Pharmacognostical Evaluation of Mussaenda erythrophylla Linn leaves

M. Chinna Eswaraiah*, A. Elumalai and N. Manasa

Department of Pharmacognosy, Anurag Pharmacy College, Ananthagiri (V), Kodad(M), Nalgonda (Dt), Andhra Pradesh, India, 508 206.

ABSTRACT:

Mussaenda erythrophylla is an important Ayurvedic plant, belongs to the family Rubiaceae. The present study deals with a detailed pharmacognostical study on the leaf of M. erythrophylla. Literature survey reveals the presence of flavonoids, terpenoids, carbohydrates, tannins and glycosides. The physio-chemical, morphological, histochemical and UV spectrophotometric profile presented in this paper will help in the identification of the drug and identifying the bio-marker responsible for therapeutic activity.

KEYWORDS: Mussaenda erythrophylla, Pharmacognostical study, Rubiaceae.

INTRODUCTION:

Mussaenda erythrophylla (Linn) Schumach. (Family: Rubiaceae) known as Krishnakeli in Sanskrit, is an evergreen shrub found throughout Asia and India^1,2. M. Pubescens M. lancipetala and M. frondosa are the other species of Mussaenda. M. erythrophylla is a native of tropical coasts and slough gardens in Andhra Pradesh and its leaves are prescribed in the Ayurvedic literature for the treatment of rheumatism and hepatoprotective conditions³. M. erythrophylla is an evergreen shrub with silky, hairy and soft medium leaves, terminal panicles with tubular flowers, white or cream coloured corolla, with a diameter of 2cm, flowers are bisexual and red to pink in colour. Different parts like root, stem and leaves are used for the treatment of various diseases like cough, dyspnoea, leprosy, jaundice and stomach disorders. In Ayurveda, the properties are tikshna (sharp). It has a taste of bitter. Despite the abundant medicinal uses attributed to this plant, there are no pharmacological reports on the leaf of this plant⁴.Hence this research paper deals with the pharmacognostical studies, phytochemical screenings and UV spectroscopy profile of ethanolic extract. This profile can offer a basis for proper identification, collection and investigation of the plant and can possibly help to differentiate the drug from its other species.

MATERIALS AND METHODS:

Plant materials:

The leaves of M. erythrophylla were collected from medicinal plant garden of Anurag Pharmacy College. The authentification of the plant was done by Prof. M. Venkaiah, Dept. of Botany, Andhra University, Visakhapatnam. A voucher E01/12 has been deposited in the museum of the department of Pharmacognosy, Anurag Pharmacy College, Kodad, Andhra Pradesh. For the microscopic study, the leaves were immersed into alcohol for 15days to become soft and then cross sections obtained from an electronic microscope. Staining and mountaining were done by following the usual procedures of plant micro-techniques. The respective diagram was sketched with a help of camera lucida (from slides, 40 X) and digital camera (from dissecting microscope, 10X).

Pharmacognostical studies:

Morphological characters like size shape, apex, margin, surface and colour were carried out. Microscopic characters like epidermal cell number, stomatal index, vein islet number, vein termination, and trichomes of both the surfaces was carried out by using standard procedures^5,6.

Physiochemical analysis:

Different physiochemical analysis like ash values⁷, extractive values⁸ and fluorescence analysis⁹ were carried out according to the official methods prescribed in Indian Pharmacopoeia and the WHO guidelines on quality control methods for medicinal plant materials.

Preliminary phytochemical screening:

Preliminary screening was carried out by using standard procedures described by Harbone^{10, 11}.

UV Profile:

10µl of methanolic extract of leaves of M.erythrophylla was qualitatively determined by UV spectrophotometer.

RESULTS:

Macroscopic characters:

Leaf: leaf is simple, alternate, opposite, hairy and sessile (Figure 1). The upper surface is pale green and glabrous, while lower surface is green, oblong to elliptic shape, entire margin, acute apex and reticulate venation.

Figure 1: Mussaenda erythrophylla

Microscopical characters:

T.S. of petiole:

The vascular strand is shallow, wide and bicollateral. The strand consists of four or five xylem elements in parallel rows. They are angular, thick walled and are in radial multiples. Phloem occurs as small clusters in both the lower and upper parts of the xylem arc, the xylem elements are 20 µm wide (Figure 2, 3).

T.S. of leaf margin:

The marginal part of the leaf is in conical, measuring about 300µm thick. The epidermal cells are smaller and thick walled. Presence of compact parenchyma cells without differentiation of palisade and spongy parenchyma (Figure 4, 5).

T.s of central part of the lamina:

The lamina is smooth and even on both surfaces. It is 420 µm thick. Both epidermal layers are thin with squarish cells along with prominent cuticle. The epidermis is 20 µm thick. The lamina is amphistomatic (stomata occur on both surfaces). The mesophyll tissue is differentiated into adaxial zone of three layers of short cylindrical compact palisade cells and abaxial zone of lobed spongy mesophyll cells which form loosely reticulate aerenchyma. The lateral vein is large circular and collateral. It consists of a few xylem elements and phloem elements surrounded by parenchymatous bundle sheath.

Figure 2: T.s of petiole (40X), AdS–Adaxial side, GT–Ground Tissue, Ph–Phloem, X–Xylem.

Figure 3: Central section of petiole (10X), AdP–Adaxial side. Figure 4: T.s of leaf margin (10X), AdE–Adaxial side, LV–Lateral vein; LM–Leaf margin, PM–Palisade mesophyll, SM–Spongy mesophyll.

Figure 5: T.s of central part of the lamina (10X), BS – Bundle sheath.

Venation type:

The veins are thick and straight, they form dense reticulate venation with distinct vein-islets. The vein terminations are thick and short, either simple or lobed ones, the lobes are being unequal (Figure 6,7).

Figure 6: Paradermal sections of the lamina (10X)

Figure 7: VI - Vein islet; VT - Vein termination.

Powder microscopy:

The leaf powder when examined under the microscope exhibits the following elements;

1. Epidermal trichomes:

Epidermal trichomes of curious type are abundant in the powder. They are unicellular, unbranched, thin walled, dilated and club shaped. They are either straight or curved. They have short, unicellular stalk cell with which they are attached with epidermis. No specific inclusions are seen in the cells (Figure 8,9).

2. Epidermal fragments:

Small fragments of adaxial epidermis are commonly seen in the powder. The adaxial epidermal feelings exhibit small polygonal epidermal cells with fairly thick, straight walls.

4. Stomata:

A stoma is encircled by five or more subsidiary cells. Some of the stomata are paracytic type. The abaxial epidermal peeling shows epidermal cells with thin straight walls. These are small circular thick walled cells in the epidermal layer which are the basal cells of the epidermal trichomes. The epidermal trichomes are surrounded by a ring of triangular rosette cells (Figure 10,11).

Figure 8: Adaxial epidermal layer (40X), EC–Epidermal cells, GC–guard cells, SC–Subsidary cells.

Figure 9: Abaxial epidermal layer (40X), TC–Trichome bearing cells.

Figure 10: epidermal trichomes in the leaf powder (10X); B - Body cell

Figure 11: ST - Stalk cell.

Macroscopic and microscopic analysis:

The stomatal number, stomatal index, vein islet number, vein termination number, total ash, water soluble ash, alcohol and water soluble extractive values of leaf powder are given in table 1.

Table 1: Macroscopic and microscopic analysis of leaf powder

Shape of epidermal cells

Polygonal

Size of epidermal cells

Upper surface

Lower surface

2.9×10³-4.3×10³µ²

2.1×10³-3.7×10³µ²

Total number of cells/sqmm

Upper surface

Lower surface

105

196

Stomatal index

Adaxial side

Abaxial side

Stomatal number

Upper epidermis

Lower epidermis

50-52

46-48

Stomatal complex length

24-29 µ

Palisade ratio

9-11

Vein termination number

Vein islet number

Ash values

Total ash

Acid insoluble ash

Water soluble ash

Sulphated ash

9.45%w/w

1.82%w/w

3.27%w/w

2.46%w/w

Extractive values

Water soluble extractive

Alcohol soluble extractive

6.9%w/w

9.4%w/w

Preliminary phytochemical analysis of leaf powder:

A known quantity of dried powder was extracted in a soxhlet with methanol (70-90⁰C) for 24 hrs and tested for different phytochemical constituents. It reveals the presence of carbohydrates, glycosides, flavonoids, tannins and saponins. The results of phytochemical analysis were presented in Table 2, fluorescence analysis in Table 3 and UV scan spectrum in Figure 12.

Table 2: Preliminary phytochemical analysis of leaf powder

Test	Pet. ether Extract	Methanolic extract
Carbohydrates	+	+
Alkaloids	-	-
Glycosides	+	+
Steroids	-	-
Flavonoids	+	+
Tannins	+	+
Phenols	-	-
Gums	-	-
Proteins	-	+

Table 3: Fluorescence analysis of leaf powder

Treatment	Under ordinary light	Under UV light (366 nm)
Powder as such	Green	Yellowish green
Powder + 1N NaOH(Aqu)	Dark green	Pale green
Powder + 1N NaOH (Alc)	Dark green	Fluorescent Green
Powder + 1N HCL	Green	Pale green
Powder + Ammonia	Brown	Dark brown
Powder + Iodine	Dark green	Dull green
Powder + FeCl₃	Brownish green	Blackish green
Powder + 1N H₂SO₄	Green	Light green
Powder + 1N HNO₃	Light green	Fluorescent Green
Powder + Acetic acid	Pale red	Light red

Figure 12: UV Scan spectrum of methanolic extract of leaf powder

CONCLUSION:

The results of macroscopical, microscrocopical characters, ash values, extractive values, fluorescence analysis, phytochemical screenings and UV analysis of Mussaenda erythrophylla leaf powder can be considered as identification parameters. This present work might be useful in authentication purpose.

ACKNOWLEDGEMENT:

Authors are grateful thanks to Anurag Pharmacy College, Kodad for carrying out this research study.

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Received on 27.04.2012

Modified on 08.05.2012

Accepted on 30.05.2012

Research Journal of Pharmacognosy and Phytochemistry. 4(4): July- August 2012, 197-200