Antioxidant Potential and Cytogenotoxicity Activity of Methanol Extract of <i>Asystasia vogeliana</i> Benth Leaf

Abstract

In Nigeria, Asystasia vogeliana leaf is used for treatment and management of many human illnesses. The research explored the  antioxidant, cytotoxicity and genotoxicity effects of Asystasia vogeliana leaf methanol extract (AVLME), in order to establish its anti- malignant potential. Fine powder of the air-dried plant leaves was produced by pulverization. It was extracted using methanol. The  filtrate was concentrated to dryness on a rotavap at 40ºC. Antioxidant activity was assessed using Ferric reducing antioxidant potential  (FRAP), 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and metal chelating assay. Brine Shrimp lethality and Allium cepa L. assays were used to investigate the cytotoxicity and genotoxicity activities. The results revealed that the IC50 for FRAP, DPPH and metal chelating assays were  129.13 µg/mL, 0.43 mg/mL and 2.17 mg/mL, respectively. Nauplii of Brine shrimp responded to the extract treatment with high lethality  in the Brine shrimp assay. Mortality was highest at 0.1 mg/mL concentration of the extract. Lethal Concentration 50 (LC₅₀) of the extract  for the Brine Shrimp mortality was evaluated to be 62 µg/mL. Analysis of variance revealed that the mitotic index mean of A. Cepa treated  with various concentrations of AVLME was significantly difference (P < 0.05). The reduction in the mitotic index along with  disrupted and degenerated cells showed that the extract has cytotoxicity potential. Chromosome aberration observed in the cells of  Allium cepa root indicates genotoxicity activity of the extract. Hence, the study shows that the AVLME possesses antioxidant potential and  exhibits genotoxicity and cytotoxicity effects toward A. cepa root tip cells and Brine shrimp nauplii.