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The use of leafy vegetables in diet is a common practice among the people of the Northern ethnic groups of Ghana. In this study, a survey was conducted in the Bunkpurugu-Yunyoo district and Kanvilli of the Tamale Metropolis of the Northern Region of Ghana, to document the indigenous leafy vegetables routinely consumed as part of their alimentary culture. The phytochemical content, proximate composition and antioxidant properties of the plants cited were assessed. Nine leafy vegetables: Amaranthus cruentus, Hibiscus sabdariffa, Corchorus olitorius, Vernonia amygdalina, Phaseolus vulgaris, Ipomoea batatas, Adansonia digitata, Moringa oleifera and Annona reticulate were inventoried. These plants contained various groups of phytochemicals and were generally rich in carbohydrates, protein and fibre, but low in fat. They contain an appreciable amount of energy and also demonstrated good antioxidant activities. These characteristics of the vegetables suggested their usefulness in the maintenance of good health, which may also explains why these groups of Ghanaians in the Northern region are regarded as being very strong and healthy.
World Journal of Advanced Research and Reviews, 2019, 03(01), 012022
World Journal of Advanced Research and Reviews
e-ISSN: 2581-9615, Cross Ref DOI: 10.30574/wjarr
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Copyright © 2019 Author(s) retain the copyright of this article. This article is published under the terms of the Creative Commons Attribution Liscense 4.0.
(RESEARCH ART I C L E )
Phytochemistry, proximate and antioxidant properties of some indigenous leafy
vegetables
Komlaga Gustav 1, * Gaveh Eli 2, Jibira Yakubu 1 and Mensah Merlin Lincoln Kwao 1
1 Faculty of Pharmacy and Pharmaceutical Sciences, Kwame Nkrumah University of Science and Technology (KNUST),
Kumasi, Ghana.
2 Faculty of Agriculture, KNUST, Kumasi, Ghana.
Publication history: Received on 20 July 2018; revised on 12 August 2019; accepted on 16 August 2019
Article DOI: https://doi.org/10.30574/wjarr.2019.3.1.0044
Abstract
The use of leafy vegetables in diet is a common practice among the people of the Northern ethnic groups of Ghana. In
this study, a survey was conducted in the Bunkpurugu-Yunyoo district and Kanvilli of the Tamale Metropolis of the
Northern Region of Ghana, to document the indigenous leafy vegetables routinely consumed as part of their
alimentary culture. The phytochemical content, proximate composition and antioxidant properties of the plants cited
were assessed. Nine leafy vegetables: Amaranthus cruentus, Hibiscus sabdariffa, Corchorus olitorius, Vernonia
amygdalina, Phaseolus vulgaris, Ipomoea batatas, Adansonia digitata, Moringa oleifera and Annona reticulate were
inventoried. These plants contained various groups of phytochemicals and were generally rich in carbohydrates,
protein and fibre, but low in fat. They contain an appreciable amount of energy and also demonstrated good
antioxidant activities. These characteristics of the vegetables suggested their usefulness in the maintenance of good
health, which may also explains why these groups of Ghanaians in the Northern region are regarded as being very
strong and healthy.
Keywords: Corchorus; Amygdalina; Moringa; Phaseolus; Adansonia
1. Introduction
Leafy vegetables (LV) are edible leaves often used as components of food [1]. They may consist of young, succulent
stems, flowers and very young fruits together with the leaves [2].
Leafy vegetables play vital roles in human nutrition; serving as valuable sources of minerals, vitamins proteins and
fibre for the majority of people. In developing countries, they are usually consumed, though, in relatively small
amounts as side dishes [3, 4]. LV contain high amounts of dietary fibre, which helps to regulate the digestive system,
manage the body’s weight and improve health [5]. Aside these benefits, they have been strongly associated with good
health and vision, reduced risks for some forms of cancer, stroke, diabetes, anaemia, gastric ulcer and also treat
haemorrhoids, gallstones, obesity and constipation [6, 7]. They contribute to the reduction of malnutrition, especially
in children, by their content of protein, vitamins, calories and minerals needed in diets [8, 9]. They also contain non-
nutrient bioactive phytochemicals that have been reported to offer protection against cardiovascular diseases and
other ailments [10]. They are, in addition, good sources of naturally occurring antioxidant compounds that inhibit or
delay the oxidation of biomolecules by inhibiting the initiation or propagation of oxidizing chain reactions [11]. They
thus protect body cells from damage caused by oxidative stress, which is linked to several chronic diseases such as
cancers, diabetes mellitus, cardiovascular diseases and several neurodegenerative disorders in humans [11].
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In Africa, leafy vegetables are increasingly being recognized as possible contributors of both micronutrients and
bioactive compounds in diets [12]. However, Ghanaian diet comprises mainly of starchy roots, fruits and cereals [13].
Thus, according to the Food and Agricultural Organization [13], the dietary supply, though meets population energy
requirement, is lower in proteins and lipids than recommended. The people from the northern part of the country
however have consumed indigenous leafy vegetables (ILV) as a major component of their diet for generations, and
this has become part of their culinary culture. This study inventoried ILV consumed in two communities in the
Northern Region of Ghana and evaluated their phytochemical constituents, antioxidant properties and proximate
composition to assess their nutritional value as well as other health benefits to the people.
2. Material and methods
2.1. Study area
The sites chosen for the survey were two communities: Bunkpurugu of the Bunkpurugu-Yunyoo District and Kanvilli
of the Tamale Municipality, both in the Northern Region of Ghana (Fig. 1). This region has a rainfall, humidity,
temperature and vegetation typical of the savannah zone.
Figure 1 District map of the Northern Region of Ghana showing the study areas: (A) Bunkpurugu-Yunyoo District and
(B) Tamale Municipality. Inset: map of Ghana. Source: adapted from Wikimedia Creative Commons.
2.2. Survey data collection
Information on the vegetables was collected using a semi-structured validated questionnaire. Informants’ consent was
initially requested by administering informed consent forms following the explanation of the purpose of the study to
the participants. The forms were filled and willingly signed or thumb-printed after which the questionnaires were
administered. A total of 40 indigenes, 20 from each community, were interviewed using the prepared questionnaire as
a guide. The respondents who were mostly farmers and residents within the communities for at least the past 10
years were interviewed. Demographic data of the respondents were first collected on their gender, age, ethnicity,
religion, level of formal education, main occupation and duration of residence within the community. Questions
related to the vegetables included respondent’s knowledge of indigenous vegetables used in preparing food in the
areas, purposes for using particular indigenous vegetables as part of their meals if any, frequency of their inclusion in
diets, the form in which they are prepared, if the vegetables are also used as ornamental plants, their seasonal
availability, whether grown or cultivated among others. Oral and informal interviews were conducted with both
closed and open-ended questions. This was followed by collection of plant samples from their respective fields.
2.3. Collection, processing and extraction of plant materials
During the field visits, samples of the plant species were collected to prepare herbarium specimens and for further
studies. The identities of the plant species were authenticated in the Departments of Horticulture, Food Science and
Pharmacognosy, all of the Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana.
Specimens with voucher numbers were deposited at the Herbarium of the Department of Herbal Medicine, KNUST.
Komlaga et al. / World Journal of Advanced Research and Reviews, 2019, 03(01), 012022
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The taxonomic validity of the plant names were checked using the plant database; www. thePlantList.org (accessed
January, 2017). The remaining samples were cleared of all extraneous materials, air-dried at room temperature for
about two weeks and milled into a coarse powder. The dried powdered plant materials were accordingly analysed as
described below.
2.4. Phytochemical screening
Plant materials were tested for the presence of the various classes of secondary metabolites using standard methods
[14, 15].
2.5. Total antioxidant capacity using phosphate molybdenum (PM) assay
The antioxidant assay was based on the reduction of molybdenum, Mo6+ to Mo5+ by the extracts and subsequent
formation of a green phosphate molybdate (Mo5+) complex in an acidic medium [16]. Ammonia molybdate (4 mM),
disodium hydrogen phosphate (28 mM) and sulphuric acid (0.6 M) were added together in a beaker to prepare the
reagent solution. Test tubes containing 1 ml each of the different concentrations of the extract (31.25 - 500 µg/ml) and
3 ml of the reagent were incubated at 95°C for 90 minutes. The process was repeated for concentrations of ascorbic
acid as a standard (3.125 -100 µg/ml). A blank solution was prepared by adding 1 ml of methanol and the prepared
reagent solution without the extract or standard. After the mixture had cooled to room temperature, the absorbance of
the solutions were determined at 695 nm using the UV- visible spectrophotometer (Shimadzu, 1201, Japan). The
experiment involving ascorbic acid was used to construct a calibration curve. The antioxidant capacity was expressed
as µg of ascorbic acid equivalent (AAEq) per g of extract.
2.6. 2, 2 Diphenyl-picryl hydrazl (DPPH) radical scavenging assay
Free radical scavenging activity was determined as described by Govindarajan et al. [17]. About 1 ml aliquot each of
the different concentrations of the extract (31.25- 500 µg/ ml) was added to a 3 ml methanol solution of DPPH (20
mg/L) in a test tube. The reaction mixture was kept at room temperature in the dark for 30 minutes. A blank
determination was done by adding 1 ml aliquot of methanol and 3 ml of DPPH solution together. The absorbance of
the residual DPPH was determined at 517 nm in UV- visible spectrophotometer (Shimadzu, 1201, Japan). Ascorbic
acid was used as the standard. Percentage DPPH inhibition was evaluated by comparing the test and blank solutions
as follows:
 

Where A is absorbance of the blank and As the absorbance of the test sample. The IC50 value (the concentration at 50%
inhibition) was determined from the curve of percentage inhibition and log concentration.
2.7. Total phenolic content
The total phenolic content of the extracts was quantified using the Prussian Blue method [18] with some modification.
Gallic acid was used as the reference substance. About 0.1 ml of the various concentrations of the extract (31.25- 500
µg ml-1) and gallic acid (3.125 -100 µg ml-1) were transferred into test tubes and diluted with 3 ml deionized water. To
each test tube 1 ml each of K3Fe (CN)6 (0.008 M) and FeCl3 (0.01 M) was added and left in the dark for 15 minutes.
About 5 ml of tragacanth was added to each test tube as a stabilizer and the absorbance of the solutions measured at
725 nm wavelength using the UV- visible spectrophotometer (Shimadzu, 1201, Japan). The concentrations of gallic
acid were used to construct a calibration curve and the total phenol content in grams was determined as Gallic Acid
Equivalent (GAEq mg/g) of the extract.
2.8. Proximate analysis
Proximate analysis of the samples was carried out according to the methods recommended by the Association of
Official Analytical Chemists [19]. The analyses covered the seven proximate factors - moisture, protein, fat, ash, crude
fibre, total carbohydrate and energy in fresh vegetables. Moisture content was determined by the oven drying method;
ash by furnace dry ashing; crude fibre by an AOAC [19] method; crude protein by the Kjeldahl procedure; crude fat by
Soxhlet extraction method and carbohydrate by calculation. Energy value of the samples were estimated in kilojoules
per kg of sample by multiplying the protein, fat and carbohydrate percentages by the factors 16.7, 37.7 and 16.7,
respectively, and then adding the results [20].
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2.8.1. Crude fat content
Five grams (5 g) of powdered plant sample was soxhlet extracted with petroleum ether into a flask previously dried at
110°C for 5 min and weighed. The extraction was carried out for about 4 hours after which the solvent was completely
evaporated on water bath. The flask was placed in a desiccator and cooled to room temperature to remove any
residual solvent. It was re-weighed and the percentage fat content of the sample calculated [19].
2.8.2. Crude fiber content
Crude fiber was estimated by acid-base digestion with 1.25% H2SO4 and 1.25% NaOH solutions [19]. The dried
defatted residue was transferred into a dried clean digestion flask. About 200 ml of 1.25% H2SO4 solution was added
and boiled for 30 min under reflux in the presence of an anti-foaming material. The boiled material was filtered and
the residue washed with several portions of hot water until there was no trace of acid. The washed residue was put
back into the flask and refluxed with 200 ml of 1.25% NaOH solution for another 30 min. The content was filtered
through a weighed Gooch crucible and thoroughly washed with hot water and then with about 15 ml of 95% ethanol.
The crucible with the content was dried at 110°C to constant weight. The material (in the crucible) was incinerated in
a muffle furnace at 550°C for 30 min when the carbonaceous matter was consumed with only ash left. It was cooled in
a desiccator and weighed. The loss in weight was recorded as crude fiber. The percentage crude fiber content was
then calculated.
% crude fiber = 

Where A = weight of dry crucible and sample
B = weight of incinerated crucible and ash
C = weight of sample
2.8.3. Crude protein content
Approximately, 2 g of powdered plant sample was weighed into a 500 ml digestion flask. This was hydrolyzed with 20
ml conc. H2SO4 containing selenium catalyst tablet and boiling chips under a fume cupboard into a clear solution. The
cooled digest was diluted with distilled ammonia-free water to 100 ml in a volumetric flask and used for the analysis.
About 10 ml of the hydrolysate was transferred into a clean Kjeldahl distillation flask and 90 ml distilled water
followed by 20 ml of the 40% NaOH were added. The mixture was distilled onto 10 ml of boric acid solution laced with
a few drops of methyl red/methylene blue indicator. About 150 ml of distillate was collected and titrated against 0.1 N
HCl until the first appearance of pink colour was observed. A reagent blank with an equal volume of distilled water
was titrated. The nitrogen content and therefore the protein content was calculated using the formulae below:
Total Nitrogen (NT) (g /kg) = 󰇛󰇜
 
Where Va = titre value of acid
Vb = titre value of blank
N = Normality of acid
Ws = weight of sample in grams
Therefore
% Crude Protein (CP) = Total Nitrogen (NT) x 6.25 (Protein factor) [19]
2.8.4. Moisture content
Approximately 5.0 g sample was weighed into a previously weighed moisture can. The sample in the can was dried in
the oven at 105°C for 3 h. It was cooled in a desiccator and weighed. It was again returned to the oven for further
drying. Drying, cooling and weighing were done repeatedly at hourly interval until constant weight was achieved. The
weight of moisture lost was calculated and expressed as a percentage of the weight of sample analysed [19]. It was
given by the expression below:
Moisture content = 
 
Wf = Fresh weight of sample
Wd = dried weight of sample
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2.8.5. Ash content
About 2 g of sample was weighed into a previously weighed porcelain crucible and heated to ash in a furnace at 550°C.
After complete combustion, the crucible was cooled in a desiccator and reweighed. The percentage ash content was
then determined as below [19]:
% Ash = 
 
Where Wi = weight of crucible with ash
Wf = weight of crucible only
Ws = weight of sample (2 g)
2.8.6. Carbohydrates content
Carbohydrate content was determined after completing the analysis for ash, crude fibre, ether extract and crude
protein. The percentage carbohydrate content was calculated adding the percentage values on dry matter basis of the
analysed contents and subtracting them from 100% crude substance on dry matter basis [19].
Calculation
% Carbohydrate = 100% - (% ash + % crude fibre + % crude fat + % protein)
3. Results
3.1. Respondents’ demographics
The survey to document leafy vegetables consumed in the Northern Region of Ghana was carried out in 2
communities: Bunkpurugu of the Bunkpurugu-Yunyoo district and Kanvilli of Tamale municipality starting from May
to July, 2016. The respondents were adults above 20 years and have been residents of the areas for more than 10
years. They were both females and males with the former constituting 62.5% of the participants. Indeed, in northern
Ghana, it is the woman's chore to cook, and they often make culinary decisions on behalf of the whole family.
3.2. Plant species cited as indigenous leafy vegetables
The results showed the wide range of indigenous leafy vegetables which could be obtained either from the wild or
cultivated farms. Nine (9) species belonging to 9 genera in 7 families were mentioned (Table 1.0; Fig. 2). The
Malvaceae was the predominant family encountered and had 3 species mentioned; all other families had just a species
each.
Table 1 Plant species use as indigenous leafy vegetables
Family
Scientific name
Local name
(Dagbani/Mamprusi)
Amaranthaceae
Amaranthus cruentus L.
Aleefu
Annonaceae
Annona reticulate L.
Dasaaluok
Asteraceae
Vernonia amygdalina Del.
Shuwaka
Convolvulaceae
Ipomoea batatas (L.) Lam
Wulijo vari
Fabaceae
Phaseolus vulgaris L.
Bangli
Malvaceae
Hibiscus sabdariffa L
Braa
Malvaceae
Corchorus olitorius L.
Ayoyo
Malvaceae
Adansonia digitata L.
Kuuka
Moringaceae
Moringa oleifera Lam
Jangbaduuk
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Figure 2 Photographs of indigenous leafy vegetables cited in the study
3.3. Phytochemical constituents of cited plants
The plant materials contained various phytoconstituents, which included tannins, flavonoids, glycosides, alkaloids,
steroidal and non-steroidal saponins (Table 2.0). All plant materials tested positive for glycosides, tannins and
flavonoids. V. amygdalina, C. olitorius and A. digitata contained all the phytoconstituents considered. All but H.
sabdariffa contain saponins. These phytoconstituents may contribute variously to the health benefits of these leafy
vegetables.
Table 2 Phytochemical constituents of the leafy vegetables
Scientific name
Tannins
Flavonoids
Reducing sugars
Saponins
Sterols
A. cruentus
+
+
+
+
+
A. reticulata
+
+
+
+
-
V. amygdalina
+
+
+
+
+
I. batatas
+
+
+
+
_
P. vulgaris
+
+
+
+
_
H. sabdariffa
+
+
+
-
-
C. olitorius
+
+
+
+
+
A. digitata
+
+
+
+
+
M. oleifera
+
+
+
+
-
Key: ‘+’ denotes presence and ‘-’ absence of constituent.
3.4. Total antioxidant assay
The total antioxidant capacity was expressed as Ascorbic acid equivalent of the sample. The value measures the
equivalence of ascorbic acid contained in 1 g of the plant extract (Table 3.0) and is assumed to be proportional to the
total antioxidant capacity of the sample. All the plants had appreciable antioxidant capacity with A. cruentus having
Komlaga et al. / World Journal of Advanced Research and Reviews, 2019, 03(01), 012022
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the highest Ascorbic acid equivalence of 129.3±27.28 µg/g and hence a high antioxidant capacity. A. digitata had the
least Ascorbic acid equivalence of 88.80±5.274 µg/g and hence a low antioxidant capacity.
The antioxidant property of these plants indicates their potential usefulness in reducing oxidative stress which
contributes to many chronic diseases such as atherosclerosis, cancer, diabetes, rheumatoid arthritis, post-ischemic
perfusion injury, myocardial infarction, cardiovascular diseases, chronic inflammation, stroke, septic shock, aging and
other degenerative diseases in humans [21].
Table 3 Ascorbic acid equivalence for the various samples
Sample
Ascorbic acid equivalence
(μg/g of extract)
A. cruentus
129.30±5.28
A. reticulata
71.95±4.37
V. amygdalina
99.47±4.19
I. batatas
98.06±3.73
P. vulgaris
97.35±1.36
H. sabdariffa
108.50±2.55
C. olitorius
103.40±5.18
A. digitata
88.80±2.27
M. oleifera
62.37±3.82
3.4.1. Radical scavenging assay using 2, 2 diphenyl-picrylhydrazl (DPPH)
The DPPH radical scavenging capacity was expressed as the IC50 value (Table 4.0), which is a measure of the amount of
the sample needed to scavenge 50% of the free radical, DPPH. All the plants showed free radical scavenging properties
with P. vulgaris having the lowest IC50 of 231.57±2.3 µg ml-1 and hence the highest free radical scavenging capacity. A.
digitata had the highest IC50 of 487.06±3.79 µg ml-1 and hence the least free radical scavenging capacity. This thus
confirms the low antioxidant capacity observed above for A. digitata. The free radical scavenging capacity contributes
to the antioxidant property of the plants. High radical scavenging capacity may indicate a better antioxidant property
of the plant.
Table 4 IC50 values of plant extracts and Ascorbic acid
Plant material
IC50 (µg/ml)
A. cruentus
408.0±3.1
A. reticulata
261.4±7.74
V. amygdalina
438.74±6.94
I. batatas
233.2±7.19
P. vulgaris
231.57±2.3
H. sabdariffa
438.06±4.65
C. olitorius
288.0±2.76
A. digitata
487.06±3.79
M. oleifera
489.00±2.82
Ascorbic acid
89.34±6.766
3.5. Total phenolic content
The total phenolic content was measured in terms of the Gallic acid equivalent of the sample expressed as the µg of
Gallic acid equivalent in 1 g of plant extract as shown below (Table 5.0). The value is an indication of the amount in µg
of the Gallic Acid Equivalent (GAEq) in 1 g of the plant extract. All the plants contained phenols and hence showed
antioxidant properties. A. digitata having the highest GAEq of 438.4±7.91 µg/g and hence a high total phenol content
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and H. sabdariffa having the least GAEq of 35.0±46.55 µg/g and hence a low total phenol content. The presence of the
phenols though may contribute to the antioxidant activity does not translate into significant antioxidant capacity.
Table 5 Gallic Acid Equivalence of samples
Sample
GAEq (μg/g of extract)
A. cruentus
131.2±1.63
A. reticulata
396.5 ± 44.03
V. amygdalina
179.4±3.10
I. batatas
287.1±0.024
P. vulgaris
227.1±23.97
H. sabdariffa
35.0±46.55
C. olitorius
247.5±7.175
A. digitata
438.4±7.91
M. oleifera
163.4±17.12
3.6. Proximate content of the cited vegetables
The samples were analysed for moisture, ash, lipid, protein, carbohydrate and energy contents (Table 6.0). Among the
3 nutrients: carbohydrate, protein and fat, carbohydrate content was the highest and fat the lowest for all samples.
The values indicates the nutritional importance of the vegetables to enhance growth, development and maintenance
of health. A. reticulata and M. oleifera had the highest fibre content. This being an important factor for digestive health
and regular bowel movements, can improve cholesterol and blood sugar levels and can assist in preventing some
diseases such as diabetes, cardiovascular disease and bowel cancer [6, 7]. These 2 vegetables would therefore be
useful for digestion and good bowel movement and maintenance of health. The moisture content ranges from 5% in A.
digitata and C. olitorius to 13% in I. batatas. Moisture is an important factor in food quality and preservation [22]. A.
reticulata has the highest total ash content of 46.71 and V. amygdalina the lowest of 4.73%. Total Ash/Minerals Ash
refers to the inorganic residue remaining after complete oxidation of organic matter in a foodstuff. The ash content is a
measure of the mineral content and other inorganic matter in food [23].
Table 6 Proximate composition of samples
Plant
Moisture (dry)
Ash
Fiber
Protein
Carbohydrate
Fat
Energy
A. cruentus
7
22.72
18.05
28
34.28
8
13416.76
A. reticulata
5.7
31.41
46.71
19.63
37.26
6
11762.63
V. amygdalina
10
4.73
18.78
30.13
51.14
4
15080.09
I. batatas
13
7.7
23.51
26.19
48.11
5
14293.10
P. vulgaris
8
11.61
22.05
31.69
47.7
1
13635.13
H. sabdariffa
11
6.25
19.09
32.03
48.69
2
14234.24
C. olitorius
5
21.15
20.77
24.69
45.16
4
13172.95
A. digitata
5
9.5
22.26
13.81
65.69
6
15538.50
M. oleifera
6
15.49
45.40
29.13
38.38
11
15421.17
Energy was measured in KJ/Kg dry matter
4. Discussion
Indigenous leafy vegetables have been a common component of the diet of the people of the northern ethnic groups of
Ghana. Various reasons were assigned for the consumption of this plant part in the communities. According to the
participants in this study, the consumption of leafy vegetables is a culinary tradition, and some foods are not eaten
without them. For example, corn flour meals such as "Tuo zaafi" is often if not always eaten with C. olitorius soup.
Aside the cultural reason, the people also take leafy vegetable diets for their nutritional, health and therapeutic
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benefits. Some people consumed them just to maintain good health. H. sabdariffa for example is said to enhance bowel
emptying, thus preventing constipation and unnecessary straining. V. amygdalina and M. oleifera may be routinely
added to meals in order to manage chronic health conditions such as diabetes and hypertensive. Indeed, previous
reports confirmed the antidiabetic and antihypertensive activities of V. amygdalina [24, 25] and M. oleifera [26, 27]. A.
digitata is habitually used in the diet to maintain good oral health or to treat mouth sores. Of course, A. digitate is
known to contain large amounts of ascorbic acid [28], which is important for good oral health [29]. A. reticulata for
indigestion and constipation. Indeed other studies confirmed some of these activities [3032]. The people cook the
leafy vegetables in the preparation of soups and stews and these processes may have serious implications for the
vitamins in the plant materials.
Due to the rapid urbanization of the northern region of Ghana, it is very necessary and important to document the
indigenous leafy vegetables used in these areas and evaluate their nutritional and health properties; this would
prevent the loss of such vital heritage with time.
The survey results demonstrated the rich flora of the Northern region of Ghana in terms of the availability of different
types of indigenous leafy vegetables, which offer varieties and broaden the food base for the people. Interestingly,
these leafy vegetables are obtained both from the wild and from cultivated farms in season. Unfortunately, some of
these vegetables are annuals and are only available for a short period (about 3 months) of the year due to the long
drought season that characterize the Northern part of Ghana. Leaves from perennial plants are not always available as
these are shed during the drought. This condition may account for the high incidence of the reported
undernourishment in that part of the country [13, 33] despite the rich dietary culture of the people.
5. Conclusion
The Northern Ghana is endowed with a rich biodiversity which include indigenous plants which serve as leafy
vegetables and form part of the diet of the people. The vegetables are rich in antioxidants, the 3 classes of nutrients:
carbohydrate, protein and fat. They also contain appreciable amounts of fibre and energy and are useful in the
maintenance of good health. The regular consumption of the indigenous leafy vegetable in the diet may explain why
these groups of Ghanaians are often regarded as very strong and healthy.
Compliance with ethical standards
Acknowledgments
We are grateful to the participants from Bunkpurugu of the Bunkpurugu-Yunyoo district and Kanvilli of Tamale
municipality, Northern Region, who freely shared their knowledge and time with us during the study. We thank Mses
Jemimah Afia Bamiyi Ntewusu and Ruby Edinam Tettey Tapang who collected the data as students on this project. We
appreciate their contribution to the success of the study.
Disclosure of conflict of interest
All authors declare no conflict of interest
Statement of informed consent
Informed consent was obtained from all individual participants included in the study.
References
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How to cite this article
Komlaga G, Gaveh E, Jibira Y and Mensah MLK. (2019). Phytochemistry, proximate and antioxidant properties of some
indigenous leafy vegetables. World Journal of Advanced Research and Reviews, 3(1), 12-22.
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Twenty-four (24) adult albino Wistar rats (twelve males and twelve females) were used for the study. The animals were divided into six groups of four rats in each. Proximate analysis was carried out on the plant sample with the following results: crude protein 22.45 ± 0.01%; crude fat (3.45 ± 0.0%); crude fiber (16.0 ± 0.0%) and Ash (9.95 ± 0.2%). Quantitative phytochemical analysis revealed the presence of flavonoids (0.85 ± 0.11 mg), tannins (0.37 ± 0.2 mg), saponins (2.2 ± 0.0 mg), polyphenol (0.35 ± 0.11 mg), alkaloids (2.13 ± 0.10 mg) and HCN (12.25 ± 0.10 mg). Some of the vitamins analyzed included: Vitamin A 345.50 ± 0.0 IU), Vitamin C (228.40 ± 0.0 mg), Vitamin E (37.30 ± 0.01 mg), Vit.B1 (1.0 ± 0.00 mg), Vit.B2 (3.10 ± 0.00 mg), Fe (11.0 ± 0.0 mg) and Niacin (0.41 ± 0.0 mg) respectively. Hyperglycemia was induced in the rats using alloxan. The plant extract of Vernonia amygdalina (bitter leaf) was administered to the rats orally at concentrations of 2%, 4%, 6%, 8% and 10% before meals for 5, 10 and 15 days respectively after which, blood samples were collected from the animals and analyzed for glucose levels using enzymatic methods. There was a remarkable decrease in blood glucose level from the mean value of 4.44 ± 0.2 to 1.66 ± 0.2 mmol/L. The decrease in the blood glucose level of the rats following the administration of the plant extract suggests that the plant extract possesses anti-diabetic, anti-hyperglycemic and hypoglycemic effects on alloxan induced diabetic rats. The presence of phytochemicals, vitamins and other nutrients such as proteins, lipids, carbohydrates, ash and other components in the extract must have acted synergistically to potentiate the anti-diabetic role of the plant extract. Keywords: Diabetes mellitus, hyperglycemia, diabetic rats, Vernonia amygdalina.