The preliminary diuretic test of the chloroform fraction of the leaf of Pandanus tectorius on male Sprague Dawley rats showed a positive diuretic effect with three increasing doses of the semi-purified fraction in comparison to negative control (10% Tween 80 in NSS). The highest diuretic effect was observed at a dose of 500 mg/kg BW, while on diminished effect occurred at the highest dose of 1000 mg/kg BW, suggesting that the chloroform fraction could have a mechanism similar to low-ceiling loop diuretics, where increasing the does beyond a certain amount results to decreased or no corresponding effect.
Two pure compounds labeled Pt-M-Ca-B and Pt-M-Ca-D were isolated from the chloroform fraction of P. tectorius. These were identified as triterpenes based on chemical characterization. Structure elucidation using 1D and 2D-NMR experiments revealed that Pt-M-Ca-B is a C-30 triterpene hydrocarbon with a taraxastane skeleton while Pt-M-Ca-D was identified as the triterpene precursor, squalene.
Due to limited amount of samples, both isolates were not submitted for diuretic assay, a 98 percent pure squalene purchased from Sigma however showed positive diuretic effects in groups of test animals administered with 15 and 60 mg/kg BW. Although the choloform fraction and 98% squalene exhibited positive diuretic effects in terms of increasing urine output of experimental animals, these diuretic effects are not comparable to that of the positive control, Furosemide 930 mg), which is a potent diuretic agent.
As far as extensive literature survey is concerned, this is the first report on the isolation of a taraxastane type triterpene from P. tectorius and the genus Pandanus. Moreover, this is also the first report on the preliminary diuretic assay of squalene. (Author)