many studies directed at the study of different plant resources in the search for anticancer active substances or active substances for cancer prevention [19,50,78,81,[108][109][110][111][112][113][114].…”

In vitro antiviral effect of ethanolic extracts from Azadirachta indica and Melia azedarach against goat lentivirus in colostrum and milk

“…Countless researchers use tests with A. salina Leach as an effective bioassay for the elucidation of lethal dosages of bioactive components present in natural products that are screened for different purposes [29][30][31][32] , owing to their speed, low cost, and reliability of results 29 . In general, a natural product is considered toxic when its lethal concentration is less than 1000 µg/mL, within 24 h 29 .…”

“…In general, a natural product is considered toxic when its lethal concentration is less than 1000 µg/mL, within 24 h 29 . It is noteworthy that this 24-h period is standard in several studies 29,[31][32][33] . However, in the present study, toxicity was observed after 48 h of incubation in all treatments.…”