Undergraduate Theses
Permanent URI for this collectionhttps://hdl.handle.net/20.500.14583/13
Browse
8 results
Filters
Settings
Search Results
Item Antidiarrheal activity of Pterocarpus indicus bark extracts using castor oil-induced diarrhea model on miceCabatea, 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.Item In vitro antibacterial activity of Hibiscus rosa sinensis leaf extracts against some pathogens associated with urinary tract infectionsCabayao, 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.Item 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.Item DPPH free radical scavenging activity and total phenolic content of Talisay (Terminalia catappa) seedsBohol, Lyan Jean B. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2013-04)Free radicals, a class of highly reactive molecules derived from the metabolism of oxygen is believed to be involved in many health disorders. It is generated as by-products of biological reactions or from the environment. Antioxidant-based drugs and formulations for the prevention and treatment of complex diseases have attracted a great deal of research interest in natural antioxidants. It is deemed necessary to screen medicinal plants for their antioxidant potential. Terminalia catappa is a widely-distributed tree in the Philippines with promising potentials in pharmacology. Evaluation of the in vitro antioxidant activity of methanolic, dichloromethane, and hexane extracts of Terminalia catappa seeds were carried out using two assays: 1, l-diphenyl-2-pycrylhydrazyl (DPPH) free radical scavenging assay and total phenolic content assay. Results revealed that methanolic extracts showed a significantly higher free radical scavenging activity and a four-fold increase in its activity relative to the standard Butylated Hydroxytoluene (BHT). Furthermore, methanol, DCM and hexane extracts have high total phenolic content. Present results indicate that Terminalia catappa is a potential source of antioxidant and a good candidate for the development of new nutraceuticals for treatment of diseases. Phytochemical screening to determine the group of secondary metabolites present and toxicity evaluation for recommendation as nutritional substitutes and human consumption are recommended.Item Antimicrobial, antioxidant and phytochemical properties of ethanolic and water extracts of selected local spices from Miagao, IloiloBesinga, Yvonne Grace M. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2016-06)Spices such as garlic, pepper and turmeric are indispensable in the daily food preparation and are reported to have compounds which prevent the microbial spoilage of food. This study evaluates the antimicrobial and antioxidant activities as well as the phytochemical properties of the ethanol and aqueous spice extracts of garlic, pepper and turmeric. The antioxidant activity was performed using l,l-diphenyl-2-picryl- hydrazyl (DPPH) Radical Scavenging Method and the antimicrobial activity was evaluated by Disk Diffusion Assay. Phytochemical compounds tested were alkaloids, flavonoids, terpenoids, phenol and saponins. In decreasing order, the potency of the antioxidant activities showed Ascorbic acid > turmeric ethanol extract >pepper water extract> pepper ethanol extract> turmeric water extract> garlic ethanol extract> garlic water extract. The antimicrobial activity was highest in turmeric aqueous extract in terms of mean inhibition zone (7.5±2.10) against E. coli. The most effective treatment against B. subtilis was turmeric ethanol with highest mean inhibition zone (6.87±1.13). And for S. aureus, garlic ethanol extract has the highest mean inhibition zone (7.80±1.32). Phytochemical screening tests showed that in all treatments, the most abundant phytochemical were alkaloids and terpenoids. This study indicates that the spices like garlic, pepper and turmeric have antimicrobial and antioxidant activity.Item Karyotype analysis of Kutsay Allium odoratum L. (Alliales: Alliaceae)Bermejo, Jo-am Asis (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1995-05)The C-metaphase count of Allium odoratum revealed that the chromosome number was 2n=32, consisting of the following centromeric groups based on Levan's method of chromosome classification: Group I chromosomes with subterminal centromeres (1 pair); Group II with submedian centromeres (2 pairs), and Group III with median centromeres (13 pairs). The mean total lengths of chromosome ranged from 8.534±0.504-16.624±0.600 μ. Mitotic index for the species was found to be 10.87%.Item Karyotype analysis of garlic, Allium sativum L. (Alliales; Alliaceae)Bandiola, Ma. Florma A. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 1994-03)The C-metaphase count of Allium sativum L. showed a chromosome number of 2n = 14, consisting of six long and eight short somatic chromosomes categorized into three distinct groups: ten m type chromosomes with centromeres at the median region, two sm type chromosomes with submedian centromere and two st type chromosomes with subterminal centromere, Mitotic index for the species was computed at 16.88%.Item Development of a high-performance thin layer chromatography (HPTLC)-densitometric method for the estimation of quercetin and kaempferol in Euphorbia hirta (Tawa-tawa) extractBaladjay, Diane Monique S. (Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, 2017-06)A sensitive, fast, efficient, and repeatable high-performance thin-layer chromatographic (HPTLC) method has been developed for simultaneous analysis of quercetin and kaempferol from the extracts of the aerial parts of Euphorbia hirta. In the development of the HPTLC method, different extraction parameters were evaluated and quantification of quercetin and kaempferol in the extract of E.hirta was performed using a densitometric software, Quantiscan™. Among the different combinations of mobile phases used, best separation was achieved in toluene: ethyl acetate: formic acid: methanol (5: 6: 2: 1) solvent system. E.hirta was extracted using the developed extraction method which involves the use of 80% ethanol, 8 minutes of sonication and serial extraction until 3rd extraction. This determined method provides a maximum yield of the compounds at minimum time and cost. The method was also validated for linearity and precision specifically repeatability. The results show that the produced calibration is linear, as supported by the obtained correlation coefficient (r) of > 0.999 and coefficient of determination (R2) of > 0.997. Moreover, the obtained slopes of the calibration curves show that the method is most sensitive towards quercetin and least sensitive to gallic acid. The method was also found out to be repeatable and precise as the %RSD for both the inter-day and intra-day trials obtained a value less than <2%. The present method is being reported for the first time and can be used for routine quality control and quantification of quercetin and kaempferol in various plant samples, extracts, and market formulations.
