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BACKGROUND: Haematoxylum brasiletto is a tree that grows in Central America, commonly known as "Palo de Brasil," which is used in the traditional medicine for the treatment of cancer and gastric ulcers. OBJECTIVE: The aim of this study was to isolate the compounds responsible for antiproliferative activity of H. brasiletto. MATERIALS AND METHODS: A bioassay-guided fractionation of ethanol extract of H. brasiletto was performed using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide cell proliferation assay to measure the antiproliferative activity on six human cancer cell lines (A549, LS180, HeLa, SiHa, MDA-MB-231, and NCI-H1299) and one human noncancer cell line (ARPE-19). The ethanol extract was partitioned with hexane, dichloromethane, and ethyl acetate. The active dichloromethane fraction was fractioned by silica-column chromatography, and active subfractions were separated using preparative-thin layer chromatography. The chemical structure of an isolated compound was elucidated with different chemical and spectroscopic methods. RESULTS: The flavonoid brazilin (1) was isolated from the heartwood of H. brasiletto. The measurement of antiproliferative activity showed that brazilin can inhibit the growth of SiHa, MDA-MB-231, A549, and NCI-H1299 cell lines by 50% at doses of 44.3, 48.7, 45.4, and 48.7 µM, respectively. Furthermore, the flavonoid showed a high antiproliferative activity on LS 180 and HeLa with IC50 values of 62.2 and 71.9 µM, respectively. Brazilin also exhibited a high antiproliferative activity on the human noncancer cell line ARPE-19 with an IC50 value of 37.9 µM. CONCLUSIONS: Brazilin: (6aS, 11bR)-7,11b-Dihidro-6H-indeno[2,1-c] cromeno-3,6a, 9,10-tetrol was isolated; this compound demonstrated antiproliferative activity against several human cancer cell lines. This work demonstrated that brazilin, a flavonoid isolated and characterized of H. brasiletto, has antiproliferative activity against cancer cell lines. SUMMARY: The flavonoid brazilin was isolated from the heartwood of H. brasilettoBrazilin is able to inhibit the growth of SiHa, MDA-MB-231, A549 and NCI- H1299 cancerous cell linesBrazilin exhibited a moderate antiproliferative activity on the human non-cancer cell line ARPE-19Brazilin demonstrated to have antiproliferative activity against human cancer cell lines and could be a potential source of anticancer agents. Abbreviations used: MTT: [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium]; FBS: Fetal bovine serum; TLC: Thin layer chromatography.

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BACKGROUND: Ethnopharmacological relevance. Jatropha neopauciflora (Pax) is an endemic species of the Tehuacan- Cuicatlan Valley, Mexico. This species has long been used as a remedy to alleviate illnesses of bacterial, fungal and viral origin. Aim of the study. Experimentally test the traditional use of Jatropha neopauciflora in Mexican traditional medicine. MATERIALS AND METHODS: The methanol extract (MeOH1), of Jatropha neopauciflora (Euphorbiaceae) was obtained by maceration. Next, the methanol (MeOH2) and hexane (H) fractions were obtained. The essential oil was obtained by hydro- distillation. The extract, fractions and essential oil were analyzed by GC-MS. The antimicrobial activity was measured by the disc diffusion agar and radial inhibition growth methods. RESULTS: The extract and fractions showed antibacterial activity against eleven strains (five Gram-positive and six Gram- negative) and a bacteriostatic effect in the survival curves for Staphylococcus aureus and Vibrio cholerae. The extract and fractions were also shown to have antifungal activity, particularly against Trichophyton mentagrophytes (CF50 = MeOH1: 1.07 mg/mL, MeOH2: 1.32 mg/mL and H: 1.08 mg/mL). The antioxidant activity of MeOH1 (68.6 µg/mL) was higher than for MeOH2 (108.1 µg/mL). The main compounds of the essential oil were ß-pinene, 1,3,8-p-menthatriene, ledene, m- menthane, linalyl acetate and 3-carene. The main compounds of MeOH1 were ß-sitosterol, lupeol and pyrogallol; the main compounds of MeOH2 were ß-sitosterol, spathulenol, coniferyl alcohol and lupeol; and the main compounds of H were ß-sitostenone, γ-sitosterol and stigmasterol. CONCLUSIONS: This study indicates that Jatropha neopauciflora is a potential antibacterial and antifungal agent.

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Six known pentacyclic triterpenes possessing oleanane, lupane, or taraxerane-type skeletons were isolated from the leaves of Sebastiania adenophora (Euphorbiaceae) and are reported for the first time in this species. These compounds include 3-epi-beta-amyrin, beta-amyrinone, 3-epi-lupeol, lupenone, taraxerol, and taraxerone. Structures were elucidated by comparison with literature data. The bioactivities of these compounds were tested on the root growth of Amaranthus hypochondriacus, amaranth (Amaranthaceae), Lycopersicon esculentum, tomato (Solanaceae), and Echinochloa crus-galli, barnyard grass (Poaceae). All six triterpenes were selectively bioactive. An important stimulatory effect was observed on amaranth root growth (23% to 56%) for almost all tested triterpenes (250 microg/ml). These triterpenes significantly inhibited the root growth of barnyard grass (28% to 78%) and tomato (23% to 49%). Aqueous leachate and organic extracts of S. adenophora leaves significantly inhibited the root growth of all test species. The possible ecological role of the allelochemicals isolated is discussed.

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The hexane extract and two sesquiterpenic compounds, cacalol and cacalone, were isolated from the roots and rhizomes of Psacalium decompositum. Then, their anti-inflammatory activity was evaluated in carrageenan-induced rat paw edema and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear edema. Indomethacin was used as the anti-inflammatory agent of reference. In the rat paw model of inflammation, both the hexane extract and the sesquiterpenes isolated from Psacalium decompositum showed a clear dose-dependent inhibition of the carrageenan-induced edema (P < 0.05), with important differences among them during the temporal course of the inhibition. In the TPA-induced mouse ear edema all tested compounds showed anti-inflammatory activity in dose-dependent manner (P < 0.05). In both models, cacalone showed the most prominent anti-inflammatory activity. We conclude that some of the beneficial effects attributed to Psacalium decompositum in traditional medicine can be related with the anti-inflammatory activity of cacalol and cacalone.

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The hypoglycemic effect of the hexane, methanol and water extracts obtained from roots of Psacalium decompositum (Asteraceae) was investigated in fasting healthy mice. Only the water extract significantly reduced blood glucose in a dose-dependent manner in normal mice after intraperitoneal administration (P<0.05). This water extract was macerated with methanol obtaining a precipitate (WMP fraction), and it was studied in healthy and alloxan-diabetic mice. The WMP fraction showed significant hypoglycemic activity in healthy and mild diabetic mice, but the administration of this fraction to animals with severe diabetes did not cause any significant decrease in blood glucose levels. Two polysaccharide components isolated from WMP fraction showed hypoglycemic effect when tested in healthy mice.

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The hypoglycemic activity of Psacalium decompositum (Asteraceae) was investigated in fasting healthy mice and alloxan-diabetic mice. The freeze-dried water decoction significantly reduced the blood glucose in normal mice (from 50.9 +/- 4.7 to 32.5 +/- 3.1 mg/dl) and in mild diabetic mice (from 208.5 +/- 13.0 to 52.3 +/- 7.0 mg/dl), 240 min after intraperitoneal administration (P < 0.005). This preparation also diminished fasting glycemia in severe diabetic mice, but the effects were minor (from 394.4 +/- 9.4 to 289.3 +/- 39.5 mg/dl). The main sesquiterpenoid constituents from P. decompositum roots, cacalol, cacalone and maturin, as well as the transformation product cacalol acetate, did not show a hypoglycemic effect on healthy mice. Nevertheless, two polysaccharide fractions (F1 and F3) obtained from the freeze-dried water extract significantly reduced the fasting glycemia in healthy mice. The best results were obtained with the F1 fraction.

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A germination bioassay employing radish (Raphanus sativus L.) seeds was used for the identification and quantification of the synergistic or antagonistic effects of equimolar binary mixtures formed by the combination of (S)-naproxen, (S)-ibuprofen, (S)-naproxol and (S)-ibuprofen alcohol, by using an approach based on experiments with mixtures. Synergistic effects were found to be statistically significant for the radicle growth of the binary mixtures formed by the combination of (S)-naproxol with (S)-naproxen, and (S)-naproxol with (S)-ibuprofen alcohol. These findings might indicate the existence of the corresponding potential drug-drug interactions. However, due to the complexity of the biological processes in humans and the fact that the correlation between this bioassay and human biological activity has not yet been established, further studies with other organisms or test systems are necessary to confirm the existence of these drug-drug interactions.

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A germination bioassay with radish (Raphanus sativus L.) seeds was developed as a toxicological screening system for assessing the effects of new potential prodrugs of naproxen, as an alternative to animals and animal cell toxicity screens. Both enantiomers of naproxen (6-methoxy-α-methyl-2-naphthaleneacetic acid) and naproxol (6-methoxy-ß-2-naphthaleneethanol), and their racemic mixtures, inhibited the radicle growth of R. sativus at a concentration of 1mM, while only (R)-(+ )-naproxol and racemic naproxol inhibited the hypocotyl growth of R. sativus at the same concentration. Four novel combinatorial esters, naproxen naproxyl esters (6-methoxy-ß-methyl-2-naphthaleneethyl 6-methoxy-α-methyl-2-naphthaleneacetate), resulting from the combinatorial chemistry of the esterification reaction between naproxen and naproxol, were synthesised and then tested in the germination bioassay, at a concentration of 0.5mM. It was found that they did not inhibit either the radicle or the hypocotyl growth of R. sativus.

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The effects of Psacalium decompositum, Psacalium peltatum and Acourtia thurberi (Asteraceae) on blood glucose levels were investigated in fasting mice and temporally hyperglycemic rabbits. The root decoction of P. decompositum reduced the blood glucose of normal mice from 49.1 +/- 3.8 to 35.7 +/- 2.0 mg/dl after intraperitoneal administration (P < or = 0.005) and significantly lowered the hyperglycemic peak (17.1%) in rabbits with temporal hyperglycemia. P. peltatum and A. thurberi decoctions also diminished fasting glycemia in mice and hyperglycemia in rabbits, but the effects were minor. A preliminary phytochemical study using thin layer chromatography showed that water decoctions of the three roots contained alkaloids and sugars. P. decompositum and P. peltatum showed the presence of maturine. However, other furoeremophylanes, such as cacalol and cacalone were only present in P. decompositum. A. thurberi root water decoction showed the presence of the benzoquinone perezone, and its derivative pipitzol.

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The effect of an allelopathic compound, diacetyl-piquerol on the H(+) -ATPase activity of the microsomal fraction from the radicles of a common weedIpomoea purpurea was studied. The diacetyl-piquerol inhibited the germination and radicle growth fromI. purpurea; the radicle growth was increasingly inhibited (10% to 100%) as piquerol concentrations were raised (10 µM to 1000 µM). The H(+)-ATPase activity was inhibited (48%) by 500 µM diacetyl-piquerol, and this inhibition was higher in plasma membrane ATPase (67.2%) than in tonoplast membrane ATPase (31.4%). Additional studies of the precise physiological mechanisms of interference caused by allelopathic compounds are needed.