Inhibition of alpha-amylase by insulin plant (Myrcia sphaerocarpa DC) extracts: an alternative for the treatment of diabetes mellitus?

Abstract

Diabetes mellitus is an important medical-economical-social problem requiring up search for less costly alternatives for treatment, such as use of medicinal plants. Of the species cited in ethnobotanical studies, the "insulin plant" (Myrcia sphaerocarpa DC) appears among those used by diabetics. The objective of this work was to evaluate the inhibitory activity of alpha-amylase by aqueous extracts of "insulin plant", prepared by different methods at a proportion of 1:200 (w:v), for information about the alleged hypoglycemic effect. For this, five samples of commercially teas "insulin plant" were obtained; aqueous extracts were prepared; and thereafter, they were tested for inhibition of alpha-amylase, before and after exposure to simulated gastric fluid. Results demonstrated before exposure to gastric fluid, a significant inhibition of enzyme activity (greater than 50%) in the samples A and C, using the decoction and sample E in all methods of extraction. Comparing methods of extraction, the decoction was more effective. After exposure to gastric fluid, there was a reduction in the activity of enzyme inhibition, suggesting negative influence of low pH on the properties of the inhibitor. These results do not elucidate the mechanism of the hypoglycemic action reported in folk medicine and literature, but indicate a promising path.

Inhibition of α-glucosidase, pancreatic lipase, and antioxidant property of Myrcia hatschbachiiD. Legrand containing gallic and ellagic acids

“…Infusions made from the leaves or whole plants of these species are used to treat diabetes (Cascaes et al, 2015). Species of this genus demonstrated in vitro inhibitory activity of key diabetes targets, such as α-amylase and α-glucosidase (Oliveira & Pereira, 2015;González et al, 2016;Lima et al, 2018), and in addition some species showed hypoglycemic effects in vivo (Pepato et al, 1993;Miura et al, 2006;Vareda et al, 2014). The genus also has other medicinal properties: Myrcia tomentosa showed antimicrobial activities (Sa et al, 2017), Myrcia rostrata showed antinociceptive effects (Silva et al, 2018), Myrcia bella, Myrcia fallax, and Myrcia guianensis presented cytotoxic and antioxidant properties (Santos et al, 2018).…”

Indicadores Físico-Químicos E Componentes Antioxidantes De Duas Plantas Medicinais Com Alegações Antidiabéticas Da Amazônia

“…planta possui efeito hipoglicemiante potencial para o tratamento do diabetes, sendo a folha a parte mais utilizada para tal terapêutica, o extrato não apresenta citotoxicidade significativa em fibroblastos humanosPEREIRA, 2015).As folhas de Pedra Ume Caá são usadas frequentemente para o tratamento da síndrome diabética, com o seu início de uso localizado na Amazônia e posteriormente difundido pelo Brasil inteiro. Tal vegetal é tipicamente brasileiro, com desenvolvimento desde o Estado do Pará até o Rio Grande do Sul.…”