Caracterização da composição química e estudo farmacodinâmico do extrato de folhas de Alpinia zerumbet (Colônia)

Abstract

The use of herbal medicines by the population of developing countries plays an important role in the treatment of various diseases. According to the World Health Organization (WORLD HEALTH ORGANIZATION, 2013), approximately 80% of the population of these countries use such treatments as the first option. In this scenario, high blood pressure is considered a global public health problem, affecting more than 1 billion people worldwide, with potential risk of heart attacks and strokes (WORLD HEALTH ORGANIZATION, 2013). In the context of folk medicine, the use of Alpinia zerumbet (AZ), commonly called “Colônia”, is widely known for its diuretic and antihypertensive properties. Thus, the objective of this research was to characterize the chemical components of different types of extracts (aqueous and hydro alcoholic) of green or dry leaves of “Colônia”, and to study its antihypertensive and vasodilatory effect. The vasodilator effects of AZ from different extraction conditions were studied in the perfused mesenteric vascular bed, and total polyphenol content (TPC) was determined for all samples. UHPLC/ESI-QTOF-MS analysis established the chemical composition of AZ extracts, and a molecular network from GNPS generated a list of putative compounds. Briefly, results show a 50% hydroethanolic extract from fresh leaves (AZE4) as the best extraction condition, presenting the greatest vasodilator effect (ED50 = 7.1 μg ± 1.73) and TPC (16.30 mg GAE/g ± 0.44). Flavonoids are the main constituents and alpinetin, kaempferol-3-O-glucuronide, (-)- epicatechin, and pinocembrin were identified as major compounds. The least effective extraction condition was 50% hydroethanolic extract from dried leaves without heating. This extract showed the smallest vasodilator response (ED50 = 29.1 μg ± 4.3) and TPC (6.35 mg GAE/g ± 0.08), reinforcing the use of fresh leaves and heating step to improve extracts performance. The vasodilator effect and the main flavonoid composition of AZE4 provide experimental support, suggesting this extract as a potential source of bioactive flavonoids to treat cardiovascular diseases, such as arterial hypertension.