Abstract
In many African cultures, vegetables form an im-
portant part of a healthy traditional diet because of
their nutritional and health benefits. Vegetables
have been reported to have many health protecting
properties, thus illustrating the relationship be-
tween nutrition and medicine which has long been
recognized in African cultures. This study evaluated
the phytochemical composition of selected indige-
nous vegetables in Uganda. The crude extracts of
diethyl ether, 96 percent ethanol and distilled water
indicated that Amaranthus hybridus L.,Amaranthus
cruentus L.,Solanum aethiopicum L., Cleome gy-
nandra L. and Vigna unguiculataL. contain alka-
loids, tannins, flavonoids, saponins, carotenoids,
coumarin derivatives and glucides phytochemicals.
Another phytochemical, steroid glycoside, was de-
tected in the distilled water extract ofA. cruentus, S.
aethiopicumand V. unguiculata. The quantitative
analysis of the total flavonoid content inA. hybridus,
A. cruentus,S. aethiopicum,C. gynandraand V. u n -
guiculatashowed 8 .7, 1 2. 0 , 15. 2 , 2 6.4 and 1 0 .6 g per
100 g dry weight, respectively, while the total alka-
loid content showed 2.7, 3. 3 , 4.0, 3 .8 and 1.7 g per
100 g dry weight, respectively. The phytochemical
composition in the respective indigenous African
vegetables justifies their therapeutic activity against
a wide range of diseases. These phytochemicals
have anti-oxidant, antihypertensive, antidiabetic and
anti-ulcer properties that can prevent a number of
diseases. With these health benefits, there is need
to emphasize a diet rich in indigenous green leafy
vegetables to promote health and prevent diseases
in the population. There is also need for further re-
search and value addition to indigenous African veg-
etables as a potential source of drugs or medicines.
- Introduction
In many African cultures, vegetables are widely con-
sumed together with starchy staple foods such as ba-
nanas, millet, sorghum, maize, cassava and sweet
potatoes. Vegetables form an important part of a tra-
ditional African diet, since they have enormous nutri-
tional and health benefits, besides adding taste and
palatability to food (Akubugwoet al., 2008 ; Rubaihayo,
1997). Consumption of vegetables is believed to play
a significant protective role against degenerative dis-
eases such as cancer, chronic cardiovascular dis-
eases and high cholesterol levels (Adefegha and
Oboh, 2011; Agudo et al., 2002).In fact, it is reported that consumption of fruits and
vegetables lowers total cholesterol (Dragstedet al.,
2006), while consumption of 400 g of fruits and veg-
etables per day is recommended by WHO/FAO for
prevention of chronic cardiovascular diseases (Ka-
nungsukkasem et all., 2009). However, consumption
of vegetables in sub-Saharan Africa still lags behind
other regions, yet it is endowed with a high diversity
of edible vegetables (Habwe and Walingo, 2008). Of
the 1 000 edible green vegetables species in sub-
Saharan Africa, Uganda has about 600 local veg-
etable species (Ssekabembe et al., 2003).A study carried out by Bukenya-Ziraba et al.(1999)
reported 38 different types of vegetables sold in dif-
ferent major markets of Kampala, Uganda. Of the
reported vegetable species, Amaranthus sp.,
Solanumsp., Capsicumsp. and Cleome gynandra
are identified as the most commonly consumed
vegetable species (Ssekabembeet al., 2003). Al-
though vegetables are consumed widely, they are
prepared differently, depending on preferences and
indigenous knowledge of the local communities.In Uganda, vegetables are prepared by steaming,
mashing or boiling with staple food to make a local
dish (Katogo), frying with edible oil and pasting with
groundnuts or sesame (Musinguzi et al., 2006). Fry-
ing is the most popular method of vegetable prepa-
ration for eating in urban centres of Uganda and has
been adopted in rural areas as well. Vegetables are
eaten as food in form of sauce, raw as snack and sal-
ads or even side dishes of the main meal (Musinguzi207