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ABSTRACT ESPIRITU, RHEA R. Mariano Marcos State University. May 2021. REEP DIVERSITY AND BIOCHEMICAL EVALUATION OF NEMATOCYSTS DERIVED FROM Millepora tenera (Nemenzo, 1975) Milleporidae IN BADOC, ILOCOS NORTE Major Adviser: Andres Y. Tungpalan, MSc Marine resources such as seaweeds and seagrasses have been utilized as pharmaceutical sources, while invertebrate’s species, specifically the slow-moving organisms, are the only representatives of the faunal group used for this purpose. In this regard, the present study was done to highlight the capacity of corals as a possible source of secondary metabolites, which may be a potential source of ingredients to combat the growth and survival of pathogens. Moreover, the study aims to evaluate the synergistic effect on Artemia salina nuplii. Identification of coral species present in the site was made to assess dominant and thriving species using updated methods formulated by various authors. A total of 34 species of corals were observed thriving around the island. Generally, the area is dominated by submassive, massive, and encrusting corals species. They were found at deeper depths where the environment is at its best for them to survive, such as temperature and light. In contrast, branching species were found to compete with seaweeds and other associated flora and fauna at a shallower depth. Evaluation of how healthy they are was done by documenting natural and human triggered disturbances affecting their growth. Observed disturbances around the island were categorized into four: diseases (tissue necrosis and pink line syndrome), human and weather exposure, invasive species/predation such as Drupella spp., and species of seaweeds, which seemed to affect the growth of coral species around the island. Characterization of nematocyst of Millepora tenera was done. The microscopic activity revealed that macrobasic b-mastigophores were found abundantly in the extract. Undischarged nematocysts that look like an egg-shaped capsule and discharged nematocysts with everted tubule were observed. Evaluation of secondary metabolites proved flavonoids, phenolic compounds, tannins, and alkaloids in the extracted nematocyst of M. tenera. Color reaction, precipitate formation, and other remarkable changes or observations on the extracted nematocysts were the basis for the presence or absence of the bioactive compounds. Extracted nematocysts were used to evaluate the biological activity against pathogens, namely: Staphyloccus aureus, Candida albicans, and Escherichia coli. In the case of E. coli, prepared concentrations surpassed the ability of the positive control, Clindamycin, in inhibiting their growth. Results show that E. coli has high sensitivity and specificity at 75% to 100% M. tenera extract, respectively. For S. aureus and C. albicans, prepared concentrations failed to surpass the efficacy of the positive control, but a mild effect on inhibition and thinning of bacterial growth was observed. Microbial activity is attributed to the synergistic effect of observed secondary metabolites in the extracts. Toxicity assay was done using Artemia salina nuplii against the prepared concentration. The assay was divided into two: the range finder and the specificity test. Specificity test shows that extract of M. tenera is highly toxic at 0.05% to 0.1%. decreases. Observation shows positive relation such that as concentration decreases, toxicity level With the prevailing scenario that different pathogens become the cause of various diseases, various studies done by researchers searching for alternate source cures to these diseases are given utmost importance. |
