PLANT SCIENCE TODAY
ISSN 2348-1900 (online)
Vol 9(2): 477–485
https://doi.org/10.14719/pst.1476
HORIZON
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RESEARCH ARTICLE
Authentication and quality control of Uapaca heudelotii Baill. An investigation of pharmacognostic, phytochemical and physicochemical properties of its leaves and stem bark
Evelyn Asante-Kwatia*, Lord Gyimah , Abraham Yeboah Mensah , Kwame Sarpong & Ama Kusiwah Obeng
Department of Pharmacognosy, Faculty of Pharmacy and Pharmaceutical Sciences, College of Health Sciences, Kwame Nkrumah University of Science
and Technology, Kumasi, Ghana
*Email: emireku@yahoo.com
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ARTICLE HISTORY
Received: 09 September 2021
Accepted: 29 December 2021
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CITE THIS ARTICLE
Kwatia E A, Gyimah L, Mensah A Y , Sarpong K,
Obeng A K. Authentication and quality control
of Uapaca heudelotii Baill. - An investigation
of pharmacognostic, phytochemical and
physicochemical properties of its leaves and
stem bark. Plant Science Today 9(2): 477–485.
https://doi.org/10.14719/pst.1476
Abstract
Uapaca heudelotii Baill. is well known in various African cultures for its application in the treatment of infections and inflammatory conditions. This
study was focused on providing standard identification parameters for authentication and quality assurance of U. heudelotii through morphological
observations, screening of phytochemical constituents, fluorescence, spectroscopic and physicochemical analysis. U. heudelotii leaves are simple, elliptic and arranged in whorls. The bark is greyish-brown with longitudinal
striations on the outer surface and pale red on the inner surface. Leaf lamina microscopy displayed anticlinal polygonal straight-walled epidermal
cells, with anisocytic stomata found only on the abaxial surface. Leaf surface constants were determined. Microscopy of powdered leaves and barks
revealed the presence of epidermal cells, starch grains, calcium oxalate,
sclereids and pitted vessels. Alkaloids, flavonoids, coumarins, saponins,
triterpenoids, phytosterols and tannins were identified in both stem bark
and leaves. The total phenolic content for the leaf and bark were 219.2 ±
10.013 and 153.9 ± 1.602 mg/g gallic acid equivalent respectively. The total
flavonoid contents were recorded as 1036 ± 33.37 and 310.2 ± 79.00 mg/g
quercetin equivalent for the leaf and bark respectively. The total ash for the
leaf and bark was 6.41 ± 0.208 and 5.01 ± 0.258 respectively. The pH values
for the aqueous and alcoholic extracts were slightly acidic (3-5). In elemental analysis, lead (Pb) was detected within the acceptable limit (0.00190.0025 mg/kg). In conclusion, the current results have provided standard
parameters for the correct identification and quality assessment of U. heudelotii.
Keywords
Uapaca heudelotii, macro-morphology, micro-morphology, fluorescence, mineral
content
Introduction
Phytotherapy has for the past decades seen an increased usage and wide
acceptability in both developing and industrialized countries due its effectiveness and safety. This upsurge in the practice and commercialization of
herbal drugs is however faced with the challenge of misidentification of closely related species and adulteration of crude materials for financial gains (1). In
facing this challenge, it is fundamental that conditions to ensure correct identification and quality of samples be laid down (2). Establishing standards for
proper identification, quality and safety assurance through pharmacognostic,
phytochemical and physicochemical studies is thus very vital (3).
Plant Science Today, ISSN 2348-1900 (online)
478 KWATIA ET AL
Plant description, habit and distribution
The genus Uapaca (Euphorbiaceae) consists of about 50
species with strikingly similar morphological features distributed across most of tropical Africa and Madagascar (4,
5). Uapaca heudelotii, commonly called the “sugar plum”,
is a well-known species recognized for its medicinal uses in
traditional medicine. It is an evergreen dioecious small to
medium-sized tree with a condensed low-branching crown
which bears sweet edible fruits (4, 6). The plant is usually
found growing at river banks in riverine forests.
Ethnomedicinal uses
In folk medicine, decoctions of the stem bark are used to
treat cough and cold (4, 7), fever (4, 7), headaches (4, 7),
tooth-ache (7), gastrointestinal infections (7), female infertility (7), skin infections (4, 7), rheumatism (4, 7) and as
enema for constipation or haemorroids (4, 6, 7). The leaves
are pulped with palm-oil for external application to furuncles and to relieve migraines (7). The plant is locally called
“kuntan” by the Akans in Ghana and is highly commercialized as a massage to aid toddlers late in walking (7).
Biological activity and phytochemistry
In a previous study, extracts from U. heudelotii demonstrated potent anti-sickling and antibacterial activity attributed to anthocyanins and organic acids (8). Various
solvent fractions and flavonoid glycosides from the stem
bark also showed broad spectrum antibacterial activity as
well as antioxidant effect (9-11).
Pharmacognostic studies
The misapplication of herbs or natural products usually
begins with wrong identification of species which look similar to the naked eye. Such challenges can be resolved by
pharmacognostic studies. Pharmacognostic studies deal
with the study of the morphological, phytochemical and
physicochemical properties of a plant drug. Unlike taxonomic identification, a pharmacognostic study includes
parameters which help in identifying adulteration in dry
powder form also. In spite of the medicinal importance of
U. heudelotti, a search in literature reveals no data on
standard parameters for its quality control. Previous studies focused on investigating the foliar morphology of some
Uapaca species for taxonomical purposes (5, 12). In this
study, the pharmacognostic and physicochemical characteristics, elemental content, phytochemical, spectroscopic
and fluorescence patterns of the stem bark and leaves of
U. heudelotii were evaluated.
Materials and Methods
Chemicals and reagents
All chemicals and reference drugs (chloral hydrate, glycerine, phloroglucinol, hydrochloric acid, iodine solution, ethanol, chloroform, petroleum ether, ethyl acetate, aluminium chloride and Folin Ciocalteu reagent, ammonia (NH3),
sulphuric acid (H2SO4), hydrochloric acid (HCl), ferric chloride (FeCl3) and potassium hydroxide (KOH) were obtained
from Sigma-Aldrich Co Ltd Irvine, UK. All organic solvents
[ethanol (EtOH), petroleum ether (pet-ether), ethyl acetate
(EtOAc), chloroform (CH3Cl) and methanol (MeOH)] were of
analytical grade and obtained from BDH, Laboratory Supplies (Merck Ltd, Lutterworth, UK).
Harvesting and processing of plant material
Fresh disease-free stem barks and leaves of U. heudelotii
were collected near the Asuobone River in the Afram plains
district of the Eastern Region of Ghana in October,
2019.The identity of the sample was confirmed by Dr
George Henry Sam of the Herbal Medicine Department,
KNUST. Herbarium specimens, KNUST/HM1/2020/L003
and KNUST/HM1/2020/SB004 were placed at the herbarium of the Faculty of Pharmacy and Pharmaceutical Sciences, KNUST.
The plant materials were cleaned to remove all foreign materials. Fresh samples were observed for gross
morphological features. For microscopy, thin sections of
the fresh leaf midrib, petiole and lamina were obtained
using a sharp blade. The sections were cleared of all green
pigments by boiling in 80% chloral hydrate for about 4 hr
and stored in glycerine until investigation. About 200 g of
the stem bark and leaves were cleaned, air dried at room
temperature for two weeks and pulverized to obtain dried
coarse powder. The powdered materials were stored in air
tight containers at room temperature.
Macroscopic and organoleptic evaluation
For organoleptic evaluation, the taste, colour, odour and
texture of whole and powdered samples were determined.
The type of leaf, arrangement pattern, petiole and surface
characteristics of the lamina such as shape of leaf, apex,
venation, base and margin were recorded. Thirty (30) fresh
leaves were selected randomly and measured for their
average length and width. Pieces of the fresh stem bark
were observed for peculiar characteristics on the inner and
outer stem bark, fracture and curvature types (13).
Microscopic evaluation
The various microscopic studies were carried out using the
Leica DM 750 microscope (Jos Hansen and Soehn Gmbh,
Hamburg, Germany), employing a stage micrometre and a
camera lucida. The fresh transverse sections of the midrib,
petiole and the cleared sections of the leaf lamina were
observed under the microscope mounted either in a solution of glycerine or stained with phloroglucinol (0.1%w/v)
with drop of concentrated hydrochloric acid. Cell types
including epidermal cells, stomata, venation etc. were observed. Photomicrographs at x10 and x40 magnifications
were taken (14).
Subsequently, quantitative leaf surface data including the stomatal index, palisade ratio, veinlet termination
and vein islet numbers were determined using three (5)
different samples of cleared leaf lamina. The number of
the cell types per square millimetre (mm²) of epidermis
was noted. Determinations were made from five fields of
view for each sample and the results expressed as the
mean ± standard deviation (SD) (15). The stomatal index
remains constant regardless of age of plant and is usually
used for authentication purposes. SI was calculated by the
equation:
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479
where, S and E are the number of stomata and epidermal
cells respectively in microscopic view field.
Physicochemical parameters
The total, water-soluble and acid-insoluble ashes were determined. The pH of 1% aqueous and ethanolic extracts
was also determined. The mineral content and extractive
values (determined using cold maceration with ethanol,
water, petroleum ether and ethyl acetate) were determined
for the stem bark and leaves according to previously established methods (16, 17).
Phytochemical screening
Preliminary phytochemical screening were carried out to
identify the presence of the major classes of secondary metabolites in the plant samples (13). The total flavonoid and
total phenolic contents were determined using the aluminium chloride colorimetric and Folin Ciocalteu methods respectively (18, 19). Five samples each of the stem bark and
leaves were used for this assay and the results calculated as
the mean ± SD.
Fluorescence analysis
A small quantity of the powdered plant sample was mixed
with a few millilitres of solvent (water, 95% ethanol, ethyl
acetate, chloroform, petroleum ether) or reagent (conc.
NH3, conc H2SO4 conc, HCl, FeCl3, alcoholic KOH, iodine solution or NH3 solution). The fluorescence colours displayed
by the mixtures were observed under long and short wave
UV lights as well as in day light and noted (20).
Elemental Content Analysis
Fig. 1. Leaf and stem bark of U. heudelotii [A- leaf whorl, B- upper and lower
surfaces of leaf, C- inner bark, D- outer bark].
The presence and quantities of selected minerals and metals in the leaf and stem bark of U. heudelotii was assessed
cracks. It was pale-red on the inside and exuded a reddish
by the Energy Dispersive X-ray Fluorescence (17).
sap when bruised (Fig. 1. CD). The stem bark broke with a
Ultraviolet (UV-Vis) and Infrared (IR) Spectrometry
short or fibrous fracture. Powdered stem bark felt rough,
At a wavelength range of 200-800 nm and a scan speed of had a characteristic odour and bitter taste. Table 1 sum50 nm/s (PerkinElmer UV spectrophotometer), characteris- marizes the organoleptic and macroscopic characteristics
tic UV fingerprints were developed for the methanol stem of the stem bark and leaf.
bark and leaf extracts. Their IR spectra were also obtained Table 1. Organoleptic and macroscopic features of the leaf and stem bark of
from a PerkinElmer (model 1600) Fourier Transform-IR U. heuldelottii
spectrophotometer.
Results
Organoleptic and Macroscopic description
U. heudelotii is a small to medium-sized tree with a dense
low-branching crown. It bears simple leaves arranged in
whorls of 7 to 8 on a single petiole. Matured leaves were
dark green on the upper surface and light green on the
lower surface. The leaf laminar was elliptic in shape with
an acuminate to obtuse apex, entire margin, cuneate base
and pinnate reticulate venation. The leaf was papery in
texture and had a glabrous surface (Fig. 1. AB). The powdered leaf was coarse with a characteristic odour and a
bitter taste. The stem bark appeared greyish-brown on the
outer surface with longitudinal striations, mosses and
Parameter
Leaf
Stem bark
Odour
Characteristic
Characteristic
Colour
Deep green (adaxial)Light
green (abaxial)
Greyish- brown (outer)
Pale red (inner)
Texture of powder
Coarse
Sandy
Origin
-
Trunk
Type
Simple
-
Arrangement
Spiral/whorl
-
Shape
Elliptic
Margin
Entire
-
Apex
Acuminate - obtuse
-
Base
Cuneate
-
Venation
Pinnate
-
Glabrous
Moss, Cracks
Longitudinally striated
Surface
Plant Science Today, ISSN 2348-1900 (online)
480 KWATIA ET AL
Texture
Papery
Rough
-
Short (outer surface)
Fibrous (inner surface)
Petiole
Petiolate
-
Average length of leaf/cm
21.83 ± 3.04
-
Average width of leaf/cm
7.11 ± 1.51
-
Fracture
average length is presented as the mean ±SD [n=30]
Microscopic description
The leaf lamina displayed anticlinal polygonal straightwalled epidermal cells on the adaxial and abaxial surfaces.
The leaf was hypostomatous with anisocytic stomata distributed only on the lower surface (Fig. 2. AB). Both surfaces
free ending ultimate endings (veinlet terminations) were
observed (Fig. 2. C). The transverse section (T/S) of the leaf
midrib had an almost circular outline and a slightly protruded adaxial surface forming a pear-like shape (Fig. 2. D).
Below the cuticle was a row of irregularly shaped epidermal
cells. About four to five rows of closely packed polygonal
collenchyma cells, followed by loosely packed isodiametric
parenchyma cells were dispersed in the cortex. Tanniferous
cells were found among parenchyma in the cortex. The vascular bundle was arranged in a circular system surrounded
by a sheath of ruffled lignified sclerenchyma in the core. An
arch-shaped lignified xylem tissue was observed at the centre (Fig. 2. DE). The T/S of the petiole showed a similar cellular arrangement as that of the midrib. Epidermal cells in a
Fig. 2. Microscopy of the leaf and stem bark of U. heudelotii [A- upper surface of fresh leaf with straight-walled epidermal cells; B- lower surface of fresh leaf
with anisocytic stomata; C- veinlet terminations and vein islets; D, E- transverse section (T/S) of the midrib; F- T/S of the petiole; G- microscopy of powdered
leaf and stem bark; [EP- epidermal cells, PC-parenchyma cells; CO-collenchyma cells, SC-schelenchyma cells, TN-tanniferous cells, ST-stomata, VI-vein islet,
VT-veinlet termination, VB- vascular bundle, Sg- starch grain, Stc-stone cells, CaO-Calcium oxalate crystal, Ve- pitted vessel, Fi-fibre].
single row were followed by about six to eight rows of tightly
were glabrous with no trichomes. Reticulate venation pat- packed collenchyma cells. Loosely packed parenchyma
tern with generally four-sided vein-islets and few branched cells were observed in the cortex. Lignified sclerenchyma
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481
cells arranged in a circular pattern surrounded a central
vascular bundle. Several parenchyma cells occupied the
core around the vascular bundles (Fig. 2F). Microscopy of
the powdered leaf showed the presence of epidermal cells
and starch grains, while the stem bark powder had prismatic-shaped calcium oxalate crystals, stone cells, pitted
vessels and fibres (Fig. 2G).
Table 4. Fluorescence analysis of the leaf and stem bark of U. heudelotii
Sample + solvent / reagent
Visible light
UV
(254nm)
UV
(365nm)
NF
U. heudelotii Leaves
Powder + Water
Cream
Light green
Powder + Ethanol (95%)
Green
Pink
Brown
Powder + Ethyl acetate
Green
Pink
Brown
Quantitative microscopy
Powder + Chloroform
Cream
Light green
Cream
The leaf surface constants evaluated in this study included
the stomatal number, stomatal index, vein-islet number,
vein termination number and palisade ratio. The result is
presented as the mean ± standard deviation (Table 2).
Powder + Petroleum ether
Light green
Pink
Brown
Powder + Concentrated ammonia
Brown
Pink
NF
Powder + Concentrated sulphuric
acid
Brown
NF
NF
Powder + Concentrated hydrochloric acid
Green
Deep green NF
Powder + Ferric chloride
Green
Green
NF
Powder + Alcoholic Potassium
hydroxide
Green
Green
NF
Physicochemical studies
Table 2. Leaf surface constants for the fresh matured leaf of U. heudelotii
Leaf surface parameter
Results
Stomatal number /mm²
6.4 ± 1.67
Powder + Iodine solution
Green
NF
NF
Powder + Ammonia solution
(25%)
Brown
Green
NF
Stomatal index/%
22.1 ± 2.36
Vein islet number / mm²
6.0 ± 2.20
Vein termination number/ mm²
7.8 ± 2.58
Palisade ratio/ mm²
5.6 ± 0.89
values are presented as the mean ± SD [n=5]
The parameters evaluated in physicochemical evaluations
of the stem bark and leaf included the solvent extractive
values, ash values, pH and elemental content. Results obtained are presented in Table 3.
Table 3. Physicochemical evaluation of the leaf and stem bark of U. heudelotii
Parameter
Leaves
Stem Bark
Extractive values (% w/w)
Water extract
25.00 ± 0.338
28.00 ± 0.129
Ethanol extract
28.31± 0.318
37.31± 0.125
Ethyl acetate extract
35.04 ± 0.464
10.24 ± 0.113
Petroleum ether extract
32.80 ± 0.194
6.40 ± 0.191
Total ash
6.41 ± 0.208
5.01 ± 0.258
Acid insoluble ash
1.10 ± 0.115
3.10 ± 0.238
Water soluble ash
1.08 ± 0.044
0.28 ± 0.018
Water extract
3.79 ± 0.175
3.43 ± 0.070
Ethanol extract
5.23 ± 0.133
4.46 ± 0.095
0.480 ± 0.013
0.600 ± 0.030
Ash values (% w/w)
pH determinations
Elemental analysis (%)
Calcium (Ca)
U. heudelotii Stem bark
Powder + Water
Reddish brown Brown
Brown
Powder + Ethanol (95%)
Brown
Pink
NF
Powder + Ethyl acetate
Light green
Pink
Brown
Powder + Chloroform
Cream
Light
Cream
Powder + Petroleum ether
Light green
Pink
Powder + Concentrated ammonia
Reddish brown NF
NF
Powder + Concentrated sulphuric
acid
Brown
NF
NF
Powder + Concentrated hydrochloric acid
Brown
NF
NF
Powder + Ferric chloride
Brown
NF
NF
Powder + Alcoholic potassium
hydroxide
Brown
Green
NF
Powder + Iodine solution
Brown
Green
NF
Powder + Ammonia solution
(25%)
Brown
Purple
NF
NF- no fluorescence
Phytochemical screening
Qualitative phytochemical screening showed the occurrence of alkaloids, flavonoids, saponins, phytosterols, tannins, coumarins, reducing sugars and triterpenoids in both
the leaves and stem bark (Table 5). The total phenolics and
Table 5. Phytochemical constituents of the leaf and stem bark of U. heudelotii
Potassium (K)
0.924 ± 0.075
1.602 ± 0.162
Phytochemical
Test
Magnesium (Mg)
0.264 ± 0.020
0.336 ± 0.043
Reducing sugars
Phosphorous (P)
0.050 ± 0.001
0.117 ± 0.008
Alkaloids
Metal content (mg/kg)
Light pink
Leaves
Stem bark
Fehling’s test
+
+
Dragendorff’s test
+
+
Coumarins
Fluorescence test
+
+
Iron (Fe)
266.84 ±19.170
245.22 ± 0.175
Flavonoids
Alkaline reagent test
+
+
Lead (Pb)
0.0019 ± 0.0003
0.0025 ± 0.0002
Saponins
Frothing test
+
+
Copper (Cu)
15.54 ± 2.170
13.23 ± 1.910
Phytosterols
Liberman Buchard’s test
+
+
Zinc (Zn)
23.21 ± 3.075
19.19 ± 1.448
Tannins
Ferric chloride test
+
+
Terpenoids
Salkowski’s test
+
+
values are presented as the mean ± SD [n=3]
Fluorescence analysis
key: (+): detected
Characteristic fluorescence emissions by the stem bark and total flavonoid contents of the leaf and stem bark were deleaf powders in various solvents and reagents under visible termined using gallic acid (100, 50, 25, 12.5, 6.25, 3.12 µg/
and UV light is presented on Table 4.
mL) and quercetin (100, 50, 25, 12.5, 6.25, 3.12 µg/mL) as
Plant Science Today, ISSN 2348-1900 (online)
482 KWATIA ET AL
reference substances respectively. Thus, the TPC was calculated as milligram of gallic acid equivalent and TFC as milligram quercetin equivalent/gram of dried extract based on
their respective standard calibration curves (Fig. 3. AB). The
Fig. 3. Calibration curves for gallic acid (A) and quercetin (B) for determination of total phenolic and total flavonoid contents [concentrations used:
3.12, 6.25, 12.5, 25, 50, 100 µg/mL].
total phenolic content of the leaf and stem bark were respectively determined to be 219.2 ± 10.013 and 153.9 ±
1.602 mg/g gallic acid equivalent (GAE). The total flavonoid
content of the leaf was 1036 ± 33.3 while the stem bark had
310.2 ± 7.9 mg/g quercetin equivalent (QE).
UV and IR analysis
The UV spectra (Fig. 4) showed two ʎmax each at 203/279 nm
and 203/281nm respectively for the stem bark and leaf of U.
heudelotii. Prominent absorption was observed at 203 nm.
Similar UV absorption patterns were observed for the stem
Fig. 4. UV spectra of the of the leaf (A) and stem bark (B) MeOH extracts; IR
spectra of the leaf (C) and stem bark (D) MeOH extracts
bark and leaf suggesting the presence of similar constituents with extensive conjugated ring systems. Similarly, the
IR spectra of both leaf and stem bark extracts showed similar fingerprint with absorption bands mainly at 2900-3300
cm-1 (broad) for hydroxyl groups (-OH stretch) and around
1600 cm-1 for alkene groups (C=C stretch).
Discussion
Pharmacognostic studies comprise various qualitative and
quantitative tests performed on crude herbal drugs in order
to authenticate or establish their identity, purity and quality (21). In this study, the leaves and stem bark of U. heudelotii were evaluated for pharmacognostic, phytochemical
and physicochemical characteristics.
The study of a plant’s morphology through macroscopic and microscopic evaluations are crucial as they
serve as the simplest, quickest and easiest means of identihttps://plantsciencetoday.online
483
fying the plant in its natural habitat and helps in differentiating it from other related species (22). From the results,
the presence of hypostomatic leaves with anticlinal polygonal straight-walled epidermal cells are consistent generic
features previously observed in the foliar morphology of
Uapaca species (5). It was reported that pericytic stomata
occur in U. heudelotii (12). However, in the present report
anisocytic stomata having guard cells between two larger
subsidiary cells and one distinctly small one were generally
observed for this species as was also reported (5). Other
studies also report the presence of tetracytic stomata in U.
vanhouttei, trichomes in U. togoensis, U. vanhoutteii and U.
sansibarica (12). Apart from the generic anticlinal straightwalled polygonal epidermal cells, the presence of large tanniferous epidermal cells and absence of trichomes are also
distinguishing features observed U. heudelotii.
ethanolic extracts were relatively acidic (pH = 3.7 - 5.2). The
aqueous extracts being more acidic than the ethanol extracts.
For easy transportation and commercial purposes,
most crude plants are processed into their powdered
forms. Establishing standards for powdered plant materials
through microscopy and physicochemical analysis is therefore important as it aids in the detection of adulterants in
powdered crude drugs (23). Fibres, epidermal cells, stone
cells, calcium oxalate crystals and starch grains were observed in powdered samples. The presence of calcium oxalate crystals was also reported in U. staudtii and U. togoensis (12).
the normal production of oxygen-carrying red blood cells
(haemoglobin), needed for energy supply, normal immune
function and to prevent anaemia. Cu is required for the
maintenance of healthy bones, nerves and blood vessels
and also aids in iron utilization and immune function (30).
Heavy metals such as lead (Pb) on the other hand, are environmental pollutants and pose a great threat to human
health (31). Ingestion of large amounts of Pb is detrimental
to the immune, nervous, skeletal, renal, cardiovascular and
reproductive systems resulting in severe damage to the
heart, kidneys, brain and reproductive organs (30). Exposures to lead both prenatally and at early childhood is
linked to lower intelligence, learning deficits and impaired
motor function in children (30). The highest permissible
limit of lead (Pb) in medicinal herbs is 10 mg/kg according
to the Food and Agriculture Organization (FAO) (3). The
content of lead detected in the leaf and stem bark of U. heudelotii were 0.0019 and 0.0025 mg/kg respectively which
falls in range of permissible limit. Nevertheless, the elemental content of any plant drug may vary according to its
geographical location, mineral composition of the soil, climatic conditions as well as human activities (30). It must
however be noted that risk of danger associated with the
consumption of heavy metals depends on the average daily
dietary intake.
Qualitative phytochemical screening gives an indication of the major classes of phytoconstituents in a plant
sample which also contribute to its biological effect. The
current results were consistent with previous reports on the
stem bark and leaf of U. heudelotii (8, 10). The presence of
polyphenols in the plant may contribute significantly to the
plant’s therapeutic effect in traditional medicine such as its
use in the treatment of skin, respiratory, urinary and gastrointestinal infections. In a previous study, flavonoids from
the stem bark of U. heudelottii were shown to possess significant antibacterial activity (10). Polyphenols such as flavonoids, tannins and coumarins have been shown to complex bacterial cell membrane proteins, interfere with bacteAmong the surface constants studied for the leaf, the rial adhesion and cause enzyme deactivation leading to the
stomatal index remains relatively constant regardless of death of bacteria (26, 27).
the age and habitat of a specific plant species and is very
Foods or herbs containing minerals such calcium
useful for distinguishing species of the same genus. A sto- (Ca), phosphorous (P), magnesium (Mg), potassium (K), zinc
matal index (SI) range of 22.4-34% was previously reported (Zn), copper (Cu) and iron (Fe) are essential for the proper
for Uapaca species (12). In this study, the SI recorded was functioning of the human body and aids in the prevention
22.1 %, which falls in range with this previous report.
and treatment of several diseases (28, 29). Fe is required for
The estimation of extractive values determines the
extractive power of specific solvents i.e. the amount of
chemical constituents extractable by a particular solvent
under specified conditions (17). From the results obtained,
ethyl acetate and petroleum ether had the highest extractive power for the leaves while ethanol and water afforded
high extractive yields for the stem bark. This implies that
the constituents of the leaves may be less/mid-polar in nature while the stem bark has more polar constituents.
The ash content of a crude drug is the amount of
insoluble inorganic matter naturally occurring with the
plant or added to it deliberately to adulterate it for financial
gains (24). The acid-insoluble ash particularly specifies
adulteration with siliceous materials while the watersoluble ash gives information on the possibility of previous
extraction with water (25). The leaves and stem bark had a
total ash of about 5% and 6% respectively, implying that for
2 g of dried powdered leaf or stem bark of U. heudelotii the
residual matter including non-volatile impurities must be
approximately less than 10%. The acid-insoluble ash obtained was between 1-3% which is quite favourable as it
indicates low amounts of inorganic matter naturally adhering to the crude drug. The values would be useful in determining the quality of crude samples of U. heudelotii.
Conclusion
The present pharmacognostic studies on the leaves and
stem bark of U. heudelottii has provided standard macro
and micro-morphological features and physicochemical
properties that can aid in authentication of both whole and
powdered samples of the plant. Major classes of secondary
metabolites including phenolic compounds, saponins, alkaloids, triterpenes and sterols were identified. Future asThe average pH values obtained from aqueous and pects of this research may consider investigation of the
Plant Science Today, ISSN 2348-1900 (online)
484 KWATIA ET AL
pharmacognostic and physicochemical features of other 8.
closely related species in order to make a clear distinction
among common species in the region. Further phytochemical analysis shall consider identification of specific constituents in the plant.
Ngbolua K, Tshibangu D, Mpiana P, Mihigo S, Mavakala B,
Ashande M et al. Anti-sickling and antibacterial activities of some
extracts from Gardenia ternifolia subsp. jovis-tonantis (Welw.)
Verdc.(Rubiaceae) and Uapaca heudelotii Baill.(Phyllanthaceae).
J Adv Med Pharm Sci. 2015;2(1):10-19. https://doi.org/10.9734/
JAMPS/2015/13427
9.
Achika JI, Ayo RG, Oyewale AO, Habila JD. Antibacterial activity of
fractions of Uapaca heudelotii Bail. Synergistic effect with ciprofloxacin. Albanian J Pharm Sci. [Internet]. 2018 [cited 2021 Aug
14]; 11:1-7.
Acknowledgements
The authors appreciate the technicians in the Department
of Pharmacognosy of the Faculty of Pharmacy and Pharma- 10. Achika JI, Ayo RG, Oyewale AO, Habila JD. Flavonoids with antibacterial and antioxidant potentials from the stem bark of
ceutical Sciences, KNUST, Kumasi. This research was not
Uapaca heudelotii. Heliyon. [Internet]. 2020 [cited 2021, Aug 14];
supported by external funds.
6(2):e03381. https://doi.org/10.1155/2018/1920198
11. Kambale JK, Ngolua KN, Mpiana PT, Mudogo V, Tshibangu DST,
Wumba DMR et al. Evaluation in vitro de l’activité antifalcémiante
et effet antioxydant des extraits d’Uapaca heudelotii Baill.
KS and AYM conceptualized, designed and coordinated the
(Euphorbiaceae). Int J Biol Chem Sci. 2013;7(2):523-34. https://
study. Material collection macroscopic and microscopic
doi.org/10.4314/ijbcs.v7i2.9
Authors contributions
analysis were conducted by AKO and LG. Phytochemical, 12. Kadiri A, Ayodele A, Olowokudejo J, Uchemunefa DJ. Comparaphysicochemical and fluorescence analysis were done by
tive leaf epidermal morphology of five West African species of
Uapaca Bail (Phyllanthaceae Pro Forma Euphorbiaceae). NiEAK and AYM. All authors contributed to writing the manuger
J Bot. [Internet]. 2013 [cited 2021 Aug 14]; 7:54-60. Available
script, reviewed and approved the final version of the manfrom: https://plantstomata.wordpress.com/2015/10/19/stomatauscript.
in-uapaca/
Compliance with ethical standards
13. Evans WC. Trease and Evans Pharmacognosy. 15th ed. London:
Elsevier limited; 2002
Conflict of interest: Authors do not have any conflict of 14. Baidoo MF, Asante-Kwatia E, Mensah AY, Sam GH, Amponsah IK.
Pharmacognostic characterization and development of standinterests to declare.
ardization parameters for the quality control of Entada africana
Ethical issues: None
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