Composição química e avaliação biológica de óleo essencial e composto isolado das folhas de Psidium guineense Swartz (Myrtaceae)

Abstract

The leaves of Psidium guineense Swartz are used in folk medicine for the treatment of inflammatory processes. However, there is no scientific evidence to demonstrate this activity. This study consisted in evaluating the antioxidant, anti-inflammatory, antiproliferative and antimicrobial activities of the essential oil of P. guineense and majoritarian compound. The essential oil (EOPG) was extracted from the leaves of P. guineense by hydrodistillation and analyzed by gas chromatography-mass spectrometry (CG-MS). The major compound (PG-1) was isolated by column chromatography and identified by nuclear magnetic resonance (NMR). The antioxidant activity of EOPG and PG-1 was evaluated in vitro by the DPPH, ABTS and MDA methods. The antiinflammatory potential was assessed using two models, including pleurisy and carrageenan-induced paw edema in mice. The impact of EOPG and PG-1 on cell proliferation was determined by spectrophotometric quantification of the cellular protein content using a sulforhodamine B assay and the antimycobacterial activity against Mycobacterium tuberculosis was determined using the REMA method. 38 compounds were identified in EOPG, the main constituent being sesquiterpene spathulenol (PG-1) (80.7%). EOPG and PG-1 exhibited the most relevant antioxidant activities by DPPH and MDA methods compared to reference standard, with IC50 values ranging from 26.13- 85.60 μg/mL. Oral administration of EOPG and PG-1 showed significant inhibition in carrageenin-induced foot paw edema and also in the pleurisy model. EOPG (GI50 = 0.89 μg/ml) and PG-1 (GI50 = 49.30 μg/ml) were particularly effective against the ovarian cancer cell line. Both had moderate antimycobacterial activity. This study demonstrated for the first time the antioxidant, anti-inflammatory, antiproliferative and antimycobacterial properties of the essential oil of P. guineense (leaves collected in Dourados-MS) and of spathulenol, collaborating with the ethnopharmacological use of this species due to its effect anti-inflammatory.