Potential of Leucas zeylanica extract to eliminate E. coli and S. aureus in Corbicula fluminea (“Etak”) tissue


  • Faizuan Abdullah Universiti Malaysia Kelantan, Faculty of Earth Science, Department of Natural Resources and Sustainability.
  • Siti Nor Aini Md. Nasir
  • Dee Koh Han
  • Suganthi Appalasamy
  • Maryana Mohamad Nor
  • Aweng Eh Rak




Corbicula fluminea, etak, Leucas zeylanica, antibacterial, E. coli, S. aureus


“Etak” or Corbicula fluminea, is a freshwater mollusc species regularly consumed as a popular snack among the Kelantanese in Malaysia. The “etak” is usually heated with traditional smoking process which is considered as half cooked and the smoked C. fluminea is commonly known as “etak salai”. This study focuses on the potential of Leucas zeylanica leaves extract to eliminate the bacteria content in “etak salai”. Extraction of bacterial genomic DNA was performed and confirmed the existence of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in “etak salai”. Antibacterial properties of L. zeylanica leaves extract was identified using disc diffusion assay and the result obtained exhibit that 70 μg/μL of L. zeylanica extract was the optimum concentration to give the effect of 11 mm inhibition zone for E. coli and 15 mm inhibition zone for S. aureus. This finding proof that L. zeylanica leaves could be the ingredients in the paste for “etak salai” preparation.


Shamsul, Z. N. M., A. E. Rak, S. H. Samae, S. A. S. Omar, L. A. Afip, Preliminary assessment of Corbicula fluminea in Saiburi river, Southern Thailand. Borneo Journal of Resource Science and Technology, 2017. 7(2): p. 76-83.

Kharel, K., V. K. Yemmireddy, C. J. Graham, W. Prinyawiwatkul, A. Adhikari, Hot water treatment as a kill-step to inactivate Escherichia coli O157:H7, Salmonella enterica, Listeria monocytogenes and Enterococcus faecium on in-shell pecans. LWT, 2018. 97: p. 555-560.

Das, S. N., V. J. Patro, S. C. Dinda, A review: Ethnobotanical survey of genus Leucas. Pharmacognosy Reviews, 2012. 6(12): p. 100-106.

Saritha, K., A. Rajesh, K. Manjulatha, O. H. Setty, S. Yenugu, Mechanism of antibacterial action of the alcoholic extracts of Hemidesmus indicus (L.) R. Br. ex Schult, Leucas aspera (Wild.), Plumbago zeylanica L., and Tridax procumbens (L.) R. Br. ex Schult. Frontiers in Microbiology, 2015. 6(577): p. 1-9.

Zhang, X., M. Gui, C. Zhang, C. Chen , L. Yu, J. Liu, Leucasinoside: A new abietane diterpenoid glycoside from Leucas zeylanica. Records of Natural Products, 2016. 10(5): p. 645-648.

Napagoda, M. T., B. M. A. S. Malkanthi, S. A. K. Abyawardana, M. M. Qader, L. Jayasinghe, Photoprotective potential in some medicinal plants used to treat skin diseases in Sri Lanka. BMC Complementary and Alternative Medicina, 2016. 16(1): p. 479.

Tanase, A.-M., L. Mereuta, L. Chiciudean, R. Lonescu, L. Milea, C. P. Cornea, T. Vassu, I. Stoica, Comparison of total DNA extraction methods for microbial community form polluted soil. Agriculture and Agricultural Science Procedia, 2015. 6: p. 616-622.

Babu, A., M. S. N. Mohamed, K. Jaikumar, D. Anand, P. Sarvanan, In-vitro antifungal activity of leaf extracts Of Leucas aspera And Leucas zeylanica. International Journal of Pharmaceutical Sciences and Research, 2016. 7(2): p. 752-756.

Gebreyohannes, E.A., et al., PRM204 - Recreational Use of Phosphodiesterase 5 Inhibitors and Its

Associated Factors Among Undergraduate Male Students In An Ethiopian University: A Cross-Sectional Study. Value in Health, 2016. 19(7): p. A394.

Biswas, B., K. Rogers, F. McLaughin, D. Daniels, A. Yadav, Antimicrobial activities of leaf extracts of guava (Psidium guajava L.) on two gram-negative and gram-positive bacteria. International Journal of Microbiology, 2013. 2013: p. 1-7.

Stefanello, M. É. A., A. C. Cervi, I. Y. Ito, M. J. Salvador, A. W. Jr, E. L. Simionatto, Chemical composition and antimicrobial activity of essential oils of Eugenia chlorophylla (Myrtaceae). Journal of Essential Oil Research, 2008. 20(1): p. 75-78.

Singh, M. K., A. Pandey, H. Sawarkar, A. Gupta, B. Gidwani, H. Dhongade, D. K. Tripathi, Methanolic extract of Plumbago zeylanica - A remarkable antibacterial agent against many human and agricultural pathogens. Journal of Pharmacopuncture, 2017. 20(1): p. 18-22.

Chew, A. L., J. J. A. Jessica, S. Sasidharan, Antioxidant and antibacterial activity of different parts of Leucas aspera. Asian Pacific Journal of Tropical Biomedicine, 2012. 2(3): p. 176-180.

Malanovic, N., K. Lohner, Antimicrobial peptides targeting gram-positive bacteria. Pharmaceuticals, 2016. 9(3): p. 59.

Srinivasan, D., S. Nathan, T. Suresh, P. L. Perumalsamy, Antimicrobial activity of certain Indian medicinal plants used in folkloric medicine. Journal of Ethnopharmacology, 2001. 74(3): p. 217-20.