PHARMACOGNOSTIC STUDIES OF SOME INDIGENOUS MEDICINAL PLANTS OF PAKISTAN

Abid Mahmood, Mushtaq Ahmad, Asma Jabeen, Muhammad Zafar* and Saima Nadeem

DEPARTMENT OF BOTANY, UNIVERSITY OF ARID AGRICULTURE, RAWALPINDI

DEPARTMENT OF BIOLOGICAL SCIENCES, QUAID-I-AZAM UNIVERSITY, ISLAMABAD-PAKISTAN

mushtaqflora@hotmail.com

ABSTRACT

Medicinal plants constitute an effective source of traditional and modern medicines. The plant is a biosynthetic laboratory, not only for chemical compounds but also a multitude of the compounds. The present research work was confined to study the macro, microscopic features and analysis of powdered drug of Acacia modesta Wall., Acacia nilotica (L.) Delile, Berberis lycium Royle and Zanthoxylum alatum D. C. Prod. These studies were carried out in Botany laboratory of University of Arid Agriculture, Rawalpindi during 2004. These species are used as miswak (tooth brush) by local people of Pakistan in different areas. Anatomical features such as, fibres, parenchyma cells, vessels and pith were identified during microscopic studies. Powdered miswak of Acacia modesta Wall., Berberis lycium Royle and Zanthoxylum alatum D. C. Prod. were soluble in sulphuric acid only while insoluble in other solvents i.e., hydrochloric acid, acetic acid, benzene and water. Powdered miswak of Acacia nilotica was insoluble in these solvents. Powdered drug of these species did not retain their original colour in cold and hot tests and on dry filter paper, when mixed in various solvents.

Key words: Pharmacognosy, Indigenous medicinal plants, Pakistan.

INTRODUCTION

Since the beginning of human civilization, people have used plants as medicine. Perhaps as early as Neanderthal man, plants were believed to have healing power. The earliest uses are found in Babylonian circa 1770 BC in the code of Hammurabi and in ancient Egypt circa 1550 BC. In fact, ancient Egyptians believed medicinal plants to have utility even in the after life of their pharaohs. Plants have been recorded from the Gaza pyramids and can be found on display in a dark corner of Cairo Museum (Anna, 1993).

Pakistan is one of the few places on earth with such a unique biodiversity, comprising of different climatic zones with a wide range of plant species. Approximately 6000 plant species with medicinal properties are found in Pakistan. There is a dire need on the part of manufacturers of allopathic and herbal medicines to carryout systematic research on medicinal plants to save foreign exchange spend on their imports (Shinwari, 1989).

Traditional Unani medicine is a part of our culture and Pakistan is one of those countries where traditional Unani medicine is popularly practiced among the large segment of its population. It originated in Greece, founded by old ancient Greek philosophers and was used/documented by muslims during the glorious period of Islamic civilization. It was brought to the Indo-Pak subcontinent by muslim scholars and practiced here for centuries. It also benefited from the ayurvedic system of medicine, which was an important component of hindu civilization. Traditional Unani medicine heavily depends on medicinal plants, apart from using animals and minerals. Pakistan has a varied climate and is quite rich in medicinal herbs, though scattered over a large area. All the plants are growing wild and no systematic attempt has been made to carryout their pharmacognostic investigation of medicinal plants (Ahmad et al., 2003).

In Pakistan medicinal plants are primarily used by tibia dawakhanas (medical centers of indigenous physicians known as hakims). Unfortunately, very little attention has been paid to the pharmacognostic and ethno botanical aspect of plants, as hakims are only concerned with the floral and vegetative parts of medicinal plants without any regard to their botanical characteristics, or distribution in the various ecological zones of Pakistan. Herbs are not only used in the ayurvedic system of treatment but in the preparation of many allopathic and homeopathic drugs, no wonder these herbs are now being commercially exploited for the extraction of various ingredients (Haq, 1983).

Many of the plants which are used for various ailments have either not been properly investigated or the findings have not been correlated with phytochemical and pharmacological studies. Medicinal plants are those plants which are used directly or indirectly in the extraction of the drug for the treatment of ailments. Medicinal plant botanists are trying to explore the precious assets of medicinal plants for the suffering humanity. In the world 30% of the pharmaceutical preparations are manufactured from plants (Khan, 1979).

The present work is also in continuation of the exploration of medicinal wealth of Pakistan with special reference to Acacia modesta Wall., Acacia nilotica, Berberis lycium Royle, Zanthoxylum alatum D. C. Prod.

Keeping in view the medicinal importance of these selected species, the objectives of the present study are:

· To study the anatomy, powdered drug analysis and chemical tests of selected species.

· To investigate the indigenous medicinal plants for pharmacognosy and pharmacology which might be useful for further investigation by botanists, pharmacologists, microbiologists, phytochemists or some other academic disciplines.

· Studies of indigenous medicinal plants to disseminate the dynamics of local knowledge and challenge modern health care development.

MATERIALS AND METHODS

ØMATERIAL COLLECTION

The plant material was collected from the natural habitat of various localities. Branches of Acacia modesta Wall. and Acacia nilotica were collected from hills of district Attock. Branches of Berberis lycium Royle and Zanthoxylum alatum D. C. Prod. were collected from Murree hills. The branches were cleaned, washed and dried under shade for 20 days and in the oven for 24 hours at 100 °C. Then branches were cut into small pieces.

ØPOWDERED DRUG

The dried small pieces of branches were powdered by means of pistil and mortar and electric grinder. The macroscopic study was made. The physical characters of powdered drug that are colour, smell and taste were studied. The powdered drug was numbered and preserved in the bottles to avoid contamination.

ØHISTOLOGY

The microscopic features of the powdered drug were studied in 1% chloral hydrate, glycerine and Iodine solution. For permanent mounting the safranin, hemotoxylon and xylene were used. The various tissues were identified and microphotography were done with the help of Olympus microscope.

ØCHEMICAL ANALYSIS OF POWDERED DRUG

The simple method to determine the solubility of powdered drug was adopted. 5 gram powdered drug was mixed in 20 ml sulphuric acid, hydrochloric acid, acetic acid, benzene and water. Each test tube was shaken and boiled. Method followed is that of Evers and Smith (1955). The retention of original colour of powdered materials were noted in various solvents in cold and hot conditions. Filter paper was also used to find out change in colour.

RESULTS AND DISCUSSION

1. Acacia modesta Wall.

Macroscopic and Anatomical Features

Acacia modesta Wall. locally known as phulai belongs to family Mimosaceae. It is a medium size deciduous tree grows on stony grounds and rarely found on salt range. The flowers (March-May) are pale white to pale yellow fragrant growing in bunches. It is mainly used in making agricultural implements, fodder, timber, fuel and apicultural purposes. Medicinally it is used for gas trouble and its young twigs are used for cleaning teeth, dental disorders and dental problems. Its miswak is approximately 20 cm long with 2 cm in diameter. It is slightly curved and tough with pleasant taste.

Acacia modesta Wall. wood showed vessels with few cells and parenchyma cells. Fibres were also found. Pith consisted of rounded cells.

Chemical Analysis

The powdered miswak of Acacia modesta Wall. was soluble only in sulphuric acid. It did not retain its original dark yellow colour on dry filter paper and in various solvents by cold and hot tests (Table 1, 2). Dastagir and Haq (1995) also reported similar features of Acacia modesta Wall., Azadirachta indica and Dodonaea viscosa.

Table-1 Solubility and colour analysis of powdered drug of selected medicinal plants in various solvents by cold and hot method.

Acacia modesta Wall. Acacia nilotica (L.) Delile Berberis lycium Royle Royle Zanthoxylum alatum D. C. Prod

Solvents	Cold Test	Hot Test	Cold Test	Hot Test	Cold Test	Hot Test	Cold Test	Hot Test
	Colour solubility	Colour solubility	Colour solubility	Colour solubility	Colour solubility	Colour solubility	Colour solubility	Colour solubility
Sulphuric Acid	Dark Sol. brown	Brownish Sol. black	Reddish Insol. Brown	Dark Insol. Brown	Dark sol. Brown	Brownish Sol. black	Dark sol. Brown	Dark sol. Brown
Hydrochl-oric Acid	Greenish Insol.	Conker Insol.	Marool Insol.	Conker Insol.	Brownish Insol. Black	Conker Insol.	Greenish Insol.	Conker p.sol.
Acetic Acid	Yellow Insol.	Dark Insol. Yellow	Light Insol. Red	Light Insol. Red	Light Insol. Red	Copper Insol.	Light Insol. Red	Golden Insol. Brown
Benzene	Yellow Insol.	Dark Insol. Mustard	Light Insol. Mustard	Light Insol. Brown	Light Insol. Mustard	Mustard Insol.	Mustard Insol.	Dark Insol. Mustard
Water	Light Insol. Yellow	Light Insol. Yellow	Butter Insol. Scotch	Golden Insol. Brown	Light Insol. Yellow	Dark Insol. Brown	Golden Insol. Brown	Brown Insol.

Table-2 Colour analysis of powdered drug of selected medicinal plants in various solvents with known volume by filter paper.

Acacia modesta Acacia nilotica Berberis lycium Zanthoxylum alatum

Solvents

volume

Actual colour of powdered drug

Colour in solvents

Colour on filter paper

volume

Actual colour of powdered drug

Colour in solvents

Colour on filter paper

volume

Actual colour of powdered drug

Colour in solvents

Colour on filter paper

volume

Actual colour of powdered drug

Colour in solvents

Colour on filter paper

Sulph-uric Acid

4ml

Dark Brown

Dark Brown

conker

4ml

Light maroon

Reddish Brown

Light brown

4ml

Light brown

Dark brown

Dark copper

4ml

Dark grey

Dark brown

Dark copper

Hydro-chloric Acid

4ml

Dark Brown

Greenish

No. colour

4ml

Light maroon

Maroon

Light copper

4ml

Light brown

Brownish black

No. colour

4ml

Dark grey

Greenish Brown

No. Colour

Acetic Acid

4ml

Dark Brown

Yellow

No. colour

4ml

Light maroon