Applied Sciences > Medicine > D-132

Research Title Xanthine Oxidase Inhibitors from Selected Philippine Plants
Research Personnel Leader:
Dr. Christine C. Hernandez
Ms. Karmella Apaya
Research Duration Start:
1 November 2010
1 November 2012
Research Location Institute of Chemistry, UP Diliman
Research Description Although allopurinol is a very eficient drug, there is a relatively high incidence of adverse effects seen with allopurinol in patients with gout, hence the need for new and improved xanthine oxidase inhibitors. The isolated and purified compounds could be used as a marker for standadization of herbalproducts sothey can be available as phytomendicines. The interest in herbal products as a re-emerging health aid is fueled by the rising cost of drugs.
Research Objectives The study aims to (1) isolate anti-gout compounds from terrestrial plants, and (2) elucidate the structure of anti-gout compounds from terestrial plants. Specifically, it aims to (1) screen terrestrial plant extracts for their xanthine oxidase inhibitory action, (2) identify the plant with the highest xanthine oxidase inhibitory activity, (3) isolate and purify the bioactive constituents using bioassay directed scheme, (4) determine the structure of the anti-gout constituents using spectral analysis, and (5) confirm the xanthine oxidase inhibitory action of the purified compounds.
Research Beneficiary(ies) People suffering from the disease and pharmaceutical companies
Research Accoplishments Xanthine oxidase catalyzes the formation of uric acid from hypoxanthine and xanthine. Elevated levels of uric acid in the blood and urine cause the metabolic disease gout, a disease characterized by urate crystal deposition in the joints, causing extreme inflammation and pain. Moreover, this condition leads to co-morbidities like hypertension, and diabetes. Inhibition of xanthine oxidase is therefore crucial in the prevention of gout and related diseases. In this research, extracts from Philippine plants traditionally used for inflammation were studied for their xanthine oxidase inhibitory activities. The following plants were used: Adenanthena payonina, Antegonon leptopus, Blumea balsamifera, Calophyllum inophyllum, Cassia alata, Cassia fistula, Gliricidia sepium, Michelia alba, Mimosa pudica, Portulaca olercea, Pogostemon cablin, Solanum tornum, Tinosphora rumphii and Vitex negundo. The leaves were extracted with methanol and partitioned with ethyl acetate and hexane. Extracts were then subjected to bioactivity assay. Plants which yielded the highest activity were found to have 87% and 63% inhibition for the aqueous extract of A. leptopus and the ethyl acetate extracts of M. pudica, respectively. Bioassay guided fractionation was performed by eluting the active fraction and separating components by weight using 100% methanol in Sephadex LH-20. For A. leptopus, fraction 4 had the highest percent inhibition at 87%; while fraction 7 of M. pudica showed 72% inhibition. Phytochemical screening was performed and showed the presence of flavonoids, cardiac glycosides, phenolic compounds and alkaloids for A.leptopus while the M. pudica extracts were found to have tannins, saponins, terpenoids, flavonoids, phenolic compounds, and steroids. The IC50 values were also determined to be 10.55 ug/mL and 12.23 ug/mL. Active compounds will be purified using reversed-phase HPLC. Spectral analyses using FTIR, mass spectrum, proton and carbon NMR will determine the identity of compounds responsible for xanthine oxidase inhibitory activity.
Total Research Cost ₱946,979.55
Research Agencies Funding:
Institute of chemistry, UP Diliman

Research Budget Breakdown Year:
Year Funded:
Total Cost
Date Released
Amount Released

2009 to 2011


Code D-132
KRA Code Rapid, inclusive, and sustained economic growth
Priority Thrust DOST
Develop Appropriate Tchnologies to Create Growth in the Countryside
Poverty Reduction and Empowerment of the Poor
Sector Applied Sciences
Actual Sector Medical Sciences
Related sectors Natural Products,Pharmaceutical Industry, Chemistry
Entry revision: January 2021