In vitro antiplasmodial and antimicrobial potential of Tagetes erecta roots.
BACKGROUND
Among strategies to combat malaria, the search for newer antimalarial compounds is a priority. Traditionally, Tagetes erecta Linn. (Compositae) has been used for the treatment of various diseases and ailments including malaria.


OBJECTIVE
Five successive extracts (petroleum ether, chloroform, ethyl acetate, methanol and aqueous) of the roots of T. erecta and a new bithienyl compound, 2-hydroxymethyl-non-3-ynoic acid 2-[2,2']-bithiophenyl-5-ethyl ester from the roots of the plant, were evaluated for in vitro antiplasmodial activity against chloroquine sensitive and resistant strains of Plasmodium falciparum. The extracts were also tested for in vitro antimicrobial activity against seven microbial strains.


METHODS
The antiplasmodial screening was carried out using the schizont maturation inhibition assay. Preliminary antimicrobial screening was carried out using the agar well assay followed by determination of minimum inhibitory concentration (MIC) using two-fold serial dilutions.


RESULTS
Among all the extracts tested, the ethyl acetate fraction exhibited significant antiplasmodial efficacy with the 50% inhibitory concentrations (IC(50)) of 0.02 and 0.07 mg/mL against the chloroquine sensitive and resistant strains of Plasmodium falciparum respectively. The new bithienyl compound also showed significant schizonticidal activity against both chloroquine sensitive and resistant strains of Plasmodium falciparum with the IC(50) values of 0.01 and 0.02 mg/mL. Additionally, all extracts exhibited significant antimicrobial activity against three Gram-positive and two Gram-negative bacterial and two fungal strains with MIC values ranging between 12.5-100 µg/mL.


CONCLUSIONS
The new bithienyl compound was profoundly able to arrest the ring stages of the malarial parasites thereby exerting its antiplasmodial effect.


CONCLUSIONS
The observations provide support for the ethnobotanical use of the plant.
Gupta
Pankaj
P
Department of Pharmacognosy and Phytochemistry, Guru Jambheshwar University of Science and Technology, Hisar, Haryana, India. gupta.aiims@gmail.com
Vasudeva
Neeru
N
D000890:Anti-Infective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D000962:Antimalarials / Q000494:pharmacology / Q000627:therapeutic use; D002738:Chloroquine / Q000494:pharmacology / Q000627:therapeutic use; D004351:Drug Resistance; D006090:Gram-Negative Bacteria / Q000187:drug effects; D006094:Gram-Positive Bacteria / Q000187:drug effects; D066298:In Vitro Techniques; D020128:Inhibitory Concentration 50; D008826:Microbial Sensitivity Tests; D003904:Mitosporic Fungi / Q000187:drug effects; D008517:Phytotherapy; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology* / Q000627:therapeutic use; D018517:Plant Roots / Q000737:chemistry*; D010963:Plasmodium falciparum / Q000187:drug effects; D031686:Tagetes / Q000737:chemistry*; D013876:Thiophenes / Q000494:pharmacology* / Q000627:therapeutic use
C556332:2-hydroxymethyl-non-3-ynoic acid 2-(2,2')-bithiophenyl-5-ethyl ester; D000890:Anti-Infective Agents; D000962:Antimalarials; D010936:Plant Extracts; D013876:Thiophenes; D002738:Chloroquine