ABSTRACT
Fifteen extracts from nine selected Argentine medicinal plants were tested for their antiplasmodial activity in vitro by assessing their ability to inhibit the uptake of [3H]-hypoxanthine into the Plasmodium falciparum K1 pyrimethamine/chloroquine resistant strain. The methanol extract of Satureja parvifolia showed good antiplasmodial activity (IC(50) 3 microg/ml). Inhibition of the growth of P. falciparum was also observed with aqueous extracts of Buddleja globosa and S. parvifolia.
Subject(s)
Antimalarials/pharmacology , Plants, Medicinal , Plasmodium falciparum/drug effects , Animals , Argentina , Drug Resistance , Inhibitory Concentration 50 , Plant Extracts/pharmacologyABSTRACT
Aerial parts of Achyrocline satureioides(Lam) D. C. (Asteraceae) are used in folk medicine as infusions or decoctions for the management of several diseases including gastrointestinal and hepatic disorders. These data and the presence of flavonoids and caffeoyl derivatives have led us to study its hepatoprotective and choleretic activities. The hepatoprotective activity was evaluated in the bromobenzene- (BB-) induced hepatotoxicity model in mice through the measurement of the serum levels of alanine-aminotransferase (ALT) and aspartate transaminase (AST), thiobarbituric acid reacting substances (TBARS) and glutathione levels. The aqueous extract of the aerial parts of A. satureioides administered before BB, at the dose of 300 mg kg(-1)p.o., demonstrated significant inhibition (P< 0.01) in the BB increase of liver ALT and AST and in the BB-induced increase of liver TBARS content. Also it was able to significantly increase (P< 0.05) the depleted levels of liver glutathione. In addition, at the same dose, a significant increase (P< 0.01) in the bile flow of rats was found. The results obtained with the aqueous extract of A. satureioides support its use in popular medicine as a hepatoprotective and digestive agent, and the effects might be mediated through the antioxidant and choleretic activities.
Subject(s)
Asteraceae , Bile/drug effects , Cholagogues and Choleretics/pharmacology , Liver/drug effects , Plant Extracts/pharmacology , Alanine Transaminase/metabolism , Animals , Aspartate Aminotransferases/metabolism , Bromobenzenes/toxicity , Female , Liver/metabolism , Liver/pathology , Malondialdehyde/metabolism , Medicine, Traditional , Mice , Rats , Rats, Wistar , Thiobarbituric Acid Reactive Substances/metabolismABSTRACT
Hypa A, a novel macrocyclic polypeptide containing 30 amino acid residues, has been isolated from the n-butanol extract of the Argentine plant Hybanthus parviflorus. The sequence, cyclo-(SCVYIPCTITALLGCSCKNKVCYNGIPCAE), was determined by automated Edman degradation, quantitative amino acid analysis and nanospray MS/MS(2). Three intramolecular disulfide bridges stabilize the cyclic peptide backbone of hypa A. Using these structural features to classify the peptide as a cyclotide, we extended the distribution of that substance class to a new genus, and now propose a uniform nomenclature for cyclotides.
Subject(s)
Peptides, Cyclic/chemistry , Rosaceae/chemistry , Amino Acid Sequence , Argentina , Disulfides/chemistry , Drug Stability , Mass Spectrometry/methods , Molecular Sequence Data , Peptides, Cyclic/isolation & purification , Terminology as TopicABSTRACT
Lipophilic and hydrophilic extracts of four Argentine plants (Gamochaeta simplicaulis Cabr. 1, Achyrocline flaccida Wein. D. C. 2, Eupatorium buniifolium H. et A. 3, and Phyllanthus sellowianus Muell. Arg. 4) were examined in vitro for their ability to inhibit the polymerase and ribonuclease H (RNase H) activities of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) (wild and Y181C mutant types). The active extracts were also examined as inhibitors of viral replication in HLT4LacZ-1IIIB cell cultures, evaluating their cytotoxicity in parallel. Infusions 2I and 4I, among the crude extracts, showed the highest activity. These extracts were refractioned into four fractions; 2I4 and 4I4 were active as inhibitors of DNA-polymerase (wild and Y181C types) and RNase H activities. These fractions were potent as inhibitors of viral replication and were not cytotoxic. Refractionation of 2I4 yielded five new fractions, two of which, 2I4-4 and 2I4-5, showed notable activity. Refractionation of 4I4 yielded for new fractions; of these, 4I4-3 and 4I4-4 were active. The marked biological activity found in the infusion of A. flaccida and P. sellowianus makes them sufficiently attractive to be considered in the combined chemotherapy of the disease.
Subject(s)
HIV Reverse Transcriptase/antagonists & inhibitors , Nucleic Acid Synthesis Inhibitors , Plant Extracts/pharmacology , Plants, Medicinal/chemistry , Reverse Transcriptase Inhibitors/pharmacology , Ribonuclease H/antagonists & inhibitors , Anti-HIV Agents/pharmacology , Cell Line , DNA-Directed DNA Polymerase/metabolism , Humans , Ribonuclease H/metabolismABSTRACT
The in vitro antiviral activity demonstrated by aqueous extract (AE) of Achyrocline flaccida on herpes simplex virus type-1 is exerted early during the viral replication, essentially during the viral adsorption to host cells. A bioguided purification process of the AE indicated that negatively charged polysaccharides were responsible for this antiviral activity.
Subject(s)
Antiviral Agents/pharmacology , Asteraceae/chemistry , Herpesvirus 1, Human/drug effects , Plant Extracts/pharmacology , Animals , Chlorocebus aethiops , Microbial Sensitivity Tests , Vero CellsABSTRACT
CH2Cl2 and MeOH extracts of 15 Argentine plants used locally as insecticides, were evaluated for their insecticidal activity. Chenopodium multifidum L. (Chenopodiaceae); Flaveria bidentis (L.) O.K. (Compositae); Aristolochia argentina Gris. (Aristolochiaceae) and Tagetes erecta L. (Compositae) showed a significant activity against Sitophilus oryzae.
