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UPV Theses and Dissertations

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    Antidiarrheal activity of Pterocarpus indicus bark extracts using castor oil-induced diarrhea model on mice
    Cabatea, Norberto C. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2010-04)
    This study evaluated the antidiarrheal activity of the bark of Pterocarpus indicus (Narra). The crude methanolic extract of the bark was subjected to sequential extraction using hexane, DCM, and ethyl acetate. These extracts were tested for antidiarrheal activity in vitro using the castor oil induced diarrhea model in mice employing charcoal tracing method. Thin Layer Chromatography (TLC) was used in determining the chemical constituents present in every extracts using spraying reagents to aid in the visualization of spots. Crude methanolic extract dosage 200 mg/kg body weight is the comparable dosage to the reference drug loperamide (2 mg/kg body weight). The hexane extract was the most active fraction and 200 mg/kg dosage was more effective than with the positive control loperamide (2 mg/kg). No antidiarrheal activity found in the fraction of DCM and ethyl acetate extracts. Phytochemical screening revealed positive tests for tannins, phenolics, terpenes, cardiac glycosides, saponins and reducing sugars in all fractions. Tests for flavonoids and alkaloids, however, were negative.
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    In vitro antibacterial activity of Hibiscus rosa sinensis leaf extracts against some pathogens associated with urinary tract infections
    Cabayao, Coney B. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2011-04)
    The in vitro antibacterial activity of Hibiscus rosa sinensis leaf ( methanolic, dichloromethane, ethyl acetate, n-hexane, and aqueous ) extracts were studied against Gram-negative (Escherichia coli and Pseudomonas aeruginosa ) and Gram-positive ( Streptococcus faecalis) bacteria. The methanolic extract was subjected to sequential liquid-liquid extraction using solvents of varying polarity and concentrations. Out of the 5 extracts, methanolic and dichloromethane extracts exhibited the highest antibacterial activity as measured using the zone of inhibition. This was followed by ethyl acetate and n-hexane extracts. At 200 mg/ml concentration, all extracts were considered active when tested with E. coli and S. faecalis, and were partially active against P. aeruginosa. The aqueous extract was inactive towards the three bacteria. The 200 mg/ml concentration showed no significant difference when compared with the positive control, amoxicillin (12.51μg/ml). This shows that Hibiscus rosa sinensis exhibits a promising antibacterial activity. Phytochemical analysis of the active fraction- the methanolic extract- showed the presence of alkaloids, tannins, glycosides, saponins, steroids, flavonoids, terpenoids, and anthraquinones. These bioactive components could be responsible for the antibacterial activity of Hibiscus rosa sinensis leaf extracts.
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    The pharmacological screening of Moringa oleifera Lam.
    Burgos, Karen J. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1998-07)
    Moringa oleifera, Lam, or malunggay, belongs to Family Moringaceae. The medicinal value of this plant has long been recognized in folk medicine. Not all the claims, however, are proven scientifically. This study aimed to (1) test the crude extracts from the seeds and leaves of M. oleifera for pharmacological properties and (2) to compare its efficacy with the drugs commonly used to alleviate particular ailment. Phytochemical assay for alkaloid using Culvenor-Fitzgerald method was done to test the presence of alkaloids. The dried seeds and young leaves were extracted with methanol and concentrated under reduced pressure at 45°C. The resulting extracts were partitioned and used for the different assays: Brine shrimp assay for cytotoxicity, Acetic acid-induced writhing assay for analgesic activity, Charcoal tracing assay for antispasmodic activity and paper disc diffusion method for antimicrobial activity. Result showed that only the seeds have alkaloids. Toxicity test revealed that the seeds are practically non-toxic but the leaves were toxic with an LC50 of 550 μg/mL after 24 hours of exposure. Of the two extracts, only the leaves exhibited analgesic activity although not as effective as Mefenamic Acid in reducing pain. The leaf extract, was also found active against Bacillus subtilis, Staphylococcus aureus , Escherichia coli,and Pseudomonas aeruginosa. The seed extract was active only against B. subtilis. Both extracts, however, are not as effective as the antibiotic drug, Amoxicillin. Results also showed that both extracts do not have antispasmodic activity. The study confirmed the antimicrobial and analgesic activities for the use of the leaves of this plant in folk medicine.