Acute and sub-chronic (28 days) oral toxicity evaluation of tincture Baccharis trimera (Less) Backer in male and female rodent animals.

The infusion of Baccharis trimera (Less) DC, popularly known as "carqueja" (broom), is popularly used in the treatment of hepatic and digestive problems. In this study, we evaluated the acute and sub-chronic oral toxicities of B. trimera tincture on male and female Wistar rats according to Organization for Economic Cooperation and Development (OECD, guidelines 423 e 407, respectively). The B. trimera tincture was administered by oral gavage in a single dose (2000 mg/kg) in doses of 100, 200 and 400 mg/kg daily for 28 days. Blood was collected to analyze hematological and biochemical parameters. Kidneys and liver were homogenized to determine lipid peroxidation and δ-aminolevulinate dehydratase (δ-ALA-D) and catalase (CAT) enzyme activities. In acute treatment, tincture did not induce any signs of toxicity or mortality. Daily oral administration produced no significant changes in the hematological and biochemical parameters, except for the hepatic enzymes alanine aminotransferase (ALAT) and aspartate aminotransferase (ASAT) that showed a reduction in both sexes. Moreover, the B. trimera tincture did not increase lipid peroxidation or affected ALA-D and CAT activities. In conclusion, the tincture of B. trimera may be considered relatively safe in this protocol.

Effects of chlorogenic acid, caffeine, and coffee on behavioral and biochemical parameters of diabetic rats.

Diabetes mellitus (DM) is associated with brain alterations that may contribute to cognitive dysfunctions. Chlorogenic acid (CGA) and caffeine (CA), abundant in coffee (CF), are natural compounds that have showed important actions in the brain. The present study aimed to evaluate the effect of CGA, CA, and CF on acetylcholinesterase (AChE), Na(+), K(+)-ATPase, aminolevulinate dehydratase (δ-ALA-D) activities and TBARS levels from cerebral cortex, as well as memory and anxiety in streptozotocin-induced diabetic rats. Animals were divided into eight groups (n = 5-10): control; control/CGA 5 mg/kg; control/CA 15 mg/kg; control/CF 0.5 g/kg; diabetic; diabetic/CGA 5 mg/kg; diabetic/CA 15 mg/kg; and diabetic/CF 0.5 g/kg. Our results demonstrated an increase in AChE activity and TBARS levels in cerebral cortex, while δ-ALA-D and Na(+), K(+)-ATPase activities were decreased in the diabetic rats when compared to control water group. Furthermore, a memory deficit and an increase in anxiety in diabetic rats were observed. The treatment with CGA and CA prevented the increase in AChE activity in diabetic rats when compared to the diabetic water group. CGA, CA, and CF intake partially prevented cerebral δ-ALA-D and Na(+), K(+)-ATPase activity decrease due to diabetes. Moreover, CGA prevented diabetes-induced TBARS production, improved memory, and decreased anxiety. In conclusion, among the compounds studied CGA proved to be a compound which acts better in the prevention of brain disorders promoted by DM.

Curcumin protects against cigarette smoke-induced cognitive impairment and increased acetylcholinesterase activity in rats.

Cigarette smoke, a widely spread habit, is associated with a decline in cognitive function and studies have demonstrated that curcumin (Cur), an Indian spice, possesses a strong neuroprotective potential. Considering the relevance of investigating dietary compounds this study aimed to investigate the effect of Cur on memory and acetylcholinesterase (AChE) activity in brain structures and blood of cigarette smoke-exposed rats. Male Wistar rats were treated with curcumin and cigarette smoke, once a day, 5 days each week, for 30 days. The experimental procedures were divided in two sets of experiments. In the first, the animals were divided into 4 groups: Vehicle (corn oil), Cur 12.5 mg/kg, Cur 25 mg/kg and Cur 50 mg/kg. In the second, the animals were divided into 5 groups: Vehicle (corn oil), Smoke, Smoke plus Cur 12.5 mg/kg, Smoke plus Cur 25 mg/kg and Smoke plus Cur 50 mg/kg. Treatment with Cur significantly prevented the decreased latency and cholinergic alterations in cigarette smoke-exposed rats. These AChE alterations could suggest a role in the memory impairment promoted by cigarette smoke-exposure and point toward the potential of Cur to modulate cholinergic neurotransmission and, consequently, improve cognition deficits induced by smoke. This study suggests that the dietary compound Cur may be involved in cholinergic system modulation and as a consequence exert an effect on learning and memory.

Syzygium cumini and the regeneration of insulin positive cells from the pancreatic duct

O Syzygium cumini é uma planta medicinal que tem sido utilizada popularmente para o tratamento da diabetes melito insulino dependente (DMID). Este estudo verificou o efeito do extrato da casca de Syzygium cumini sobre a regeneração de células insulino-positivas, a partir do ducto pancreático, no pâncreas de ratos normais e diabéticos. Os animais foram divididos em grupo controle (C), controle tratado (CT), diabético controle (DC) e diabético tratado (DT). Nos grupos tratados foi realizada a administração oral do extrato aquoso da casca de Syzygium cumini, na dose de 1g/kg de peso vivo. Após um período de 30 dias, os animais foram submetidos à eutanásia e o pâncreas retirado para análise imunohistoquímica. Neste estudo, foram visualizadas células insulino-positivas no ducto pancreático e no tecido conjuntivo próximo a ele, no pâncreas dos animais dos grupos DT e CT. Estes resultados indicam que o tratamento com o extrato da casca de Syzygium cumini na dose de 1g/kg estimula a formação de células insulino-positivas a partir das células epiteliais do ducto pancreático.

Extrato da casca de Syzygium cumini no controle da glicemia e estresse oxidativo de ratos normais e diabéticos / Syzygium cumini bark extract in controling glycemia and oxidative stress of normal and diabetic rats

O Syzygium cumini, também conhecido como Jamboläo é amplamente utilizado na medicina popular para o tratamento da diabetes melito. Este estudo verificou a eficiência do extrato da casca de Syzygium cumini sobre os níveis glicêmicos e estresse oxidativo de ratos normais e diabéticos induzidos por aloxano. Os animais foram divididos em grupo controle (C), controle tratado (CT), diabético controle (DC) e diabético tratado (DT). A administraçäo oral do extrato aquoso da casca de Jamboläo, na dose de 1g/kg de peso vivo, por um período de trinta dias, näo resultou em uma reduçäo significativa na glicemia e nos níveis de hemoglobina glicosilada. Neste estudo, o tratamento com o extrato demonstrou um aumento dos níveis de substâncias reativas ao ácido tiobarbitúrico (TBA-RS) no plasma dos ratos do grupo DT (P<0,05), comparado com o C. A atividade da catalase nos rins dos ratos do grupo DC diminuiu significativamente (P<0,01) e no fígado houve uma elevaçäo significativa dessa enzima no grupo DC (P<0,01). Estes resultados indicam que o extrato da casca do Jamboläo näo possui efeito hipoglicemiante em ratos diabéticos induzidos pelo aloxano. O efeito antioxidante desta planta näo foi suficiente para diminuir significativamente a produçäo de TBA-RS. A diminuiçäo da atividade da catalase nos rins pode ser devida à exaustäo ou inibiçäo desta enzima e seu aumento, no fígado, devido ao estresse oxidativo, ocasionado pelo estado diabético