Comparison of Standardized Dichloromethane with Aqueous Pterodon pubescens Benth. Fruit Extracts on Antinociceptive and Anti-Inflammatory Activity

Abstract

Pterodon pubescens Benth., popularly known as "sucupira", is traditionally used as pain healing agent for many inflammatory diseases. The present study evaluated the in vivo antinociceptive and anti-inflammatory properties of sucupira's fruit dicloromethane extract (Pp) compared to the aqueous extract (Ppa) traditionally used in folk medicine. Extracts' chemical characterization was performed by gas chromatography coupled to mass spectra (GC-MS) detection. The standardized extracts were evaluated using antinociceptive and anti-inflammatory experimental models with mice. The results reported herein allowed establishing a relationship between the popular use of Pterodon pubescens fruit for pain relief and the activity of two major compounds isolated from this species which demonstrated antinociceptive activity. The experimental models corroborate activity of aqueous extract antinociceptive and anti-inflammatory activity, with lower potency compared to dichloromethane extract. Nevertheless the resulting data corroborates sucupira's folk use for pain relief.Keywords: Pterodon pubescens Benth., antinociceptive, furanditerpenes, sucupira, biological and pharmacological activities IntroductionThe study of inflammatory pain has been one of the most rapidly advancing and expanding areas of pain research. The chronic rheumatoid arthritis affects approximately 0.5-1% of the population, being among the main causes of adult disabilities characterized by spontaneity as well as lowered pain thresholds and increased sensitivity to pressure and temperature. [1][2][3][4][5] Chronic pain differs from acute pain not only in onset and duration, but more importantly in the underlying mechanisms, poorly responding to the usual drugs for acute pain. In order to improve chronic pain diseases treatment, a clear understanding of what leads to such persistent pain (visceral, inflammatory, and neuropathic) is required. Therefore testing pharmacological agents in such settings is the best way to explore new drug leads for chronic pain relief. An important source for this purpose is medicinal plants. 6 Pterodon pubescens' fruit decoction is widely used in Brazilian folk medicine for treatment of several chronic diseases such as rheumatism and arthritis. 7,8 The pharmacological properties of extracts, fractions and compounds obtained from P. pubescens have been reported for anti-parasitic, antitumor, anti-inflammatory, and antinociceptive activities.7-25 However, there is no scientific evidence reported concerning the antinociceptive and anti-inflammatory effectiveness of the aqueous extract or data supporting the ethno pharmacological use. Therefore, herein the differences in chemical profile, in vivo analgesic and anti-inflammatory properties of Freeze-dried fruit (100 g) were ground prior to use in a Stephen mill (model UM 40) and extracted with dichloromethane by soxhlet extraction system using a 1:3 ratio on mass basis (ground fruit:solvent). Subsequently the extract was concentrated under vacuum (Buchi RE 120) yielding 32% crude extract....