Antioxidant, cytotoxic and UVB-absorbing activity of Maytenus guyanensis Klotzch. (Celastraceae) bark extracts

Abstract

Maytenus guyanensis Klotzch. is an Amazonian medicinal tree species known in Brazil by the common name chichuá and in Peru and Colombia by the name chuchuhuasi. It is used in traditional medicine as stimulant, tonic, and muscle relaxant, for the relief of arthritis, rheumatism, hemorrhoids, swollen kidney, skin eruptions, and skin cancer prevention, among others. Initially, different extraction solvents and methods were applied to dried, ground bark which made possible the preparation of extracts having both significant lethality to brine shrimp larvae (Artemia franciscana Leach) as well as antioxidant activity in vitro based on tests involving reactions with 2,2,-diphenyl-1-picrylhydrazyl (DPPH). Analysis of fractions from serial extractions with solvents of increasing polarity supports the notion that antioxidant activity is associated with compounds of intermediate polarity and cytotoxicity is associated with compounds of low to intermediate polarity. Variation of extraction time and conditions revealed that hot, continuous ethanol extraction provided good yields of bark extract in several hours. Hot extraction also provided ethanol extracts having greater lethality to brine shrimp and antioxidant activity (compared to the flavonoid rutin in semi-quantitative methods based on DPPH) than extracts obtained from maceration at room temperature. Freeze-dried ethanol extracts were prepared by: 1) maceration at room temperature and 2) hot extraction (eight hours) on several hundred gram scales and the latter extract was shown to have partial screening effects on UVB light. In this work, cytotoxic, antioxidant and potential sun-screening activity are shown for the first time in M. guyanensis.

Evaluation of the Antioxidant Action and Flavonoid Composition ofArtemisiaSpecies Extracts

“…Alcohol solution of DPPH is a purple colored that, after being reduced by an antioxidant turns into a yellow product. The use of DPPH provides an easy and rapid way to evaluate antioxidant activity (4,7,11).…”

Evaluation of antimicrobial activity and toxic potential of extracts and triterpenes isolated from Maytenus imbricata

“…Thus, it is possible to assign the high cytotoxicity observed for these two extracts to compound 5. Using Artemia franciscana, Macari et al 33 studying Maytenus guyanensis found LC 50 = 363 μg/mL for the hexane extract of barks. Based on this LC 50 , these authors considered this extract as being a potential larvicide product.…”

Screening of the in vitro antileishmanial activities of compounds and secondary metabolites isolated from Maytenus guianensis Klotzsch ex Reissek (Celastraceae) chichuá Amazon

“…Numerous species of Amazonian plants have medicinal properties, including those belonging to the therapeutically important Celastraceae family; these have a range of pharmacological activities such as anti-ulcer, insecticide, immunosuppressant, anti-rheumatic, antibacterial, anti-parasitic, and anti-cancer effects (11) (12) (13) . In Brazil, this family is represented by four genera: Austroplenckia, Franhofera, Maytenus, and Salacia (14) .…”

“…The Maytenus genus is the largest of these and approximately 200 species have been identified in Brazil (15) , representing almost 40% of the known Maytenus species (16) . In the Northern Amazon region, the Maytenus guianensis species in particular has been used in traditional medicine for the treatment of various diseases and for its antiparasitic effects (12) (17) . The present study therefore aimed to conduct an in vitro screening of the antileishmanial activities of extracts and compounds isolated from M. guianensis.…”