Antiproliferative activity in tumor cell lines, antioxidant capacity and total phenolic, flavonoid and tannin contents of Myrciaria floribunda

ABSTRACT Myrciaria floribunda (H. West ex Willd.) O. Berg, Myrtaceae, is a native plant species of the Atlantic Rain Forest, from north to south of Brazil. The lyophilized ethyl acetate extract from the leaves of M. floribunda was investigated for its antiproliferative activity in tumor cell lines, antioxidant capacity and its total phenolic, flavonoid and tannin contents. Antiproliferative activity was tested in vitro against seven human cancer cells and against immortalized human skin keratinocytes line (HaCat, no cancer cell). Antioxidant activity was determined using 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and oxygen radical absorbing capacity (ORAC) assays and total phenolic, flavonoid and tannin contents were determined by spectrophotometric techniques. Ethyl acetate extract of M. floribunda exhibited antiproliferative activity against cancer cell lines with total growth inhibition (TGI) between 69.70 and 172.10 µg/mL. For HaCat cell, TGI value was 213.60 µg/mL. M. floribunda showed a strong antioxidant potential: EC50 of 45.89±0.42 µg/mL and 0.55±0.05 mmol TE/g for DPPH and ORAC, respectively. Total phenolic content was 0.23±0.013g gallic acid equivalents (GAE)/g extract and exhibited 13.10±1.60% of tannins content. The content of flavonoid was 24.08±0.44% expressed as rutin equivalents. These results provide a direction for further researches about the antitumoral potential of M. floribunda

Ethno-pharmacological relevance/features of some latin american wild medicinal plants, in ethnopharmacology of wild plants

The traditional herbal healers, along with wild medicinal plants and the knowledge they have about them, in certain regions of Latin America, are the prevalent alternatives for some people/communities to cover any primary health care requirements (e.g., treatment to prevent/improve/release pain/symptoms/disorders/diseases). traditional (plant-based) medicine has gained worldwide acceptance because the plants used for this purpose have been apparently efficacious and safe for a long time (decades/centuries), these being some reasons why the WHO created the traditional, complementary and integrative unit. (WHO 2019). Despite this, it is important to remember (i) what “ethnopharmacology” studies are about, which are, shortly, the uses, possible action modes, and bioproperties of plant-based preparations; and (ii) the contribution made by phytochemistry and pharmacology along with other related sciences (botany, pharmacy, microbiology, virology, parasitology, etc.) to find/check any biologically active drugs (molecules/fractions/extracts). In that sense, traditional medicine systems need more evidence-based studies that allow establishing the pharmacological potential together with the validation of therapeutic uses of medicinal plants and its chemical constituents [isolated or mixtures (fractions/extracts)] in such a way that safety and effectiveness are verified, as well as to reveal/understand their preventive and/or therapeutic mechanisms (Mukherjee et al. 2010, Schmidt and Klaser-Cheng 2017)