Teor de polifenóis e avaliação dos efeitos do extrato seco de folha de maracujá azedo (Passiflora edulis sims) sobre a glicação de colágeno e a ativação plaquetária em ratos diabéticos

Abstract

The search for medicinal plants with potential for pain relief and even cure diseases has expanded in several countries, including Brazil. Brazil is a major producer of passion fruit, which is beyond the nutritional value of its fruit, also been used for therapeutic purposes in folk medicine. In addition to the various applications of tea leaves passion in folk medicine, some authors have also suggested the hypoglycemic activity, antioxidant, antiplatelet and anti-platelet glicante for leaf extracts obtained from different species of passion fruit. However, the modulatory role of dry crude extract of leaves P. edulis Sims on protein glycation and platelet activation is not fully understood. Diabetes mellitus is considered as a major public health problem due to its high prevalence, the development of disabling chronic complications and the high economic costs generated by their treatment. Studies carried out with different experimental models have shown that DM leads to platelet activation with consequent increase of aggregation as well as increased glycation of proteins, and these changes directly involved in the biochemical pathways leading to the development of major chronic complications induced by DM . Thus, the present work had as main objective to determine the content of total polyphenols and evaluate the effects of dry extract of Passiflora edulis Sims on biochemical markers of collagen glycation, activation and platelet aggregation in diabetic rats. Male Wistar rats (300±25g) were treated with alloxan (150mg/kg body weight dissolved in 0.9% saline) intraperitoneally. The fresh leaves of passion fruit were collected in Alfenas-MG (21° 27’ 33’’ S; 46° 01’ 59’’ w; Altitude 789 m) and identified at the Federal University of Lavras-MG. The dry extract was obtained by grinding in a hydroethanolic solution 70% (V/V), followed by evaporation under reduced pressure and lyophilization and administered (200mg dry extract / kg) to normal and diabetic rats, for ninety days. The control group received water only. Platelet aggregation was performed in aggregometer PA-04 Qualiterm Eletronica to 37°C. Biochemical markers were determined in serum by enzymatic method. The collagen glycation content will be performed by fluorescence. The oxidant species production was monitored by chemiluminescence. The administration of dry extract of Passiflora edulis Sims leaves reduced fasting glucose and HbA1C levels in the blood of diabetic animals . The dry extract administration of Passiflora edulis Sims prevented the increase of serum creatinine levels of diabetic animals. The dry extract of Passiflora edulis Sims was able to reduce the concentration of atherogenic lipoproteins in the serum of treated animals. Diabetic animals had higher basal production of oxidants and platelet aggregation compared to non-diabetic animals. Treatment of diabetic animals with the extract of Passiflora edulis Sims attenuated the effects of diabetes on oxidant production and platelet aggregation. The AGEs levels determined in samples obtained from tendon collagen from diabetic rats was higher than in non- diabetic animals and the treatment of diabetic animals with dry extract led to a reduction of collagen glycation.