Sustainable diets and biodiversity

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Apart from preventing diseases, vegetables can be a

source of drugs for treatment. Several drugs have

been developed from plant extract. An alkaloid (qui-

nine) and a sesquiterpene (artemesinin) that is used

in the treatment of complicated malaria have been

developed from the bark of Cichona tree and

Artemisia annuaplants, respectively. This therefore

means that vegetables can also be a potential source of

phytochemicals that can be developed into drugs for

prevention or treatment of diseases (Table2). There is

also need to understand the chemical compounds in

indigenous African vegetables that can be scientifi-

cally investigated and developed into potential drugs.

Further research is needed to isolate and determine

specific chemical compounds in the identified alka-

loids and flavanoids that can be developed into drugs.

Table 1 .Phytochemical composition of selected African edible vegetables.

Species of vegetable

A. hybridus A. cruentus S. aethiopicum C. gynandra V. unguiculata

Diethyl ether extract

Sterols and triterpenes (–) (–) (–) (–) (–)

Carotenoids (+) (+) (+) (+) (+)

Basic alkaloids (+) (+) (+) (+) (+)

Flavanoid aglycones (+) (+) (+) (+) (+)

Emodols (+) (–) (–) (–) (–)

Coumarins (–) (–) (+) (+) (+)

96% ethanol extract

Ta n nins (+) (+) (+) (+) (+)

Reducing compounds (–) (–) (–) (–) (–)

Alkaloids (+) (+) (+) (+) (+)

Coumarin derivatives (+) (+) (+) (+) (+)

Anthracenosides (–) (–) (–) (–) (–)

Steroid glycosides (–) (+) (+) (–) (+)

Flavonosides (+) (+) (+) (+) (+)

Saponins (+) (+) (+) (+) (+)

Water extract

Polyuronides (–) (–) (–) (–) (–)

Reducing compounds (–) (–) (–) (–) (–)

Glucides (+) (+) (+) (+) (+)

Starch (–) (–) (–) (–) (–)

Saponins (+) (+) (+) (+) (+)

Tannins (+) (+) (+) (+) (+)

Alkaloid salts (–) (–) (–) (–) (–)

Key: (+) present or detected (–) not present or not detected