Psittacanthus plagiophyllus Eichl. (Loranthaceae): Perfil fitoquímico, efeito gastroprotetor e toxicidade aguda / Psittacanthus plagiophyllus Eichl. (Loranthaceae): Phytochemical profile, gastroprotective effect and acute toxicity

Psittacanthus plagiophyllus (Loranthaceae) é uma das espécies utilizadas no distrito de Alter do Chão, Santarém - PA, para o tratamento de gastrite. Levando em consideração o uso popular desta espécie, aliado à ausência de estudos farmacológicos e à sua grande disponibilidade nas savanas de Alter do Chão, o objetivo deste trabalho foi investigar o possível efeito gastroprotetor dos extratos aquoso e hidroalcoólico das folhas de P. plagiophyllus contra lesões gástricas induzidas por etanol em ratos, além de sua toxicidade aguda em ratos e de seu perfil fitoquímico por Cromatografia em Camada Delgada. No perfil cromatográfico dos extratos foi identificada a presença de flavonoides, taninos hidrolisáveis e cumarinas. O extrato aquoso de P. plagiophyllus nas doses de 500 e 1000 mg/Kg e o hidroalcoólico na dose de 500 mg/Kg inibiram significativamente a formação de lesões gástricas induzidas por etanol em ratos, quando comparados ao grupo controle, pelo teste de Dunnett (p<0,05). No ensaio de toxicidade aguda não foram observados sinais tóxicos de caráter geral e nem morte dos animais até a dose de 5000 mg/Kg dos extratos, o que indica baixa ou nenhuma toxicidade. Os compostos fenólicos detectados em P. plagiophyllus podem estar relacionados ao efeito gastroprotetor evidenciado.(AU)

Psittacanthus plagiophyllus (Loranthaceae) is one of the many species used in the district of Alter do Chão, Santarém - PA for the treatment of gastritis. Considering the popular use of this species, combined with the absence of pharmacological studies and its wide availability in the savanna of Alter do Chão, the aim of this study was to investigate the possible gastroprotective effect of hydroalcoholic and aqueous extracts of P. plagiophyllus leaves against ethanol-induced gastric lesions in rats, in addition to its acute toxicity in rats and phytochemical profile by Thin Layer Chromatography. The chromatographic profile of the extracts showed the presence of flavonoids, hydrolysable tannins and coumarins. The aqueous extract of P. plagiophyllus at doses of 500 and 1000 mg/Kg and hydroalcoholic at a dose of 500 mg/Kg significantly inhibited the formation of ethanol-induced gastric lesions in rats compared to the control group by the Dunnett's test (p <0.05). In the acute toxicity test were not observed signs of general toxic and no death of the animal to 5000 mg/Kg of the extracts, indicating low or no toxicity. Phenolic compounds found in P. plagiophyllus may be related to evidenced gastroprotective effect.(AU)

Toxicological studies of two compounds isolated from Loranthus globosus Roxb.

The sub-acute toxicities of two compounds 3,4-dimethoxycinnamyl alcohol (1) and 3,4,5-trimethoxycinnamyl alcohol (2) isolated from the plant Loranthus globosus Roxb were studied on long Evan's rats. The studies included the gross general observation such as changes in body weight, haematological profiles [total count of Red Blood Cells (RBC) and White Blood Cells (WBC), differential count of WBC, platelet count and Haemoglobin (Hb)%], biochemical parameters of blood [Serum Glutamate Oxaloacetate Transaminase (SGOT), Serum Glutamate Pyruvate Transaminase (SGPT), Serum Alkaline Phosphatase (SALP), urea and creatinine) and histopathology of the liver, kidney, heart and lung of both control and experimental groups of rats. The changes in haematological and biochemical parameters were statistically not significant after the administration of compounds 1 and 2 in a dose of 300 microg/rat/day for consecutive 14 days. No abnormality was found in the histopathology of the liver, kidney, heart and lung in the experimental groups of rats following same dose when compared with control group. This preliminary study suggests that the isolated compounds may be used safely for clinical trial.

[Is there any point to eradicate Phragmanthera capitata parasitizing African rubber trees?]. / Faut-il éradiquer Phragmanthera capitata, parasite des hévéas en Afrique?

The effect of Phragmanthera capitata (Sprengel) Balle, an epiphytic Loranthaceae, on latex production of three clones of rubber tree, Hevea brasiliensis (Müll. Arg.), was studied in the industrial plantation of Mitzic, in Gabon. The 22-year-old trees, presenting the largest trunk circumference, were the most parasitized and at the same time the best producers of latex. At first, this would suggest that mistletoe parasitism could have a favourable effect on latex yield. However, an accurate statistical analysis showed that, in fact, parasitism had no significant effect on latex yield. These data, discussed in relation to the biology of flowering parasitic plants, suggest that there is no urgency to eradicate Phragmanthera capitata for the moment.