Pakistan Journal of Nutrition 8 (10): 1631-1635, 2009
ISSN 1680-5194
© Asian Network for Scientific Information, 2009
1631
Investigation of the Effect of Solanum incanum on Postprandial Blood Glucose
Concentration of Normoglycemic Nigerians
V. Uchenna Okolie , E. Chinwe Okeke , O. Ijeoma Ehiemere and O. Pauline Ezenduka
1 2 1 1
Department of Nursing Sciences, University of Nigeria, Enugu Campu, Nigeria
1
Department of Home Science, Nutrition and Dietetics, University of Nigeria, Nsukka, Nigeria
2
Abstract: The effect of a Nigerian vegetable plant, Solanum incanum on postprandial blood glucose levels
of normoglycemic Nigerians was investigated. Proximate analysis indicated that this vegetable contained
significant amount of fiber, which is a Non-soluble Polysaccharide (NSP). The effect of the vegetable was
compared with those of other indigenous vegetables also taken by diabetic patients, Vernonia amygdalina
and Gongronema latifolium. A-50 g glucose was used for standard glucose tolerance test of each subject.
The values were used to compare other test results. The blood glucose concentration of the subjects was
determined (post absorptively) using Accu-chek active glucometer. The vegetables (50 g each) were
processed according to the methods used by the patients; squeeze-wash-drink and chew-raw. They were
administered to the different groups of subjects who also served as their own controls (n 8, Solanum; n 8,
Vernonia; n 8, Gongronema) on separate days in randomized order. Blood glucose levels were checked at
fasting (0 min) and postprandially at 30 min intervals for 2 h. Compared with other vegetables, Solanum
elicited significant reductions (p<0.05) in blood glucose levels at most postprandial time points and for Area-
under-curve (AUC) values. AUC reductions; Solanum, 18%; Vernonia, 15%; Gongronema, 13%). The
bioactive antioxidant substances that occur naturally in stems, roots and leaves of African plants may
possess insulin - like effect. The rich NSP content of Solanum incanum is also likely to be a reducing factor.
Key words: Type 2 diabetes, dietary practices, dietary fiber, nutrition education
INTRODUCTION
In recent decades, incidence of Type 2 diabetes mellitus
(Non-insulin Dependent Diabetes Mellitus {NIDDM}) has
increased to epidemic proportions in several traditional
populations. On a global scale too, its rapidly increasing
prevalence is a significant cause for concern (Lefebvre,
2005). The conventional medical approach of simply
using insulin and oral drugs to control diabetes mellitus
is inadequate, boring and lack compliance, thus, the
patient’s exposure to long term complications remains
a risk. Some wild herbs and spices have been shown to
be most effective, relatively non-toxic and have
substantial scientific documentation to attest to their
efficacy in diabetes management (Okeke, 1998). In
many developing countries, larger parts of the
population rely heavily on traditional medicinal plants to tests, performed at specific intervals (one week) to track
meet their primary health care needs and also to
manage their diabetes mellitus. This is due to their
perceived effectiveness, minimal side effects in clinical
experience and relatively low cost. Some indigenous
vegetables, namely; Solanum incanum (anara),
Vernonia amygdalina (onugbu) and Gongronema
latifolium (utazi) were identified as alternative treatments
for diabetes by diabetic patients attending University of
Nigeria Teaching Hospital (UNTH), Ituku Ozalla. These
patients believed that the bitterness of these vegetables
would neutralize high blood sugar levels. Given the
preponderance, acceptability and affordability of these
vegetables, Solanum incanum was targeted for
investigation, to ascertain and document its therapeutic
efficacy and otherwise in the treatment of NIDDM.
MATERIALS AND METHODS
Subjects and ethical approval: This study was a clinical
work comprising twenty-four subjects. Twelve men and
twelve women were divided into three groups of eight
(8). These subjects served as their own control.
Purposive sampling method was used to select only
those who satisfied the pre-determined inclusion criteria
which included individuals (men and women) who were
normoglycemic (fasting blood sugar levels within 70-
125 mg/dL or 3.9-6.9 mmol/L) after four blood glucose
glucose levels over time. The principle of randomization
was highly observed in assigning the subjects to their
experimental conditions; the ballot method was used.
The subjects were recruited after thorough explanation
of the details of the study protocol and their voluntary
consent was obtained. The University of Nigeria
Teaching Hospital (UNTH) Research Ethics Committee
approved the study.
Preparation and processing of the vegetables: Freshly
picked Solanum leaves were bought from a local market