Abstract

Urera baccifera (Urticaceae) is a shrub used in folk medicine for rheumatic diseases and mycosis. This study aimed to test the antiviral, antinociceptive, anti-inflammatory and antimicrobial activities of U. baccifera leaves and roots. The cytotoxic and antiviral activity was evaluated against Herpes virus type 1, in vitro. The antimicrobial activity was determined by the broth microdilution method based on Clinical and Laboratory Standards Institute (CLSI) M27-A3, M38-A2 and M7-A6 standardized reference method. In vivo anti-inflammatory and antinociceptive activity were evaluated in ear edema measurement, complete Freund’s adjuvant-induced nociception, measurement of cold allodynia and spontaneous nociception in male adult Swiss mice. U. baccifera roots and leaves presented anti-herpetic activity. The plant extract, predominantly the ethyl acetate and butanol fractions, also inhibit Klebsiella pneumoniae, Prototheca zopfii and Saccharomyces cerevisiae and did not show antinociceptive and anti-inflammatory effect on the tested experiments. The presence of biologically active products and the low cytotoxicity demonstrated by the extract and fractions of U. baccifera makes these extracts promising antiviral candidates. This nettle can also be considered a moderated antimicrobial agent against K. pneumoniae, P. zopfii and S. cerevisiae. However, antinociceptive and anti-inflammatory effects to the samples in this study were not observed.

Key words: Stinging nettle, herpes simplex type 1, Urticaceae, Klebsiella pneumonia, Prototheca zopfii, Saccharomyces cerevisiae.

Abbreviation

ACV, Acyclovir; ATCC, american type culture collection; BuOH, butanol fraction; CC₅₀, cytotoxic concentration 50% (µg/ml); CE, crude extract; CFA, complete freund’s adjuvant; CHCl₃, chloroform fraction; DMSO, dimethyl sulfoxide; EtOAc, ethyl acetate fraction; FBS, fetal bovine serum; HSV, herpes simplex virus; HSV-1, Herpes simplex type 1; HSV-1-ACVR, acyclovir- resistant Herpes simplex virus type 1; IC₅₀, inhibitory concentration; (µg/ml); i.pl., intraplantar (plantar surface); MNCC,   maximum   noncytotoxic   concentration;  SD, standard deviation; SI, selectivity index; TCID₅₀, 50% tissue culture infectious doses.