Evaluation of erythrocyte viability, antioxidant capacity and antiplasmodial activity induced by alkaloid extract of Phyllanthus amarus

Abstract

Introduction: The production of large amounts of reactive oxygen species in severe malarial infection is due to parasite invasion to erythrocytes. Malaria resistance to medication has left malaria-endemic countries with no alternate source of medications but traditional medicine. One of such plants utilized by traditional healers is Phyllanthus amarus. Therefore, this study aims at ascertaining the antiplasmodial and cytotoxic activities of P. amarus and its specific actions on retaining erythrocyte viability and antioxidant activity. Methods: Antiplasmodial and erythrocyte viability activities were determined in vitro via parasite suppression and tetrazolium-based colorimetric assays, respectively. Antioxidant capacity was determined by measuring extract’s ability to inhibit lipid peroxidation, scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide ions, reduce iron(III) ions, and chelate iron in vitro using documented methods. Results: Alkaloid extracts of P. amarus showed great antiplasmodial activity (IC50=0.52μg/mL) and low cytotoxic activity (CC50=54.95 μg/mL). Erythrocyte viability assay showed the minimal impact of the extract on the uninfected erythrocytes but improved viability of the infected RBC in a dose dependent manner, and antioxidant activity manifested mainly in its iron chelating activity (EC50=0.34 μg/mL). Conclusion: This study suggests that the alkaloid extract of P. amarus has significant antiplasmodial and antioxidant activities. These activities promoted the repair of parasite-induced free radical damage to the erythrocyte membrane but distorted the parasites redox balance and defense mechanism, and hence survival rate as indicated by the parasite suppression associated with alkaloid extract treatment of malarial infection.

Profiling of Phyllanthus Amarus Phytochemical Constituents and Evaluation of Associated Antimalarial Activity and Antioxidant Potential in Experimental Mice

“…All phytochemicals of P. amarus are, therefore, non-toxic with LD50 >5000 mg/kg. This is also consistent with other reports from other researchers who documented the non toxicity of extracts of P. amarus in both in vivo and in vitro systems 8,26 . There was no significant (p>0.05) change in white blood cells (WBC) when comparing negative control with positive control group (Table 1).…”

“…However, suppression by the highest dose (500 mg/kg) of the alkaloid phytochemical was notable and showed no significant difference when compared with the activity of the standard drug in blood (p>0.05). The antiplasmodial activity of Phyllanthus amarus, the plant in this study, has been reported several times by previous studies 8,14,26 . Our study further confirms this activity and suggests that the antimalarial activity of the extracts resides essentially in the activity of the alkaloids.…”

Nutriphytochemical Profiling and Changes in Cardiovascular Risk Index in Malarial Infected Mice Treated with Ethanol Root Extract of Phyllanthus Amarus

“…Different parts of the plant have been reported for specific properties, and one of these properties is the antimalarial activity. Antimalarial activity of this plant have been reported in both in vivo and in vitro systems [17,18,22,23]. This antimalarial activity can be attributed to the vast array of nutrients and active biochemical compounds present in the plant [15,23,24].…”

“…Dried powdered root of Phyllanthus amarus (about 100g) was extracted with ethanol in soxhlet apparatus for 72 h. Mixture was filtered and concentrated under vacuum. The concentrated filtrate was suspended in distilled water to obtain ethanol extract [17].…”