Relative bioavailability of folate from the traditional food plant Moringa oleifera L. as evaluated in a rat model

Moringa oleifera is an affordable and rich source of
dietary folate. Quantification of folate by HPLC showed that
5-formyl-5,6,7,8-tetrahydrofolic acid (502.1 μg/100 g DW)
and 5,6,7,8-tetrahydrofolic acid (223.9 μg/100 g DW) as the
most dominant forms of folate in M. oleifera leaves. The bioavailability
of folate and the effects of folate depletion and
repletion on biochemical and molecular markers of folate status
were investigated in Wistar rats. Folate deficiency was
induced by keeping the animals on a folate deficient diet with
1 % succinyl sulfathiazole (w/w). After the depletion period,
animals were repleted with different levels of folic acid and
M. oleifera leaves as a source of folate. Feeding the animals
on a folate deficient diet for 7 weeks caused a significant
(3.4-fold) decrease in serum folate content, compared to
non-depleted control animals. Relative bioavailability of folate
from dehydrated leaves of M. oleifera was 81.9 %. During
folate depletion and repletion, no significant changes in liver
glycine N-methyl transferase and 5-methyltetrahydrofolatehomocysteine
methyltransferase expression were recorded.
In RDA calculations, only 50 % of natural folate is assumed
to be bioavailable. Therefore, the bioavailability of folate from
Moringa is much higher, suggesting that M. oleifera based
food can be used as a significant source of folate.