The In Vitro Study of Antimicrobial, Antioxidant, Anti-inflammatory Activities and Toxicity of Semi-purified Anacardium occidentale Leaf Extract

Abstract

The most prevalence of infectious-inflammatory oral disease in adulthood, which caused by the imbalance of host-bacterial interaction, is periodontal diseases. Anacardium occidentale, A common plant in the southern part of Thailand. The previous study found antimicrobial and anti-inflammatory activities of the extract. So if the extract are more purified, it will make these effects more effective. Objective: The aim of this in vitro study was to investigate antimicrobial, antioxidant, anti-inflammatory activities and toxicity of semi-purified A. occidentale leaf extract. Material and methods: Using the Sephadex LH-20 column, the five semi- purified A. occidentale fractions were isolated (Fraction A, B, C, D, and E), and then were screened for antibacterial activity against Porphyromonas gingivalis by agar diffusion method. Two fractions that gave the widest clear zones were used to determine the minimal inhibitory concentration (MIC) by microdilution method, test their free radical scarvenging property by DPPH free radical. The anti-inflammatory activity was investigate with 5 and 10 pg/ml LPS treated HGFS at MIC, 2 and 4 times of MIC of fraction A and C extracts. PGE, levels were determined by ELISA. HGFs toxicity was investigated by MTT colorimetric assay. Result: Semi-purified A. occidentale fractions A and C presented the widest clear zones and their MIC were 1.25 and 2.5 mg/ml, respectively. The free radical scavenging activity (ECs, value) of fraction C was significant stronger than ascorbic acid (control) and fraction A at 1.33 ± 0.03, 2.17 ± 0.04, and 17.33 ± 0.51 μg/ml, respectively. MIC, 2 and 4 times of both fraction presented PGE, levels lower than control groups significantly at p < 0.05 and the survival rate of HGFs with the extract was not significantly different with the control. Conclusion: The fraction A and C semi-purified A. occidentale leaf extract had antimicrobial antioxidant and anti-inflammatory activities. The fraction A extract was shown non-toxicity to HGFs, so it can be used this fraction as the alternative medicine to treat infectious-inflammatory oral diseases.