Avaliação da atividade antiedematogênica, antimicrobiana e mutagênica das sementes de Amburana cearensis (A. C. Smith) (Imburana-de-cheiro) / Assessment of the antiedematogenic, antimicrobial and mutagenic activity of Amburana cearensis seeds (A.C. Smith) (Imburana-de-cheiro)

Foram avaliados os efeitos antiinflamatório, antibacteriano e mutagênico do extrato aquoso das sementes de Amburana cearensis. A atividade antiinflamatória foi avaliada em modelo de edema de pata induzido por carragenina, utilizando o extrato em concentrações de 10 % e 20 % nos grupos experimentais; AAS 10 mg/kg (v.o) no grupo padrão e água destilada no grupo controle. A atividade antimicrobiana foi determinada através do método de diluição em Agar, utilizando concentrações de extrato de 10 %, 7,5 %, 5 %, 2,5 % e 1 % em cepas de Sthaphylococcus aureus ATCC 27853, Escherichia coli ATCC 25922 e Pseudomonas aeruginosas ATCC 25923) e a atividade mutagênica foi determinada pelo teste de Allium cepa, utilizando extrato em concentrações de 0,02 mg/mL, 0,1 mg/mL e 0,5 mg/mL. O extrato aquoso das sementes de Amburana cearensis nas concentrações de 10 % e 20 % apresentou efeito antiedematogênico, estatisticamente significativo a partir de duas horas após administração do flogógeno, e tal efeito persistiu até 24 horas após a indução da resposta inflamatória. Quanto à atividade antibacteriana, o extrato não apresentou ação contra as cepas bacterianas de Sthaphylococcus aureus, Escherichia coli e Pseudomonas aeruginosas nas concentrações testadas. A análise dos resultados do teste de Allium cepa evidenciou ação tóxica (em concentração de 0,5 mg/mL) e mutagênica (micronúcleo 0,1 mg/mL e aberrações cromossômicas 0,1 mg/mL e 0,5 mg/mL) do extrato de Amburana cearensis em células meristemáticas de Allium cepa. Tais resultados sugerem potencial aplicação terapêutica no tratamento da inflamação. Contudo, também demonstram a necessidade de estudar para comprovar a segurança na utilização dessa espécie.

The anti-inflammatory, antibacterial and mutagenic effects of the aqueous extract of Amburana cearensis seeds were evaluated. The anti-inflammatory activity was evaluated by a paw edema model induced by carrageenan, using the extract at 10 % and 20 % concentrations in the experimental groups: AAS 10 mg/kg (orally administrated) in the standard group and distilled water in the control group. The antimicrobial activity was determined by the agar dilution method, using extract concentrations of 10 %, 7.5 %, 5 %, 2.5 % and 1% in strains of Staphylococcus aureus ATCC 27853, Escherichia coli ATCC 25922 and Pseudomonas aeruginosas ATCC 25923), and the mutagenic activity was determined by the Allium cepa test using extract concentrations of 0,02 mg/mL, 0,1 mg/mL and 0,5 mg/mL. The aqueous extract of Amburana cearensis seeds at 10 % and 20 % concentrations had an statistically significant antiedematogenic effect two hours after administering the flogogen, and this effect persisted for up to 24 hours after inducing the inflammatory response. Regarding the antibacterial activity, the extract showed no action against the bacterial strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosas at the concentrations tested. The results of the Allium cepa test showed the toxic (at a concentration of 0,5 mg/mL) and mutagenicity (0.1 mg/mL micronucleus and 0.1 mg/mL and 0.5 mg/mL chromosomal aberrations) actions of the Amburana cearensis extract on meristematic cells of Allium cepa. These results suggest potential therapeutic applications to treat inflammations. However, they also show the need for further studies to demonstrate the safe use of this species.

Antiulcerogenic activity of Combretum leprosum.

This study investigates the effects of an ethanolic extract from the stem bark of Combretum leprosum Mart. & Eiche (Combretaceae) on experimental ulcers induced by ethanol and indomethacin and on gastric secretion and mucus content in pylorus-ligated rats. The effects were compared with those of ranitidine and carbenoxolone. Combretum leprosum orally administered elicited a complete inhibition of the appearance of gastric lesions induced by ethanol and a partial reduction when indomethacin was used as an ulcerogenic agent. Moreover, the protection against gastric ulceration induced by ethanol was decreased with indomethacin pretreatment. The intraduodenal administration of Combretum leprosum in four-hour pylorus-ligated rats increased the volume and pH of gastric juice while decreasing the acid output and produced a significant increase in gastric wall mucus content. The major compounds detected in a preliminary phytochemical screening were triterpenes, flavonoids, taninns and saponins. This study provides evidence that the ethanolic extract of Combretum leprosum possesses gastroprotective and anti-ulcerogenic effects, which are related to the inhibition of the gastric acid secretion and an increase of mucosal defensive factors such as mucus and prostaglandin.

Chronic propranolol treatment causes desensitization of the steroidogenic response in testicular interstitial cells but does not alter protein kinase C.

We investigated effects of chronic propranolol treatment on the secretory response of rat testicular interstitial cells (testosterone secretion) to subsequent in vitro stimulation with activators of protein kinase-C (PK-C) (L-propranolol, phorbol 12, 13-dibutyrate (PDBu), LHRH) or activators of protein kinase A (PK-A), (hCG or dibutyryl cAMP (dbcAMP)). We determined [3H]PDBu binding and PK-C activity in these cells. Treatment of rats with propranolol (Inderal 500 mg/L of water for 5 weeks) reduced by 48%, 50% and 29% the L-propranolol-, LHRH- or PDBu-induced testosterone secretion, respectively, when compared to cells from controls. This desensitization in testosterone secretion in vitro was also present when the testicular interstitial cells were stimulated with hCG or dbcAMP (secretion decreased by 65%/57%, respectively, when compared to cells from control rats). Challenging the cells originated from rats that received propranolol chronically with the addition in vitro of propranolol resulted in an additional reduction of the hCG/dbcAMP-stimulated testosterone secretion. Chronic propranolol-induced desensitization was not associated with a loss in [3H]PDBu binding or a decrease in PK-C activity. Chronic propranolol-induced desensitization can be uncoupled from down-regulation of protein kinase C. The effector responsible for the desensitization could be distal to the protein kinase C and protein kinase A.

Propranolol stimulates testicular interstitial fluid formation and testosterone secretion in rats

We investigated the effect of intratesticularly injected propranolol on testicular interstitial fluid (TIF) formation and on testosterone levels in the TIF of intact adult male Wistar rats (4-9 rats per group). D1-propranolol at doses of 0.6, 1.2 or 6.0 mg/kg was injected into the left (L) testis whereas the right (R) testis (control testis) received vehicle. d1-propranolol (6.0 mg/kg) caused a significant increase in both TIF volume (329 per cent) and TIF levels of testosterone (257 per cent) in the L testis but not in the R (control) testis 3 h post-injection. In rats treated simultaneously with human chorionic gonadotropin (hCG, 5 IU/rat, sc) the same dose of propranolol (6.0 mg/kg) significantly increased the stimulatory effect of hCG on testosterone secretion by 1.8-fold, but hCG did not modify the stimulatory effect of propranolol on TIF volume. These results demonstrate a direct stimulatory effect of propranolol on TIF volume and testosterone secretion, both under basal and hCG-stimulated conditions.