Cytotoxicity of sterile culture supernatants of bioluminescent bacteria isolated from Photololigo duvaucelii ink on cancer cells

Date of Publication

8-2017

Document Type

Bachelor's Thesis

Degree Name

Bachelor of Science in Biology

Subject Categories

Biology

College

College of Science

Department/Unit

Biology

Thesis Adviser

Esperanza C. Cabrera

Abstract/Summary

Cancer is considered as one of the top leading causes of death worldwide as proven by statistics. Up until now, the absence of a definite cure, despite the many researchers conducted by scientists, demands the need for further studies on drug development and discovery of effective chemotherapeutic agents. At present, various sources such as plants and organisms are being tapped for anti-cancer compounds. Different studies have shown that compounds extracted from marine organisms have bioactivities such as antibacterial, anti-fungal, anti-cancer, and cytotoxic activities. This study therefore, aimed to evaluate the bioactivities of bioluminescent bacteria isolated from Photololigo duvaucelii (Indian squid) ink as cytotoxic agents against human-derived cancer cell lines. To achieve this, sterile culture supernatants from 17 bioluminescent bacterial isolates were tested for cytotoxicity against 3 human cancer cell lines, namely: small cell lung cancer cell line (H69PR) and colon cancer cell lines (HT-29 and HCT-116); and normal human dermal fibroblasts, neonatal cell line (HDFn), via PrestoBlue resazurin cytotoxicity assay. The cytotoxic activities of the isolates were determined by computing for the cytotoxicity index (CI%) and the IC50 (the concentration that killed 50% of the cells) of the supernatants for the cell lines. Among the 3 cancer cell lines, H69PR and HT-29 were the most susceptible to a number of the supernatant extracts. In particular, a total of 9 isolates were noted to

have IC50 values of < 10 %v/v for each of the two cell lines. On the other hand, for HCT- 116, 5 isolates had IC50 values ranging from 3.18 %v/v to 15.46 %v/v. Moreover, none of

the bacterial culture supernatants were cytotoxic to the normal human fibroblasts (HDFn). Out of the 17 isolates, Isolates 8, 12, and 16 shared a cytotoxic nature for all 3 cancer cell lines. Moreover, 16S rDNA sequencing has shown that 16 of the isolates were identified to be Photobacterium leiognathi. Results thus show that a number of the P. leiognathi isolates tested have potent activities against H69PR, HT-29, and HCT-116, which prove their potential to serve as therapeutic agents for cancer.

Abstract Format

html

Language

English

Format

Electronic

Accession Number

CDTU021791

Shelf Location

Archives, The Learning Commons, 12F, Henry Sy Sr. Hall

Keywords

Squids; Cancer cells; Cell-mediated cytotoxicity

Upload Full Text

wf_no

Embargo Period

5-28-2025

This document is currently not available here.

Share

COinS