PHARMACOGNOSTICAL INVESTIGATIONS ON IPOMOEA AQUATICA FORSK.

PHARMACOGNOSTICAL INVESTIGATIONS ON IPOMOEA AQUATICA FORSK.

Mital N. Manvar

Department of Pharmacognosy, Atmiya Institute of Pharmacy, Yogidham Campus, Kalawad road, Rajkot, Gujarat, India

ABSTRACT

Plants are a great source of medicines, which are useful in the treatment of various diseases. Ipomoea aquatica Forsk of family Convolvulaceae commonly known as Kalmisag or Nalanibhaji is being used as a green leafy vegetable and have great medicinal value in Indian medicine. It is used in Unani System of Medicine as carminative, lessens inflammation, useful in fever, jaundice, biliousness, bronchitis and liver complaints. In present investigation, the detailed pharmacognostic study of Ipomoea aquatica Forsk leaf is carried out to lay down the standards which could be useful in future experimental studies. The study includes macroscopy, microscopy, preliminary phytochemical screening and physicochemical evaluation.

Microscopy

INTRODUCTION: Herbal drugs play an important role in health care programs especially in developing countries. Ancient Indian literature incorporates a remarkably broad definition of medicinal plants and considers all plant parts to be potential sources of medicinal substances ¹.

Medicinal plants have been receiving great attention worldwide by the researchers because of their safe utility. The curative properties of medicinal plants are mainly due to the presence of various complex chemical substances of different composition which occur as secondary metabolites ².

However, a key obstacle, which has hindered the acceptance of the alternative medicines in the developed countries, is the lack of documentation and stringent quality control. So it becomes extremely important to make an effort towards standardization of the plant material to be used as medicine. The present work was undertaken to study pharmacognostic characteristics and physicochemical evaluation of leaves of Ipomoea aquatica Forsk.

Ipomoea aquatica Forsk (Synonym. Ipomoea reptans Linn.) of family Convolvulaceae commonly known as kalmisag or nalanibhaji or water-spinach ; is a perennial herb found throughout India, Ceylon, Tropical Asia, Africa and Australia ³.

Ipomoea aquatica  use as carminative, lessens inflammation; useful in fever, Jaundice, biliousness, bronchitis, liver complaints in Yunani system of medicine; also use in nervous and general debility of female in Assam; stem and leaves use in febrile delirium in Cambodia ⁴.

Leaves and flowers of Ipomoea aquatica shows antioxidant activity ^{5, 6}. Leaves of Ipomoea aquatica possess oral hypoglycaemic activity in streptozotocin induced diabetic Wistar rats and Type II diabetic patients ⁷. Methanol extract of leaves of Ipomoea aquatica shows hypolipidemic activity ⁸.

MATERIALS AND METHODS:The leaves of the plant Ipomoea aquatica were collected from Rajkot district of Gujarat, India. The plant material was identified by Botany Dept., Kotak Science College, Rajkot and a voucher specimen (Voucher No. ARGH-10) has been retained in Department of Pharmacognosy, A. R. College of Pharmacy, Vallabh Vidyanagar, Gujarat. Fresh leaves were used for macroscopical and microscopical studies. Coarse powder (# 60) of leaves was used to study microscopical characters of leaf, physicochemical parameters and phytochemical investigation. The detailed pharmacognosic studies of the plant leaf were carried out according to well known methods and procedures ^9-13. All the chemicals and solvents used in experiment were of analytical grade.

RESULTS:

Macroscopic Characters: Ipomoea aquatica is an herb. The leaves are simple, opposite, ovate to oblong shape; having acute apex, reticulate veination and glabrous surface. The base of leaves usually dilated, cordate to hastate. Leaves have entire margin and long petiole.  Organoleptic evaluation of the leaf powder revealed that leaf powder is pale green in color, with a characteristics odour and taste.

Microscopic Characters: Transverse section of leaf shows typical dorsiventral structure. Epidermis is single layered with cuticle. Lamina is differentiated in two layers, spongy and palisade tissues. There are three layers of palisade cells found below upper epidermis. Midrib portion consist epidermis is as in lamina; collenchyma cells present below and upper layer of epidermis and vascular bundle consist of xylem and phloem. A unicellular trichomes, paracytic stomata and rosetts of calcium oxalate crystals found in the lamina and midrib portion of leaf (Figure A, B and C). Leaf constants such as stomatal number, stomatal index, vein-termination number and vein-islet number were measured. The results are shown in table 1.

TABLE 1: LEAF CONSTANTS

X= magnification power

Powder Microscopy: The fine powder was mounted in glycerin as well as stained (phlorogucinol + HCL). Observation of microscope showed presence of unicellular trichomes, paracytic stomata, rosettes of calcium oxalate crystals, epidermal cells, xylem vessels and so on (Figure D, E and F).

Physiochemical Parameters: Ash values of a drug give an idea of the earthy matter or the inorganic composition and other impurities present along with the drug. Extractive values are primarily useful for the determination of exhausted or adulterated drugs. The results of these parameters are shown in table 2.

TABLE 2: PHYSIOCHEMICAL PARAMETERS OF LEAF

Preliminary Phytochemical Screening: Preliminary phytochemical screening mainly revealed the presence of phytosterols, flavonoids, carbohydrates and proteins.

DISCUSSION: In the present investigation, the detailed pharmacognostic account of is given which includes macroscopic and microscopic characters, which will be helpful for the correct botanical identification of the drug. Leaves of Ipomoea aquatica possess abundantly unicellular trichomes on both epidermises, paracytic stomata found which are comparatively more on lower epidermis, rosettes of calcium oxalate found in lamina as well as in midrib region. Ash values, extractive values and leaf constants can be used as reliable aid for detecting adulteration. The information obtained from preliminary phytochemical screening will be useful in finding out the genuinity of the drug. Hence it was thought worth to investigate pharmacognostic profile of the leaf will assist in standardization for quality, purity and sample identification.

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