Effect of Extreme Temperature Storage on Flavonoids levels and Antibacterial activity of Lantana camara Linn. leaf extract cream

Abstract

L. camara Linn. leaf extract cream has been proven to be effective as an anti-bacterial, specifically against Escherichia coli and Staphylococcus aureus. A long time storage at extreme temperature can affect its flavonoid content and antibacterial activity. Therefore, this study aims to determine the change of quercetin equivalent flavonoid levels in the L. camara Linn. leaf extract cream stored at an extreme temperature of 45 o C, and 75% relative humidity for 1 month, as well as its antibacterial activity against E. coli and S. aureus. The results showed that quercetin equivalent flavonoid levels of L. camara Linn. leaf extract cream at 3%, 4%, and 5% on day 0 are 41.76±1.03mg/100gr, 82.02±1.07mg/100gr, and 31.07±0.85mg/100gr, respectively. After storage on day 30, they were 42.43±1.14mg/100 gr, 80.51±1.24mg/100gr, and 34.34± 0.75mg/100 gr, respectively. Inhibition zone diameters of 3%, 4%, and 5% L. camara Linn. leaf extract against E. coli on day 0 were 11.52±0.71mm, 13.60±0.51mm, and 13.28±0.68mm, while after storage on day 30, they were 8.58±0.61mm, 8.58±0.62mm, and 9.08±0.23mm. Furthermore, for S. aureus on day 0, values of 16.32±0.47 mm, 13.50±0.63 mm, 13.50±0.61mm were obtained, while they were 8.52±0.76mm, 9.3±0.58mm, and 9.5±0.60mm after storage. This indicated that the quercetin equivalent flavonoid of L. camara Linn. leaf extract cream at 3%, 4% are stable after storage at 45oC and 75% relative humidity for 1 month, while it is unstable at 5%. The storage conditions for the three concentrations of L. camara Linn. leaf extract reduced the antibacterial activity against E. coli and S. aureus.