The contribution of phytochemicals to the antisickling activity of any medicinal plant used in the management of SCD is not in doubt, as many reports have attributed the antisickling properties of such plants to their innate phytochemicals. For instance, zanthoxylol
, a butyric acid derivative and 1-hydroxylbenzoic acid, which were isolated from Fagara zanthoxyloides Lam
) have been suggested to be responsible for the antisickling activity of this plant.[18
] Moringa oleifera
has been reported to contain a rich store of elements like zinc, which possesses antisickling activity, as well as organic acids. Drumstick leaves are also rich sources of flavonols, such as, kaempferol and 3’-OMe quercetin. A flavone, acacetin, and a glycoflavone 4-OMe Vitexin were also detected. Phenolic acids that have been identified, include melilotic acid, p
-coumaric acid, and vanillic acid,[22
] which could be responsible for the exhibited antisickling activities.
Phytochemical examination of the herbal formula extract, Ajawaron (used for SCD management in Nigeria) whose main constituent is the root of Cissus populnea
Guill and Perr. (Vitaceae) was found to contain anthraquinones, steroidal and cardiac glycosides, while alkaloids and tannins were absent.[19
] This study consequently lends credence to the earlier affirmed position considering the phytochemical compositions of the investigated plant parts vis a viz their corresponding exhibited antisickling activity.
Both the seed and flower fractions of Moringa oleifera
exhibited a significantly higher antisickling activity, when compared with the leaf extract. This could be attributed to the fact that the latter had only saponins, while the former duo had anthraquinones and alkaloids in addition to saponins. The fact that both butanol and ethylacetate fractions of MO leaf could cause lysis of erythrocytes depending on the concentration used, is an important factor that will caution against the inclusion of MO leaf in the recipes for SCD treatment. It has been reported that the mode of preparation of traditional recipes, as stipulated by the herb seller, was by decoction with clean water.[17
] The observed significantly higher (P
<0.05) antisickling activity of aqueous extract in this study, supports this, and it is believed that oxidative damage to cells is responsible for the activation of KCl-co-transport in sickled erythrocytes.[23
] The sickled cell erythrocytes being fragile and dehydrated require that minerals and antioxidants be constantly supplied to maintain hydration of the cells and membrane integrity.
Consequently, the contribution of micronutrients and the antioxidative properties of some plants, to their antisickling properties have been investigated. Such plants include, aged garlic,[24
] Mormodica charantia
] and Cymbrogon citratus
] Incidentally, the antioxidative properties of Moringa oleifera
had been reported in literature.[27
] It then becomes probable that the observed antisickling properties of Moringa oleifera
seed and flower fractions in this study could possibly be due to its innate antioxidants and phytochemicals.
In this study, the crude methanol extract of Moringa
leaf had an insignificant (P
>0.05) antisickling activity. Paradoxically, its activity in reversing the sickled cell was highly significant (P
<0.05). Four cations (K+
, and Mg2+
) have reportedly come into prominence in modulating the ionic pathways involved in the dehydration process.[29
] Additionally, it was reported that the ensuing electrolyte imbalances are triggered by diffusional and osmolytical activities. Previous reports have evaluated the mineral contents of Moringa oleifera leaves.[30
] On understanding that cations such as K+
, and Mg2+
(which are implicated in the process of sickling) may be important parameters in sickle cell management;[32
] the involvement of some of these cationic contents of Moringa leaf in the modulation of the ionic pathways of the sickled SS erythrocytes, being responsible for the reversal of sickling observed in the present study is plausible. However, this should be further investigated.
] in his study asserted that Moringa oleifera
is native to the Sub-Himalaya tracts of India, Pakistan, Bangladesh and Afghanistan but the fact that Nigeria carries 25% of the 89% SCD sufferers in Africa,[12
] could be the reason that the plant is being lately propagated in Nigeria. None of the traditional recipes that are used in SCD management in Nigeria contained Moringa oleifera
as a constituent to the best of our knowledge. Therefore, this study which is the first to test the antisickling effects of a common edible plant in Sub-Saharan Africa where sickle cell disease is most prevalent presents a platform to explore the use of Moringa oleifera
for the management of sickle cell disease patients.