The plant Murraya koenigii (L.) Spreng (Rutaceae), commonly
known as Curry leaf-tree is used in the treatment of various diseases
by traditional medical practitioners. This plant is reported to have stimulant,
antidysentery (Adebajo et al., 2004), antidiabetic (Grover et
al., 2003), antioxidant, hypolipidaemic and antiatherosclerotic properties
(Vinuthan et al., 2007). Traditionally the leaves, bark and roots
of Murraya koenigii (L.) Spreng. are used as tonic and stomachic.
The bark and the roots are used as a stimulant, cure eruptions and the
bites of poisonous animals. The stems are very popular for cleaning the
teeth and are said to strengthen the gums and the teeth. Also the stems
are used as bitter, anthelminitic, febrifuge, anti-inflammatory, foul
ulcer, in treatment of vomiting, dysentery and flatulence (Parmar and
Kaushal, 1982; Nadkarni, 1995). The constituents identified in the plant
are alkaloids (Chakrabarty et al., 1997), glycosides, flavonoids
(Adebajo and Reisch, 2000), minerals (Narendhirakannan et al.,
2005) and volatile oils (Parmar and Kaushal, 1982). A complete study on
Pharmacognostic aspects has not been reported for the stems of M. koenigii
till now. Though the plant species could be easily distinguished on the
basis of the flowers, it becomes very difficult when the crude drug is
in the form of dried and cut pieces. Therefore, present investigation
was planned to have a detailed study on its pharmacognostic parameters.
MATERIALS AND METHODS
Plant materials: The plant M. koenigii was collected from
Mandsaur and positively identified by Dr. H. S. Chattree, Botanist, Govt.
Arts and Science College, Mandsaur. Voucher specimen (BRNCP/M/002/2006)
was deposited in the herbarium of Department of Pharmacognosy, BRNCP,
Pharmacognostic studies Morphological studies: Morphological studies
were done using simple microscope. The shape, size, color, taste and odor
of stems were determined.
Microscopic studies: Microscopic studies were done by preparing
thin hand sections of stem. The sections of stems were cleared with chloral
hydrate solution and then stained with phloroglucinol and hydrochloric
acid and mounted in glycerin. Separate sections were prepared and stained
with iodine solution for the identification of starch grains. The photomicrographs
of sections were taken with the help of CXR III camera. Powders (No. 60)
of the dried stems were used for the observation of powder microscopical
characters. The powdered drug was separately treated with phloroglucinol-HCl
solution, glycerin and iodine solution to determine the presence of lignified
cells, calcium oxalate crystals and starch grains.
Micrometry: Eyepiece micrometer was calibrated using stage micrometer
and the factor was calculated. With the help of eyepiece micrometer measurements
were done in transverse section of stem and in powder. The powder was
previously treated with chloral hydrate solution and stained with phloroglucinol
and HCl for phloem fibre, with lactophenol and iodine for starch grains
(Shanta et al., 2006).
Fluorescence study: Fluorescence study is an essential parameter
for first line Standardisation of crude drug. The crude drug was subjected
to this studies and its fluorescence pattern were noted. The powder material
was treated separately with different reagents and exposed to visible,
ultraviolet light (short and long U.V.) to study their fluorescence behavior
(Shanta et al., 2006; Goel et al., 1971).
Physicochemical parameters: Total ash, water-soluble ash, acid
insoluble ash and sulphated ash were determined. Petroleum ether (60-800),
acetone, chloroform, alcohol and water-soluble extractive values were
determined to find out the amount of components soluble in various solvents.
Moisture content and crude fibre content were also determined (Kokate,
1994; Anonymous, 1985).
RESULTS AND DISCUSSION
Macroscopic examinations: Murraya koenigii is an aromatic
and small tree up to 6 m in height and 15-40 cm in diameter. The young
stems are green in color with sweet aromatic odor and characteristic taste.
The outer surface is smooth, soft and glabrous.
The mature stems of Murraya koenigii are dark brown (unpeeled)
and Cremish brown (peeled) in color with slight aromatic odor and characteristic
taste. The outer surface is smooth and hard. The fracture of bark is splintery.
Microscopic examinations: The stem of Murraya koenigii
has a circular transaction and shows following features (Fig.
Epidermis: It is single layered, parenchymatous, uniseriate, unicellular,
tangentially elongated surrounded by thick cuticle (Fig.
2). The diameter of epidermal cells is 7-8-15 μm (Table
1). Epidermis exhibits 5-6 unicellular, uniseriate, covering trichomes
(Fig. 3). The length and width of trichome are 115-138-161
and 15-16-17 μm, respectively (Table 1).
Oil gland: Just below the epidermis, there are 6-10 schizolysigenous
oil glands (Fig. 4, 5) present, having
inner diameter of 46-76-115 μm and outer diameter of 61-94-130 μm
||Transverse section of the young stem
of Murraya koenigii Spreng showing primary growth at x 100
||Transverse section showing cuticle, layer of epidermis
and cortex region in young stem at x 450
||Transverse section showing trichomes
in young stem at x 450
Cortex: Continuous strands of 4-6 layers of compactly arranged
parenchymatous, polygonal cells constitute the cortex region of 292-298-303
μm (Fig. 2). The diameter of individual cell is
19-35-49 μm (Table 1). The cortex region shows the
presence of lignified sclerenchymatic cells of 30-40-50 μm (Fig.
6, Table 1).
Vascular bundle: The vascular system consists of a cylinder of
xylem produced towards the inside and a
||Microscopical measurements (Micrometry)
||Transverse section showing oil gland
in cortex region in young stem at x 450
||Transverse section showing oil filled
gland in cortex region in young stem at x 450
||Transverse section showing sclerenchymatous
cells in young stem at x 450
cylinder of phloem outward along with bi or triseriate medullary rays.
Vascular bundles are of collateral, conjoint and open type (Fig.
7, 8). The total region of xylem and phloem is of
73-97-119 and 38-64-95 μm, respectively. The distance between two
medullary rays is 61-59-92 μm (Table 1).
||Transverse section showing medullary
rays, xylem vessels and xylem parenchyma in young stem at x 450
||Transverse section showing xylem and
phloem parenchyma cells in young stem at x 450
Pith: Pith consists of thin walled polygonal, parenchymatous cells
bearing starch grains (Fig. 9, 10)
of 6.89-13.69 μm (Table 1). The total region of
pith is of 38-64-95 μm (Table 1).
At the secondary stage the primary cambium (in between the xylem and
phloem) produces secondary vascular tissues and the xylem parenchyma soon
becomes sclerenchymatous (Fig. 11). For the better protection
of the stem at the secondary stage, the cork-cambium originates in the
outer side i.e., in the epidermis itself and produces cork cells on the
outer side (total cork region is of 64-75-98 μm (Table
1) and a layer of phelloderm (secondary cortex) (Fig.
11) on the inner side. At secondary stage medullary rays become fully
developed i.e., penetrates inside the xylem region (Fig.
12). Oil glands remain persistent during secondary growth (Fig.
13). A region of unmodified cells is also observed just below the
xylem (Fig. 14).
Powder microscopy: The analysis of powder showed the presence
of covering trichome, lignified fibres, starch grains, cork cells, sclerenchymatic
cells, biseriate medullary rays, lignified xylem vessles (pitted, reticulate).
When treated with iodine, starch grains were also observed in the powder.
The results of micrometry and fluorescence analysis are presented in
Table 1 and 2, respectively. The total
ash, water soluble, acid insoluble and sulphated ash values of the plant
are shown in Table 3. Crude fibre content and
||Transverse section showing pith region in young stem
at x 450
||Transverse section showing starch grains in pith region
in young stem at x 450
||Transverse section showing bark region in mature stem
at x 450
||Transverse section showing developed Medullary rays
in xylem region in mature stem at x 450
||Transverse section showing bark along with oil gland
in mature stem at x 450
||Transverse section showing unmodified cells below xylem
region in mature stem at x 450
||Results of Fluorescence analysis of powder
||Determination of ash values (% w/w)
moisture content of dried powdered stems were determined and found to
be, 54.25 and 0.36 (% w/w), respectively. Extractive values (% w/w) of
dried powdered stems were determined and comparatively water soluble extractives
were found to be more in this species (Table 4).
As there is no pharmacognostic anatomical study on record of this drug
which is of great value, present study was taken up with a view to lay
down the microscopic standards, which could be used in deciding the
||Determination of extractive values (% w/w)
genuineness of the drug source. The drug was found to contain trichomes
and trichomes are epidermal outgrowths of considerable value for taxonomic
purposes. These outgrowths play a role in plant defense especially with
regard to phytophagous insects, avoiding insect feeding and oviposition
responses and the nutrition of larvae. They may be involved in the regulation
of temperature and water repellency as well (Duartea and Deburb, 2005).
Schizolysigenous oil glands were found below the epidermis and the volatile
oils are stored in these glands. Oils filled glands were also found in
The sclerenchymatic ring in the cortex has been described in this study.
The sclerenchymatic cell concentration is effective in withstanding environmental
pressures, such as damage by wind and to fend off herbivores (Metcalfe
and Chalk, 1988). Pith usually consists of parenchyma and serve
to store starch or secrete crystals and other ergastic substances (Dutta,
2001). The transverse section of pith region shows the presence of starch
grains in M. koenigii. These above mentioned arrangements along
with bi or triseriate medullary rays would be crucial in the identification
of this plant. Ash values, extractive values and fluorescence analysis
are few parameters, which normally are adopted to get the qualitative
information about the purity and standard of the crude drug. The macro
and the micro morphological standards discussed can be considered as a
distinguishing parameter to identify and decide the authenticity of this
drug and thus can be included as microscopic standards in Pharmacopoeias.