Mechanism of antimalarial action and mitigation of infection-mediated mitochondrial dysfunction by phyto-constituents of Andrographis paniculata ((Burm f.) Wall. ex Nees) in Plasmodium berghei-infected mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Andrographis paniculata (AP) ((Burm f.) Wall. ex Nees) is a medicinal plant, documented for its folkloric use in the treatment of malaria.

AIM: This study was designed to determine the potency of extract and fractions of A. paniculata (AP) as a curative, both for susceptible and resistant malaria and to also determine the plant's mechanism of action. This study was also designed to determine whether AP extract and its most potent fraction will mitigate infection-mediated mitochondrial dysfunction, and to assess the phytochemical constituents of the most potent fraction.

MATERIALS AND

METHODS

n-Hexane, dichloromethane, ethylacetate and methanol were used to partition the methanol extract of A. paniculata. Graded doses of these extract and fractions were used to treat mice infected with chloroquine-sensitive strain of P. berghei in a curative model. The most potent fraction was used to treat mice infected with resistant (ANKA strain) P. berghei. Inhibition of hemozoin formation, reversal of mitochondrial dysfunction and antiinflammatory potentials were determined. A combination of ultraperformance liquid chromatography-quadrupole time of flight-mass spectrometry and nuclear magnetic resonance spectroscopy were used for chemical analysis.

RESULTS

Microscopy revealed that the dichloromethane fraction decreased the parasite burden the most, and inhibition of the hemozoin formation is one of its mechanisms of action. The dichloromethane fraction reversed parasite-induced mitochondrial pore opening in the host, enzyme-dependent ATP hydrolysis and peroxidation of host mitochondrial membrane phospholipids as well as its antiinflammatory potentials. The UPLC-qTOF-MS report and NMR fingerprints of the dichloromethane fraction of A. paniculata yielded fourteen compounds of which sibiricinone C was identified from the plant for the first time.

CONCLUSION

Fractions of A. paniculata possess antiplasmodial effects with the dichloromethane fraction having the highest potency. The potent effect of this fraction may be attributed to the phytochemicals present because it contains terpenes implicated with antimalarial and antiinflammatory activities.