Sains Malaysiana 51(5)(2022): 1363-1372 http://doi.org/10.17576/jsm-2022-5105-08 Epidermal Mucus of Anabas testudineus as a Promising Source of Antibacterial and Anticancer Agents (Mukus Epidermis Anabas testudineus sebagai Punca Agen Antibakteria dan Antikanser yang Menggalakkan) AHMED ABDULKAREEM NAJM 1 , HERRYAWAN RYADI EZIWAR DYARI 3 , BABUL AIRIANAH OTHMAN 2,4 , SHARIFAH SAKINAH SYED ALWI 5 , AHMAD AZFARALARRIFF 2 , MUHAMMAD SHAHID 1 , SITI AISYAH SANUSI 2 , DOUGLAS LAW 2,6 & SHAZRUL FAZRY 2,4,7,* 1 Department of Biological Sciences and Biotechnology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia 2 Department of Food Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia 3 Department of Earth Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia 4 Innovative Center for Confectionery Technology (MANIS), Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia 5 Department of Biomedical Science, Faculty of Medicine & Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan, Malaysia 6 Faculty of Health and Life Sciences, INTI International University, Persiaran Perdana BBN Putra Nilai, 71800 Nilai, Negeri Sembilan, Malaysia 7 Chini Lake Research Centre, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia Received: 25 November 2020/Accepted: 22 October 2021 ABSTRACT Anabas testudineus is a sturdy freshwater fsh that can live in a polluted environment due to the epidermal mucus (EM) that protects the fsh from pathogens or germs. This study explored the functional properties of the EM as a potential antimicrobial and anticancer agent. Inactive Pseudomonas aeruginosa was introduced into fsh tanks to stimulate the production of EM. This stimulus signifcantly increased EM production by more than 100% after 10 days of stimulation, indicating that EM production was infuenced by environmental biotic stress. In vitro antibacterial activity tests showed that EM has signifcant antibacterial activity against Escherichia coli (12 ± 0.23 mm) and P. aeruginosa (10 ± 0.13 mm) at the tested concentration of 1000 μg/mL. Further characterisation against cells showed that EM has a cytotoxic efect against human breast cancer (MCF7) and human melanoma (A375.S2) producing an IC 50 value of 4.97 ± 0.25 and 6.27 ± 0.17 mg/mL, respectively. In contrast, no cytotoxicity against normal fbroblast skin cells (HS27) was observed. In addition, apoptosis analysis showed that EM could cause DNA fragmentation of cancer cells, while no efect on normal cells was observed. These fndings indicated that EM from A. testudineus could be further studied and explored as an anticancer agent. Keywords: Anabas testudineus; anticancer; antimicrobial peptide; epidermal mucus; mucus secretion ABSTRAK Anabas testudineus adalah ikan air tawar yang lasak dan dapat hidup dalam persekitaran yang tercemar kerana mempunyai mukus epidermis (EM) yang melindungi ikan ini daripada patogen atau kuman. Penyelidikan ini mengkaji tentang sifat berfungsi EM sebagai agen antimikrob dan antikanser yang berpotensi. Pseudomonas aeruginosa yang tidak aktif dimasukkan ke dalam tangki ikan untuk merangsang pengeluaran EM. Rangsangan ini meningkatkan pengeluaran EM dengan ketara lebih daripada 100% selepas 10 hari rangsangan yang menunjukkan bahawa