Agriculture Reference
In-Depth Information
lactating women and overall health management. Asthma patients chew fresh leaves to relieve
wheezing. A cold maceration of the roots is also taken as a remedy for asthma. A decoction of
the roots, combined with other plant species, is taken to treat sickle-cell anemia. A maceration
of the leaves in alcohol is taken to treat bilharzia and viral hepatitis and as a general antimicro-
bial agent.
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Constituents —
The leaves contain preganane glycosides, 17β-marsdenin derivatives,
β-sitosterol, lupenyl cinnamate, lupenyl acetate, lupeol, essential oils, and saponins. The main com-
ponents of the essential oil from the leaves are linalool (19.5%), (E)-phytol (15.3%), and aromaden-
drene hydrate (9.8%). The fixed oil contains saturated (50.2%) and unsaturated (39.4%) fatty acids.
Palmitic acid accounts for 36% of the total fatty acid content; minor saturated fatty acids are stearic
acid (4.6%), behenic acid (3.7%), and arachidic acid (2.8%). The main UFA is linoleic acid (31.1%),
followed by oleic acid (7.1%) and linolenic acid (7.1%). The nutritional composition of the dry leaves
is crude protein (9.8-27.2%), lipid extract (6.1%), ash (5.8-11.6%), crude fiber (8.7-10.8%), tannin
(0.3%), and nitrogen-free extractives (44.3%). The composition of minerals per 100 g dry matter is
K 244.8-332.1 mg, Na 110-113 mg, Ca 115.4-154 mg, P 125.5-326.9 mg, Fe 7.8 mg, Zn 13.4 mg,
Pb 0.2 mg, Cu 2.3-43.5 mg, Mg 53.8 mg, Cd 0.1 mg, Co 115.9 mg, oxalate 70 mg, and ascorbic
acid 187.1 mg. The major essential amino acids are leucine, valine, phenylalanine, aspartic acid,
glutamic acid, and glycine.
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Pharmacological Studies —
Several laboratory studies have demonstrated the possible anti-
diabetic activity of
Gongronema
. Different alcoholic leaf extracts showed promising hypoglycemic
and antihyperglycemic activities in a dose-dependent way on normal and alloxan-induced or STZ-
induced diabetic rabbits.
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An ethanolic leaf extract possessed significant antilipid peroxi-
dative activities. In a small clinical trial, the blood glucose concentration of healthy humans was
determined after consumption of the leaves and showed a significant reduction in blood glucose
level. Leaf extracts also showed antioxidant, anti-inflammatory, hepatoprotective, antiplasmodial,
antiasthmatic, antisickling, antiulcer, analgesic, antipyretic, gastrointestinal relaxing, laxative, and
stomachic activities. The antimicrobial activity of essential oil and extracts of
Gongronema
has
been demonstrated on bacterial isolates from the bloodstream of patients infected with HIV.
627
The
leaf extract has also been shown to be protective against acetaminophen hepatic toxicity in Wistar
rats.
628
Toxicity —
Gongronema
is considered a nontoxic vegetable. An oral toxicity test on rats gave
an LD
50
of 1450.5 mg/kg, and an intraperitoneal injection in mice gave an LD
50
of 1678.6 mg/kg.
Agriculture —
The herb is cultivated in gardens and homestead farms in Nigeria and other
parts of West Africa. It can be propagated by seed or softwood, semihardwood, and hardwood
cuttings. Fresh seeds have a germination rate of up to 85% at 25-29°C. Cold storage for a brief
period improves seed germination. When seeds from green-yellow follicles are matured enough to
germinate, they can be stored for a longer period than seeds from yellow follicles. Softwood stem
cuttings have better shoot and root development during the wet season, whereas semihardwood and
hardwood cuttings perform better during the dry season.
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Commerce —
A relatively modest trade in
Gongronema
occurs throughout West Africa
but mainly for its use as a bitter vegetable and spice. Its importance as a dietary supplement
is based on pharmacological activities, including hypoglycemic, antioxidant, anti-inflammatory,
hepatoprotective, antiplasmodial, antiasthmatic, antisickling, antiulcer, analgesic, and antipyretic
activities.
Formulation and Dosage Forms —
Gongronema
is an ingredient in two commercial products:
Physogen Tea (for diabetes by Neimeth Pharmaceuticals) and a general bitter tonic by InterCEDD
Health Products.
Gongronema
has also been used experimentally with positive results to replace
hops as a bitter principle in brewing beer.
