Thesis ( Master of Science in Biology)

Bibliography: leaves 60-70

ABSTRACT PASCUAL, PILAR CAROLYN V. Mariano Marcos State University. May 2019. PHYTOCHEMICAL SCREENING AND BIOACTIVITY OF Carpopeltis flabellara. Halymeniaceae (Okamura, 1935) COLLECTED IN ILOCOS NORTE, PHILIPPINES. Major Adviser: Andres Y. Tungpalan, MS Biology Seaweeds have been consumed by coastal communities especially in Asian countries for their ethnobotanical use. Many marine algae were proven to have different secondary metabolites which makes them a natural source of bioactive compounds used in nutraceutical and pharmacological industries. However, there are only a few culturable seaweeds, thus, this study used the underutilized, non-food red algae Carpopeltis flabellata in Ilocos Norte. The C. flabellata extract was investigated for its phytochemical constituents and biological activity both in-vitro and in-vivo. Initial phytochemical analysis of C. flabellata reveals that extract derived contains bioactive compounds such as alkaloids, saponins, tannins, phenolics, steroids, sterols and terpenoids. The toxic activity of the ethanolic extract was tested against Artemia salina nauplii. Different concentrations of the C. flabellata extract was used in the lethal test for brine shrimp. Mortality rate of the brine shrimp increases as the extract concentration increases. The median lethal dose (LDso) of the extract was at 1.5% concentration. In-vitro antioxidant activity of the ethanolic extract is determined by evaluating the total phenolic content (TPC), DPPH assay and total antioxidant (TAC). C. flabellata extract showed high radical scavenging activity which makes it a potential natural source of antioxidants. This is supported by its high TPC (05.03 pg gallic acid/mg dry sample) and TAC (22.73 ug/ml). In-vivo antioxidant and hepatoprotective potential of the C. flabellata extract was also evaluated. The ethanolic extract was tested against acetaminophen-induced mice and was compared to silymarin treated mice as positive control. The lipid profile (cholesterol and triglyceride) and serum transaminase (AST and ALT) was measured in mice serum. Results revealed that the extract exhibit significant reduction in the cholesterol and triglycerides levels in the mice serum. Likewise, the extract also showed significant effect in lowering AST and ALT levels. The hepatoprotective activity of the extract also showed remarkable results as there are only mild histological changes in the acetaminophen-induced mice treated with C. flabellata ethanolic extract. The results obtained indicate that Carpopeltis flabellata contains phtochemical compounds which possessed toxic, antioxidant, anticholesterimic and hepatoprotective properties.