Inhibition of Gingipain K from Porphyromonas Gingivalis by Cratoxylum Cochinchinense Extract

Lee, Su Ying (2022) Inhibition of Gingipain K from Porphyromonas Gingivalis by Cratoxylum Cochinchinense Extract. Final Year Project (Bachelor), Tunku Abdul Rahman University College.

Text LEE SU YING_Full Text.pdf Restricted to Registered users only Download (1MB)

Abstract

Porphyromonas gingivalis is a pathogenic bacterium that plays a significant role in the progression of periodontal disease. It is involved in inflammation and in tissue destruction during periodontal disease and it is found to be linked with several diseases, including Alzheimer’s disease, cardiovascular disease, diabetes mellitus and rheumatoid arthritis. Lys-gingipain (Kgp), the trypsin-like cysteine proteinase, is one of the major virulence factors for this bacterium. Gingipain K has been reported to be associated with systemic diseases such as aspiration pneumonia, Alzheimer’s disease, diabetes mellitus, preterm birth and low birth weight. In this study, we aim to investigate the inhibitory effects of Cratoxylum cochinchinense methanolic leaves extract against Kgp of P. gingivalis. The cultivation of P. gingivalis bacteria was carried out by streaking the previously cultured bacteria onto TSA plates using aseptic technique. The plates were then kept in an anaerobic jar and incubated at 37°C for 7 days. After 7 days of culture, P. gingivalis bacteria were suspended in the gingipain assay buffer to an OD660 of 0.03. The extract was diluted into desired concentrations for the Kgp inhibition assay. The positive control used for the inhibition assay was Nα-tosyl-L-lysine chloromethyl ketone hydrochloride (TLCK). The results showed that methanolic leaves extract of C. cochinchinense revealed inhibition properties towards Kgp in a dose-dependent manner when tested at concentrations 0.0625 mg/ml, 0.0125 mg/ml and 0.25 mg/ml. Besides, mangiferin reported present in C. cochinchinense demonstrated inhibitory effects on gingipain K activity when tested at the concentrations 1 μM, 10 μM and 100 μM. In conclusion, the methanolic leaves extract of C. cochinchinense and mangiferin are potential inhibitors of Kgp and could be used as a treatment for P. gingivalis linked diseases such as Alzheimer’s disease