Evaluation of the Antimicrobial and Cytotoxic Activity of Cultivated Valeriana officinalis

Abstract

Drug resistance refers to the reduction in the effectiveness of a drug in treating a disease or improving the stability of symptoms. It can occur in various types of pathogens, including bacteria, parasites, viruses, fungi, and cancer cells. This experimental study was conducted between 2018 and 2019 in an area with an annual mean rainfall of 130mm. The sowing date was September 10th, and 2-3 seeds were planted per cell. MTT assays (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide) were used to determine the percentage of viability in adenocarcinomic human alveolar basal epithelial cells (A549) and Medical Research Council cell strain 5 (MRC5) cell lines incubated with methanolic extract and valerenic acid for 48 hr. The methanol extract was prepared by adding 1000 mg of rhizomes to 100 mL of methanol, followed by sonication for 30 minutes, stirring, and centrifugation at 4000 rpm for 10 minutes. Minimum inhibitory concentration (MIC) and agar gel diffusion were used to assess the antimicrobial activity of the methanol extract of valerian against two important pathogenic microorganisms, Staphylococcus aureus and Candida albicans. However, valerenic acid did not reveal antimicrobial activity at doses of 200, 100, 50, 25, 12.5, and 6.25 µg/mL. The methanolic extract of V. officinalis contains high quantities of sesquiterpenes, specifically valerenic acid, which did not show cytotoxic effects on A549 and MRC5 cell lines as assessed by the MTT assay. In vivo evaluation of the extract in mice and guinea pigs did not reveal any toxic effects based on histopathological and clinical symptom assessments. Our study confirms that Valeriana officinalis has dose-dependent potential to improve existing treatment approaches for Staphylococcus aureus and Candida albicans infections.