Herbal Drug For Diabetes.

Researchers have enlisted another local
plant as potent weapon in the fight
against diabetes and degenerative
diseases.
NIGERIAN and United Kingdom researchers
have discovered a promising plant for the
management of diabetes of anti-diabetic
drugs. Besides, the plant, according to
Nigerian researchers, could serve as sources
of antioxidants and bioactive compounds
for therapeutic purposes.
Commonly called ginger lily, or bush-cane,
Costus afer belongs to the plant family
Costaceae. In Nigeria, it is ukhueruoha in
Edo, mbritem in Efik, kakii-zuwaa in Hausa,
mbiritem in Ibibio, okpete, okpoto or okpete
ohia in Ibo, andura in Jukun, achikku in Tiv
and atare tete-egun in Yoruba.
Previous studies have shown that the
succulent stem is chewed as a remedy for
cough. The root decoction is administered
for the treatment of sleeping sickness and
stomachache. It is also used in the treatment
of diabetes mellitus in folklore medicine.
Researchers at the School of Biological
Sciences, University of Reading, United
Kingdo; and Faculty of Natural Sciences, Kogi
State University, Anyigba in a recent work
validated the use of Costus afer as a
hypoglycaemic (reduces blood glucose/
sugar) plant in native medicine.
According to the study published in British
Journal of Pharmaceutical Research, the
plant extract did not reduce blood glucose
in fed rats, but significantly reduced blood
glucose when administered in combination
with a conventional anti-diabetes drug,
glibenclamide.
The researchers said that these effects
could be attributed to its phytochemical
constituents.
The study is titled “Evaluation of the
Phytochemical Composition and
Hypoglycaemic Activity of Methanolic
Leaves Extract of Costus afer in Albino Rats.”
Another study published in African Journal
of Biotechnology found that methanol and
aqueous extracts of Costus afer possess
anti-oxidative properties as well as
bioactive metabolites. “Thus, stem extracts
of Costus afer could serve as sources of
antioxidants and bioactive compounds for
nutrition and therapeutic purposes. ”
The study is titled “Phytochemical
constituents and antioxidant activities of
aqueous and methanol stem extracts of
Costus afer. ”
The results of the study by the researchers
from Babcock University, School of Science
and Technology, Department of Chemical
and Environmental Sciences, Ikeja, Lagos
and Redeemer ’s University, Department of
Biological Sciences, Lagos-Ibadan
Expressway, Mowe, Ogun State, showed
that aqueous extract of Costus afer with
high phenolic content showed higher
antioxidant and inhibition of lipid
peroxidative activity than methanol extract.
They concluded: “These suggest its
potential in the treatment and prevention of
various oxidative related diseases.
Therefore, stem extract of Costus afer could
be exploited as sources of free radical
scavengers and bioactive metabolites for
nutritional, medicinal and commercial
purposes.”
The researchers of the Costus afer/diabetes
study wrote: “Oral administration of the
methanolic leaf extract of Costus afer
showed a dose dependent hypoglycemic
effect as revealed. Doses of 200 mg/kg and
800 mg/kg produced significant
hyoglycemic effect in fasted normal rats by
34.22 per cent and 59.21 per cent. Oral
administration of five-mg/kg glibenclamide
(GB) also caused significant reduction in
fasting blood glucose comparable with 200-
mg/kg leaf extract (LE) but much less than
800mg/kg LE.
“Contrary to this is a rapid increase in
fasting blood glucose experienced when
glucose was co-administered with the LE.
Studies for complementarities of LE and GB
displayed positive results. Co-administration
of 400mg/kg LE and 2.5 mg/kg GB caused a
56.58 per cent and 36.84 per cent reduction
in fasting blood sugar over six hours in the
absence and presence of oral glucose
feeding respectively.
“From phytochemical analysis, it was found
that the major constituents of the extract
were terpenoids, flavonoids, phenols,
alkaloids, glycosides and tannins. Over 150
plants extracts and some of their active
principles including flavonoids are known
to be used for the treatment of diabetes.
Moreover, tannin-containing drug
demonstrated anti-diabetic activity.
Similarly, several phenolic compounds and
flavonoid possess marked anti-diabetic
activity. Possibly the insulin-like activity of
these bioactive compounds inherent in
Costus afer is responsible for its
hypoglycaemic effects.
“The bioactive agents possibly mobilised
glucose to their store while decreasing the
blood glucose level. On the contrary,
methanolic leaf extract of Costus afer
caused a rapid increase of blood glucose
level. While the explanation may be
farfetched, it could be reasoned that may be
glucose and the bioactives in the plant
material are competing for same binding
sites thereby inhibiting glucose uptake from
the blood. Positive results from the
experiments utilising both glibenclamide
and the plant extract points at the
possibility of using both in complementary
treatment of diabetes mellitus without fear
of drug-drug interaction. ”
The researchers of the Costus afer/
antioxidant study added: “Alkaloids are
known to have anti-microbial, antifungal
and anti-inflammatory effect and it also acts
as an anti-hypertensive agent. The folkloric
use of Costus afer in the treatment of sore
throat, diarrhoea, heamorrhage and wound
healing might be due to presence of
tannins. Cardiac glycosides and
anthraquinone tested positive in methanol
and aqueous extracts. Cardiac glycosides
had been reported to be effective in the
treatment of congestive heart failure and
regulation of heartbeat.
“Anthraquinones can induce laxative effect,
hence the use of Costus afer as laxative and
nervous system depressant may result from
the presence of anthraquinones. Flavonoids
and phenols were abundant in aqueous
extract than methanol extract. These are
potent water-soluble antioxidants, which
prevent oxidative cell damage suggesting
antiseptics, anticancer, anti-inflammatory
effects and mild anti-hypertensive
properties.
“Furthermore, plant phenolics are major
group of compounds acting as primary
antioxidants or free radical scavengers. The
therapeutic potential of antioxidants in
controlling degenerative diseases with
marked oxidative damage from reactive
oxygen species or free radicals have been
reported.”