Antibacterial Activity of the Mixed Systems Containing 1,2-Dodecanediol against <i>Staphylococcus aureus</i> and <i>Staphylococcus epidermidis</i>

Abstract

S. epidermidis owing to its hydrophobic long alkyl chain.The antimicrobial behavior of 1,2-alkanediol in mixed systems with other components is unclear as only a single antimicrobial agent was added in these evaluation systems in previous study. However, various antimicrobial ingredients such as acids, salts, sebum and preservatives can coexist on the surface of the skin, if cosmetic and cleansing products containing 1,2-alkanediol are applied to keep the body clean and healthy 12 14 . These substances may affect the antimicrobial properties against skin bacteria. The antibacterial ability against S. aureus or E. coli was improved when 1,2-alkanediol was mixed with dipropylene glycol or phenoxyethanol 15,16 . Therefore, the antimicrobial behavior in mixed systems, including multiple antimicrobial agents, is important for the preparation of effective antimicrobial systems. The checkerboard method is useful for evaluating Abstract: 1,2-Alkanediols are characteristic cosmetic ingredients because these moisturizers exhibit the antibacterial activity against Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis). However, the antimicrobial behavior in mixed systems containing several active ingredients is unclear because previous reports focus on an antibacterial system containing only 1,2-alkanediol. In this study, the minimal inhibitory concentration (MIC) and the fractional inhibitory concentration (FIC) were evaluated for 1,2-dodecanediol/lactic acid, 1,2-dodecanediol/myristic acid, 1,2-dodecanediol/methylparaben, and 1,2-dodecanediol/isopropyl methylphenol mixed systems to show the effect of the addition of other antimicrobial components to 1,2-dodecanediol. The antibacterial property of 1,2-dodecanediol/lactic acid mixed system was almost similar compared to 1,2-dodecanediol monomeric system. On the other hand, the antimicrobial activity of 1,2-dodecanediol against S. epidermidis was inhibited in the 1,2-dodecanediol/ myristic acid mixed system. Because the selective antimicrobial activity of myristic acid against S. aureus was demonstrated in the mixed system. The present findings are useful for designing formulations of cosmetics and body cleansers containing 1,2-dodecanediol.

Antibacterial Effect of Oral Care Gel-Containing Hinokitiol and 4-isopropyl-3-methylphenol Against Intraoral Pathogenic Microorganisms

“…[34] IPMP is typical of preservatives and bactericidal ingredients in cosmetics and is used in many oral care products. [35,36] These facts are consistent with the observation that HO tended to have higher antibacterial activity than RC.…”

Antimicrobial effect of oral care gel containing hinokitiol and 4-isopropyl-3-methylphenol against intraoral pathogenic microorganisms

“…IPMP is a typical preservative and bactericidal constituent in cosmetics and is used in commercial oral care products [41]. Phenolic compounds such as IPMP, phenoxyethanol, and ortho-phenylphenol are often thought to exhibit antimicrobial activity by damaging cell membranes and changing the membrane structure and function [42]. These facts are consistent with the observation that HO had higher antimicrobial activity than RC.…”

Structure–activity relationship on selective antibacterial activity of nonionic surfactants

“…Previously, Yamamoto et al evaluated the antibacterial activity of fatty acids and their metal salts against Staphylococcus aureus ( S. aureus ) and Staphylococcus epidermidis ( S. epidermidis ), and found that palmitoleic acid, its calcium salts and formulations containing them had selective antibacterial activity against S. aureus (Watanabe et al, 2019; Watanabe et al, 2021; Yamamoto et al, 2015, b; Yamamoto et al, 2017). The antibacterial activity of 1,2‐alkanediols was stronger if the alkyl chain length was longer (Okukawa et al, 2019; Okukawa et al, 2021, b). Selectivity for S. aureus is important because S. aureus causes atopic dermatitis and skin roughness, whereas S. epidermidis is beneficial because it helps maintain a healthy epidermis and enhances innate immunity (Kobayashi et al, 2015; Naik et al, 2015; Novick, 2003).…”