The in-vitro antibacterial effect of colored rice crude extracts against common bacteria associated with skin and soft-tissue infections

Abstract

Skin and soft tissue infections (SSTIs) are caused mainly by Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli bacteria. Due to the increasing emergence of bacterial resistance to existing antimicrobial agents, plants are being used as an alternative source to develop safe, effective, and inexpensive new agents for the treatment and prevention of bacterial infections. Recent studies show that Oryza sativa L., or rice, an important source of nutrients and consumed by most of the world’s population, has exhibited suppressive effects on bacterial infections. There are many varieties of rice, e.g. white, brown, black, and red; however, the relationship between rice colors and antibacterial properties remains to be elucidated. This study aimed to investigate the antibacterial activity of colored-rice crude extracts against bacteria causing SSTIs. Ethanol extraction was performed to prepare crude extracts from four different types of colored rice: Hom Nil (HN), Neaw Dum (ND), Mun Poo (MP), and Sang Yod (SY ). The paper disc diffusion method was used in this study. Minimum inhibitory concentration (MIC ) and minimum bactericidal concentration (MBC ) of colored-rice extracts were determined, and bacterial survival percentage was also examined to assess antibacterial activity. Our results revealed that colored-rice crude extracts exhibited anti-Staphylococcal action, and more notably, crude extracts of differently colored rice restricted diverse antibacterial activities. This study provides a basic understanding of antibacterial properties found in colored rice, against skin and wound pathogens. An understanding of these properties would be invaluable in the development of alternative, natural and safe methods for controlling SSTIs.