-Context -Ulcer is the most common gastrointestinal disturbance resulting from an inadequate gastric mucosal defense.Several drugs are available in the market to address the disease; however, these drugs are associated with unnecessary side effects. Objectives -Previous research have confirmed the efficacy of plant extracts for possible treatment of the disease. This research aims to evaluate the anti-ulcer properties of medicinal plants. Methods -Methanol extracts from the leaves of Intsia bijuga, Cynometra ramiflora, Tamarindus indica, Cassia javanica, Cassia fistula, Bauhini purpurea, Senna spectabilis, Senna siamea and Saraca thaipingensis were evaluated for their anti-ulcer activity using HCl-ethanol as ulcerogen. Results -All extracts showed inhibitory activity with I. bijuga, T. indica, S. spectabilis and S. thaipingensis exhibiting more than 50% inhibition. S. thaipingensis showed the highest activity at 80%. S. spectabilis and S. thaipingensis were partitioned further into hexane, ethyl acetate and aqueous fractions. The aqueous and ethyl acetate fractions of S. spectabilis showed significant increased in its activity while the hexane and ethyl acetate fractions of S. thaipingensis gave higher activity than its aqueous portions. Conclusion -We conclude that plant extracts are potential sources of new anti-ulcer agents.

T. fluminensis is a potentially good source of 15-lipoxygenase inhibitors.

The genotoxicity and toxicity of ethnomedicinal Philippine plants, which include Cassia fistula, Derris elliptica, Ficus elastica, Gliciridia sepium, Michelia alba, Morus alba, Pogostemon cablin and Ricinus communis, were tested using the Vitotox assay. The plants are used traditionally to treat several disorders like diabetes, weakness, menorrhagia, headache, toothache and rheumatism. The dried leaves were homogenized for overnight soaking in methanol at room temperature. The resulting alcoholic extracts were filtered and concentrated in vacuo and tested for their genotoxicity and cytotoxicity using Vitotox®. Results showed that the medicinal plants that were tested are not genotoxic nor cytotoxic, except for R. communis and P. cablin, which showed toxicity at high doses (low dilutions) in the absence of S9.

Solvent fractions and decoction of Eleusine indica leaves were tested for their ability to inhibit angiotensin-converting enzyme (ACE), an important component of the Renin-AngiotensinAldosterone System which is a critical regulator of arterial blood pressure. The ACE inhibitory activity of each fraction was measured by employing a colorimetric assay based on the hydrolysis of histidyl-hippuryl-leucine (HHL) by ACE. Preliminary assay results revealed that the ethyl acetate fraction exhibited the highest antihypertensive activity with a percent inhibition of 51.51%. This fraction was considered for further isolation using a bioassay-guided fractionation scheme. Regulation of blood pressure by RAAS is via angiotensin release and body electrolyte content via aldosterone release. 6 One component of the RAAS is the hydrolase, AngiotensinConverting Enzyme (ACE), is responsible for converting angiotensin I to angiotensin II, a known potent vasoconstrictor. Angiotensin II stimulates both the synthesis and release of aldosterone from the adrenal cortex resulting to an increase in blood pressure via sodium retention.7 Thus, the concept of inhibiting ACE became a popular and effective therapeutic approach in treating hypertension and other cardiovascular diseases. The first oral ACE inhibitor, captopril, l was considered a breakthrough in managing blood pressure and was also an early example of a structure-based drug design. 4 Other synthetic ACE inhibitors which are widely used for clinical use in the treatment of hypertension include enalapril, alcacepril, and lisinopril.8 Just like the early antihypertensive drugs, synthetic ACE inhibitors are also associated with a few side effects such as dry cough and angioedema. The current trend in anti-hypertensive drug research is finding potential ACE inhibitors from natural products that mimic synthetic ACE inhibitors and provide health benefits without adverse effects. There have been several bioactive compounds extracted from plants which were found to possess in vitro ACE inhibitory activity such as flavonoids, hydrolasable tannins, phenylpropanes, xanthones, fatty acids, terpenoids, alkaloids, proanthocyanidins, oligosaccharides, and peptide amino acids. chloride (BSC) to develop the yellow color. Then the absorbance was measured at 410 nm using a microplate reader. The following formula was used to determine percent inhibition: Vacuum liquid chromatographyThe crude fraction with the highest percent inhibition was subjected to vacuum liquid chromatography (VLC). A short column was dry-packed with 70.0 g of silica using suction and manual pressing to make a sorbent bed (bed volume of 150 mL) onto which the sample, preadsorbed in silica, was added. Then the column was pre-treated with 300-mL hexane under light suction. Thereafter, the column was successively eluted with a series of solvents consisting of hexane, hexane combined with increasing amounts of ethyl acetate in 10% increment, ethyl acetate, ethyl acetate combined with methanol (1:1), and methanol. Methanol w...

Several extracts from Philippine medicinal plants used for asthma and other inflammatory diseases were evaluated for their ability to inhibit the action of 15-lipoxygenase. The inhibitory activity was tested spectrophotometrically using quercetin as positive control. Eleven species belonging to 11 families displayed varying inhibitory activities. Commelina diffusa and Euphorbia hirta showed the highest inhibitory activity at 51.3% and 48.5%, respectively. These plants may contain new 15-lipoxygenase inhibitors.