Antiplasmodial effects of the aqueous extract of phyllantus amarus schumach and thonn against plasmodium Berghei in Swiss albino mice

Abstract

Summary:Phyllantus amarus Schumach and Thonn is a medicinal plant used commonly for the treatment of malaria-related symptoms by the general public in southeastern Nigeria. The present study determines the possible antiplasmodial effects of the aqueous extract of the leaves and stem of the plant against Plasmodium berghei infection using Swiss albino mice as models. The blood schizonticidal activity of the aqueous extract in early infection and in established Plasmodium berghei infection was assessed and compared to the activities of chloroquine and sulfadoxine/pyrimethamine. The repository activity of the extract was also assessed and compared to the activity of pyrimethamine. The LD50 of the aqueous extract of the leaves and stem of the plant was also determined using albino Wistar rats. The results show that the LD50 of the aqueous extract of Phyllantus amarus Schumach and Thonn was 650 mg/kg. In early infection, the extract at doses of 108.33 mg/kg, 165 mg/kg and 325 mg/kg was found to cause a significant dose-dependent suppression of P berghei parasites (P<0.05) sulfadoxine/pyrimethamine caused a similar significant suppression of P berghei parasites (P<0.05) while chloroquine at a dose of 5 mg/kg did not cause a significant effect on P berghei parasites. Similarly, the extract was found at all doses to cause a statistically significant (P<0.05) suppression of P berghei parasites via a repository action. This effect was comparable to the effects of pyrimethamine a standard repository agent. In established infection, the extract at all doses administered, was found to significantly suppress P berghei parasites at 24 and 72-hour periods (P<0.05). Comparatively, sulfadoxine/pyrimethamine caused a similar statistical (P<0.05) suppression of the parasites of P berghei. However, the effects of sulfadoxine/pyrimethamine were more sustained over the 72-hour period. The present study therefore validates the local use of the extracts of Phyllantus amarus Schumach and Thonn as an antimalarial agent. Further studies are however recommended to identify and possibly characterize the potential antiplasmodial agents in the aqueous extract of the plant.

Phyllanthus amarus: Ethnomedicinal uses, phytochemistry and pharmacology: A review

“…In vitro the activity was lower at the concentration of 100, 50, 25 and 12.5 g/mL and compared with chloroquine (Traore et al, 2008). The aqueous extract of leaves and stem of P. amarus at doses of 108.33, 165 and 325 mg/kg in Swiss albino mice was found to cause a significant dose-dependent suppression of P. berghei parasites [p < 0.05] sulfadoxine/pyrimethamine caused a similar significant suppression of P. berghei parasites (Dapper et al, 2007). Ethanolic, methanolic and methylene chloride extracts of entire plant of P. amarus showed significant activity against the chloroquinesensitive strain of P. falciparum 3D7.…”

In vitro Anti-Plasmodial Activity of Aqueous and Ethanolic Extracts of Moringa oleifera and Phyllanthus amarus

“…However, results from in vivo studies by Ajala et al (2011) indicated that the aqueous extract of the whole plant of P. amarus was effective against P. falciparum and had a chemotherapeutic effect similar to that of chloroquine. According to Dapper et al (2007), P. amarus had significant antimalarial properties even though the effects were not sustained compared to effects of the combination of pyrimethamine and sulfadoxine. The differences in the level of anti-plasmodial activity exhibited by whole plant extracts might be due to the amount of the bioactive compounds extracted by the two different solvents.…”

Potential antimalarials from Nigerian plants: A review

“…They are: Cylicodiscus gabunensis (Okokon et al, 2006b), Uvaria chamae and Hippocratea africana (Okokon et al, 2006a), Enantia chlorantha and Cymbopogon giganteus (Agbaje and Onabanjo, 1991;Kimbi and Fagbenro-Beyioku, 1996), Cymbopogon citratus and Ocimum gratissimum (Tchoumbougnang et al, 2005), Cassia singueana (Adzu et al, 2003), Stachytarpheta cayennensis (Okokon et al, 2008), Striga hermonthica and Tapinanthus sessilifolius (Okpako and Ajaiyeoba, 2004), Tetrapleura tetraptera (Okokon et al, 2007b), Setaria megaphylla (Okokon et al, 2007c), Phyllanthus amarus (Dapper et al, 2007), Homalium letestui (Okokon et al, 2006c) and the plant formula 'Agbo-Iba' shown to protect mice against Plasmodium yoelii nigeriensis infection; the herbs used in this formula were decocted for 3 h and then administered to mice orally to evaluate the prophylactic and curative activities. Although the 'Agbo-Iba' formula was prophylactic and had no apparent significant side effects in mice, the formula had no curative activity against established infection (Nwabuisi, 2002).…”