209All analyses were done in triplicate.
In determination of total alkaloids, 5 g of dry veg-
etable leaf powder was weighed, carefully trans-
ferred into a beaker and 10 percent acetic acid (20 0
ml) in ethanol added. The mixture was covered and
allowed to stand for 4 hours and filtered. The filtrate
was concentrated on a hot water bath to one-quarter
of the original volume. The concentrate was allowed
to cool at room temperature and concentrated
ammonia added dropwise until precipitation was
complete. The solution was allowed to settle and the
precipitates collected by filtering using whatman
filter paper no 1. The precipitate on the filter paper
was washed with dilute ammonia and a residue
dried in a vacuum oven at 50°C and weighed. The
total alkaloids were determined gravimetrically. All
analyses were also done in triplicate.
- Results and discussion
The results of the phytochemical composition of se-
lected indigenous African vegetables are presented
in Table 1. The phytochemical components in the dry
vegetable leaf crude extracts included alkaloids,
tannins, flavonoids, saponins, carotenoids,
coumarin derivatives and glucides. Phytochemicals
have therapeutic properties such as anti-allergic,
anti-inflammatory, antihypertensive, antidiabetic,
anti-oxidant, anti-ulcer, anti-cancer activity which
are beneficial to human health (Dembinska-Kiecet
al., 2008 ; Issaet al., 2006 ). Specifically, tannins, fla-
vanoids and coumarins are known anti oxidants
which are essential in the prevention of complicated
degenerative diseases such as cancer, cardiovas-
cular, alzheimers and parkinson (Ahmadet al.,
2006; Tungjai et al., 2008).Dietary anti-oxidants prevent production of free rad-
icals by chelating reactive species produced in the
body that are responsible for causing degenerative
diseases (Adedayoet al., 2010; Adefegha and Oboh
2011; Okigbo et al., 2009). It is also known that al-
kaloids, flavanoids, tannins, reducing compound,
sterols and triterpenes have good antimicrobial
properties that are essential in the management of
diseases such as malaria, fever, diarrhea and res-
piratory tract infection (Adebayo-Tayo and Adegoke,
2 008; Kubmarawa et al., 2007).Therefore, consumption ofA. hybridus,A. cruentus,
S. aethiopicum,C. gynandraand V. unguiculata
provides a diet with health benefits. It is necessary
for policy-makers to consider indigenous African
vegetables as important resources for human nu-
trition and improved health of the population. This
emphasizes the need to sensitize the population on
benefits of a vegetable diet in disease prevention,
thus reduce morbidity.