Evaluation of the antimalarial properties and standardization of tablets of Azadirachta indica (Meliaceae) in mice

Abstract

The antimalarial activities of the tablet suspension of the bark and leaf of Azadirachta indica were evaluated on Plasmodium yoelli nigeriensis infected mice. The tablet suspensions exhibited high prophylactic, mode-rate suppressive and a very minimal curative schizonticidal effect. No animal was cured of the infection in the curative test and there was not much increase in the survival time of the animals compared with the control. The tablet suspensions from the leaf and bark at a concentration of 800 mg/kg and chloroquine at a concentration of 62.5 mg/kg body weight produced average percentage (%) parasitaemia of 79.6%, 68.2% and 99.5% for leaf, bark and chloroquine, respectively, in chemosuppression. Also in the prophylactic treatment, the tablet suspensions at 800 mg/kg and pyrimethamine at a concentration of 0.35 mg/kg gave an average parasitaemia reduction of 75.3%, 65.6% and 98.3% for the leaf, bark and pyrimethamine, respectively. There was a clear indication that both tablet suspensions from the leaf and bark possess antimalarial activity and a suspension from the former is relatively more effective than the bark. Extrapolation of the results from the antimalarial activity of the tablet suspension of the crude plant parts showed that an adult human would need to ingest a minimum of 48 g of the powdered plant material per day, an amount that is impracticable. A survival index value of 0.33 was obtained with the 800 mg/kg dose level, indicating that the tablet suspension has some moderate beneficial effect.

Screening of selected indigenous plants of Cambodia for antiplasmodial activity

“…Among the species displaying an antiplasmodial activity, Azadirachta indica (Meliaceae) (Dhar et al, 1998; El Tahir et al, 1999;Isah et al, 2003), Bixa orellana (Bixaceae) (Deharo et al, 2001), Brucea javanica (Simaroubaceae) (Murnigsih et al, 2005), Eurycoma longifolia (Simaroubaceae) (Chan et al, 2004) have been already reported for their antimalarial activity. Although the samples collected in Cambodia may differ from samples from other locations.…”

Potential antimalarials from Nigerian plants: A review

“…Twelve Nigerian medicinal plants have been reported to exhibit activities in vitro and in vivo include Azadirachta indica MacKinnon et al, 1997;Isah et al, 2003), Morinda lucida , Khaya grandifoliola Bickii et al, 2000), Quassia amara (Ajaiyeoba et al, 1999;Bertani et al, 2005), Guiera senegalensis (Iwalewa et al, 1990;Ancolio et al, 2002), Tithonia diversifolia (Goffin et al, 2002;Elufioye and Agbedahunsi, 2004), Vernonia amygdalina (Masaba, 2000;Abosi and Raseroka, 2003), Cassia occidentalis (Iwalewa et al, 1990;Tona et al, 1999;Zirihi et al, 2005), Crossopteryx febrifuga Elufioye and Agbedahunsi, 2004), Spathodea campanulata (Makinde et al, 1988;Dhanabalan et al, 2008), Momordica balsamina (Benoit-Vical et al, 2006) and Picralima nitida (Okokon et al, 2007a;Iwu and Klayman, 1992). Azadirachta indica antimalarial activity is attributed to a substantial oxidative stress during malaria infection; it affects all stages of maturation of the gametocytes, unlike artemisinin and primaquine that seem to affect only the immature stages (Dhar et al, 1998).…”

“…It is an evergreen, fast growing tree, up to 25 m in height and is used in traditional medical practice in form of an aqueous decoction of the leaves, stem bark and root . Due to the importance of this plant as an antimalarial remedy in Nigeria, efforts were made to produce the tablet suspensions of the bark and leaf which exhibited high prophylactic, moderate suppressive and a very minimal curative schizonticidal effect in mouse model of malaria (Isah et al, 2003). Khaya senegalensis and Khaya grandifoliola are often planted by roadsides for shade.…”

Plants as antimalarial agents in Sub-Saharan Africa

“…Notable among these were fruits of Allium cepa L., unripe fruits of A gedunin-rich extract of A. indica was safe and registered in Nigeria as 250mg capsules of IRACARP®; adult treatment cost around US $6.00 (Wells, 2011). However, Isah et al (2003) found that although A. indica tablet suspensions exhibited high prophylactic, mode-rate suppressive and very minimal curative schizonticidal effects, no animal was cured of Plasmodium yoelli nigeriensis infection and there was no significant increase in the survival time of the animals compared with the control. They extrapolated that an adult human needed to ingest a minimum of 48 grams of powdered A. indica per day, an amount that was not practicable.…”