Luce Maria Brandão Torres

Diterpene from Baccharis trimera with a relaxant effect on rat vascular smooth muscle

A bioassay monitored fractionation of a chloroform extract from the aerial parts of Baccharis trimera yielded a mixture that blocked the Ca2+-induced contractions of KCl- depolarized rat portal vein preparations. Pharmacological tests of two pure compounds isolated from the mixture revealed the dilactonic clerodane diterpene as the active compound.

Inhibition of gastric acid secretion by a standardized aqueous extract of Cecropia glaziovii Sneth and underlying mechanism

Cecropia glazioui Sneth (Cecropiaceae) is used in folk medicine in tropical and subtropical Latin America as cardiotonic, diuretic, hypotensive, anti-inflammatory and anti-asthmatic. The hypotensive/antihypertensive activity of the plant aqueous extract (AE) and isolated butanolic fraction (BuF) has been confirmed and putatively related to calcium channels blockade in vascular smooth musculature [Lapa, A.J., Lima-Landman, M.T.R., Cysneiros, R.M, Borges, A.C.R., Souccar, C., Barreta, I.P., Lima, T.C.M., 1999. The Brazilian folk medicine program to validate medicinal plants - a topic in new antihypertensive drug research. In: Hostettman, K., Gupta, M.P., Marston, A. (Eds.), Proceedings Volume, IOCD/CYTED Symposium, Panamá City, Panamá, 23-26 February 1997. Chemistry, Biological and Pharmacological Properties of Medicinal Plants from the Americas. Harwood Academic Publishers, Amsterdam, pp. 185-196; Lima-Landman, M.T., Borges, A.C., Cysneiros, R.M., De Lima, T.C., Souccar, C., Lapa, A.J., 2007. Antihypertensive effect of a standardized aqueous extract of Cecropia glaziovii Sneth in rats: an in vivo approach to the hypotensive mechanism. Phytomedicine 14, 314-320]. Bronchodilation and antidepressant-like activities of both AE and BuF have been also shown [Delarcina, S., Lima-Landman, M.T., Souccar, C., Cysneiros, R.M., Tanae, M.M., Lapa, A.J., 2007. Inhibition of histamine-induced bronchospasm in guinea pigs treated with Cecropia glaziovi Sneth and correlation with the in vitro activity in tracheal muscles. Phytomedicine 14, 328-332; Rocha, F.F., Lima-Landman, M.T., Souccar, C., Tanae, M.M., De Lima, T.C., Lapa, A.J., 2007. Antidepressant-like effect of Cecropia glazioui Sneth and its constituents -in vivo and in vitro characterization of the underlying mechanism. Phytomedicine 14, 396-402]. This study reports the antiulcer and antisecretory gastric acid activities of the plant AE, its BuF and isolated compounds with the possible mechanism involved. Both AE and BuF were assayed on gastric acid secretion of pylorus-ligated mice, on acute models of gastric mucosal lesions, and on rabbit gastric H(+), K(+)-ATPase preparations. Intraduodenal injection of AE or BuF (0.5-2.0g/kg, i.d) produced a dose-related decrease of the basal gastric acid secretion in 4-h pylorus-ligated mice. At 1.0g/kg, BuF decreased the volume (28%) and total acidity (33%) of the basal acid secretion, and reversed the histamine (2.5mg/kg, s.c.)- or bethanecol (1.0mg/kg, s.c.)-induced acid secretion to basal values, indicating inhibition of the gastric proton pump. Pretreatment of mice with the BuF (0.05-0.5g/kg, p.o.) protected against gastric mucosal lesions induced by 75% ethanol, indomethacin (30mg/kg, s.c.) or restraint at 4 degrees C. BuF also decreased the gastric H(+), K(+)-ATPase activity in vitro proportionately to the concentration (IC(50)=58.8microg/ml). The compounds isolated from BuF, consisting mainly of cathechins, procyanidins and flavonoids [Tanae, M.M., Lima-Landman, M.T.R., De Lima, T.C.M., Souccar, C., Lapa, A.J., 2007. Chemical standardization of the aqueous extract of Cecropia glaziovii Sneth endowed with antihypertensive, bronchodilator, antacid secretion and antidepressant-like activities. Phytomedicine 14, 309-313], inhibited the in vitro gastric H(+), K(+)-ATPase activity at equieffective concentrations to that of BuF. The results indicate that C. glazioui constituents inhibit the gastric proton pump; this effect may account for the effective antisecretory and antiulcer activities of the standardized plant extract.

Screening for antifungal, DNA-damaging and anticholinesterasic activities of Brazilian plants from the Atlantic Rainforest: Ilha do Cardoso State Park

Crude extracts from 17 plant species collected from an Atlantic Forest region in the State of Sao Paulo (Brazil) have been screened for antifungal, DNA-damaging and acetylcholinesterase inhibiting activities. Of the 34 extracts obtained from leaves and stems of plants assayed for antifungal activity with Cladosporium sphaerospermum and C. cladosporioides 26.5% were active. However, only the extract of leaves of Cabralea canjerana showed a strong inhibition of both fungi. The DNA-damaging assay with mutant strains of Saccharomyces cerevisiae resulted in 11.7 % of the extracts being active whereas 100% of them showed selectivity for the DNA-repair mechanism of topoisomerase II. Of the 17 species analysed, 12 showed anticholinesterasic activity in TLC assay. However, only extracts from Tetrastylidium grandifolium (stems) and Sloanea guianensis (leaves and stems) inhibited acetylcholinesterase activity more than 50% in quantitative assay.

Sympathomimetic effects of Scoparia dulcis L. and catecholamines isolated from plant extracts

The herb Scoparia dulcis L. is used in Brazilian folk medicine to treat bronchitis, gastric disorders, haemorrhoids, insect bites and skin wounds, and in oriental medicine to treat hypertension. A previous study has shown that extracts of S. dulcis have analgesic and anti‐inflammatory properties; in this work the sympathomimetic activity of an ethanolic extract of Scoparia dulcis L. has been investigated in rodent preparations in‐vivo and in‐vitro.

Antinociceptive and antiinflammatory activities of the aqueous extract and isolated Cuphea carthagenensis (Jacq.) J. F. Macbr.

The aqueous extract (AE) and isolated fraction (ppt-3) of Cuphea carthagenensis (Jacq.) J. F. Macbr (sete-sangrias) were tested using models of nociception and inflammation in mice. Oral administration (p.o.) of the AE (10 to 100 mg/kg) and fraction ppt-3 (0.1 to 10 mg/kg) reduced the acetic acid-induced writhing in mice by 40 to 50% and by 46 to 70% of control, respectively. At the same doses AE and ppt-3 did not affect the tail flick response. Fraction ppt-3 also reduced the carrageenininduced paw edema, but at a dose 1000 times higher than that inducing antinociception. The results indicated the presence in the plant of antinociceptive constituents devoid of antiinflammatory activity, with actions apparently mediated by non-opioid mechanisms.