Effect of Byrsonima sericea DC. leaf extracts on mice gastrointestinal tract.

Byrsonima sericea DC. (Malpighiaceae) leaves are popularly folk medicine in Brazil used to treat gastro-intestinal disorders including diarrhea and gastric diseases. Ethanol extract (BSEE), ethyl acetate extract (BSEAE) and hexane extract (BSHE) of the leaf part of Byrsonima sericea DC were characterized for their total phenolics, proanthocyanidins and flavonoids content. The total antioxidant capacity of extracts was determined. The ethnopharmacological use of B. sericea leaves was evaluated by assaying BSEE for gastroprotective activity in stomach ulcer induced by indomethacin, intestinal motility and toxicity. Abundance of phenols mainly tannins was found in BSEE. Total phenolics, flavonoids and proanthocyanidins content in BSEE were found to be 0.371, 0.172 and 1.3 × 10-4 (mg/g) respectively. BSEE showed concentration dependent significant scavenging of DPPH values 90.0 (%) respectively. Moreover, oral doses of 500 and 1000 mg/kg did not cause mortality, and there was no difference in animals weight, organs relative weight and alanine transaminase (ALT) and aspartate transaminase (AST), as compared to the control group. Doses of 250, 500 and 1000 mg/kg inhibited the gastric lesions induced by indomethacin in 52, 60 and 62 % respectively. The dose of 1000 mg/kg decreased intestinal motility in animals. The presence of phenolic compounds, including tannins could be associated with the anti-diarrheal action and the antioxidant properties could collaborate to the gastroprotective and anti- diarrheal activities, confirming its popular use of the plant.

Antispasmodic effects of a new kaurene diterpene isolated from Croton argyrophylloides on rat airway smooth muscle.

OBJECTIVES: The effects of rel-(1S,4aS,7S,8aS)-7-(1-vinyl)-tetradecahydro-1,4a-dimethylphenanthrene-7,8a-carbolactone-1-carboxylic acid (TCCA), a new ent-kaurene diterpene isolated from Croton argyrophylloides, on rat tracheal preparations were investigated. METHODS: Tracheae were removed and cut into two-cartilage segments that were mounted in organ baths containing Tyrode's solution. RESULTS: TCCA reduced the contractions induced by electrical field stimulation, relaxed K(+)-induced contractions, and inhibited both phasic and tonic components of the K(+)- and ACh-induced contractions. TCCA reduced the serotonin-induced contraction, abolished that evoked by K(+) in the presence of epinephrine, and also reduced the ACh-induced contractions under Ca(2+)-free conditions. TCCA blocked contractions that depend on divalent cation inflow through voltage-operated Ca(2+) channels (VOCCs) and receptor-operated Ca(2+) channels (ROCCs), but had greater potency to block VOCC- than ROCC-dependent contractions or contractions induced by ACh in Ca(2+)-free conditions. TCCA relaxed the phorbol 12,13 dibutyrate (1 µm) induced contraction, but with slight potency. CONCLUSIONS: TCCA induces an antispasmodic effect through several mechanisms including blockade of either VOCCs (with greater potency) or ROCCs, blockade of IP(3)-induced Ca(2+) release from sarcoplasmic reticulum (with intermediate potency) and reduction of the sensitivity of contractile proteins to Ca(2+).