Polyphenolic profile and pharmacological activities of whips horse (Luehea divaricata) bark extracts studied using in vitro and in vivo systems

Abstract

Leaves and barks of Luehea divaricata (Malvaceae) are used in folk medicine for the treatment of infectious diseases, tumors, rheumatism and diabetes. This work presents in vivo experiments (rats and mice) supported by in vitro and chemical analyses in order to address the above mentioned folk medicinal uses. The phenolic constituents of both aqueous and hydroalcoholic extracts are mainly catechin derivatives (135.4 and 215.9 mg/g, respectively). Both extracts displayed strong antioxidant activity. They also showed antiproliferative activities against tumor cells, nitric oxide synthesis inhibition (indicative of anti-inflammatory activity) and antimicrobial activity against a variety of infectious agents. Paracetamol-induced liver injury in rats, which has a high inflammatory component, was substantially attenuated in animals treated with the hydro-alcoholic extract (200 mg kg−1 day−1). This was deduced from aspartate aminotransferase and alanine aminotransferase measurements in plasma as well as from the hepatic activities of catalase and superoxide dismutase. Both extracts inhibited the pancreatic α-amylase with IC50 values of 11.50 ± 0.05 and 18.70 ± 3.87 μg/mL for the hydro-alcoholic and aqueous extract, respectively. Both extracts inhibited starch digestion in mice at the doses of 200 and 400 mg/kg. In general terms the results confirm several of the vox populi notions about the therapeutic potential of L. divaricata, the antidiabetic action, combined with the hepatoprotective effect, being the most relevant observations. Not less important is the economical perspective for the rural producers which may eventually increase their revenue by selling increasingly valued raw materials derived from L. divaricata based on its therapeutic properties.