INTRODUCTION:

Medicinal plants have been a major source of cure for human diseases since time immemorial. It is no wonder that the world’s one-fourth population i.e. 1.42 billion people, are dependent on traditional medicines for the treatment of various ailments¹. Medicinal herbs are moving from fringe to main stream use with a greater number of people seeking remedies and health approaches free from side effects caused by synthetic chemicals.

Recently, considerable attention has been paid to utilize eco-friendly and bio-friendly plant based products for the prevention and cure of different human diseases. Considering the adverse effects of synthetic drugs, the Western population is looking for natural remedies, which are safe and effective. It is documented that most of the World’s population has taken in traditional medicine, particularly plant drug for the primary health care ². The Indian flora offers a variety of plants having medicinal properties. These plants can be exploited to find out effective alternative to synthetic drugs ³.

MATERIALS AND METHODS:

Leucas zeylanica was subjected to pharmacognostic study. The various methods used in the study included organoleptic study, fluorescence analysis and preliminary phytochemical studies.

Table- 1: Organoleptic study of the powder

1.	Colour	Deep green
2.	Odour	Characteristics
3.	Taste	Mucilaginous and slightly bitter

Table- 2: The fluorescence analysis of the powder of Leucas zeylanica

S.No	Treatment with chemical reagents	Observation
1.	Powder as such	Light green
2.	Powder + 1N Sodium hydroxide in methanol	Green
3.	Powder + 1N Sodium hydroxide in water	Green
4.	Powder + 50% Hydrochloric acid	Blackish grey
5.	Powder + 50% Sulphuric acid	Blackish green
6.	Powder + 50% Nitric acid	Light green
7.	Powder + Petroleum ether	Green
8.	Powder + Chloroform	Green
9.	Powder + Picric acid	Greenish blue
10.	Powder + 5% Ferric chloride solution	Green
11.	Powder + 5% Iodine solution	Deep brown
12.	Powder + Methanol	Green
13.	Powder + (Nitric acid + Ammonia)	Light green

Table- 3: The behaviors of the leaf powder of Leucas zeylanica when treated with different chemical reagents

S.No	Treatment with chemical reagents	Observation
1.	Powder as such	Light green
2.	Concentrated Hydrochloric acid	Blackish green
3.	Concentrated Sulphuric acid	Deep brown
4.	Concentrated Nitric acid	Light yellow
5.	Glacial acetic acid	Blackish green
6.	5% Sodium hydroxide solution	Yellowish green
7.	5% Potassium hydroxide solution	Blackish brown
8.	5% Ferric chloride solution	Light brown
9.	Picric acid	Yellow
10.	Ammonia	Reddish Brown
11.	Powder +1N Sodium hydroxide in methanol	Yellowish green
12.	Powder + 1N Sodium hydroxide in water	Deep green

Organoleptic study:

The powder of Leucas zeylanica was used for studies. The colour variation and taste were the basis for this test as given by Jackson and Snowdown⁴.

The fluorescence properties were studied under UV light adopting the method described by Kokoshi and Chase and Pratt ^5,6. The behavior of the samples with different chemical reagents was studied and fluorescence characters were observed on long UV light at 254nm.

About 20 gm of the powder of Leucas zeylanica was weighed accurately and mixed with 250 ml of hot water. After 1hour it was filtered and the supernatant was used as the extract. The preliminary phytochemical test of this extract was performed by specific reagents. These extracts were subjected to qualitative chemical tests for detection of various plant constituents.

RESULTS AND DISCUSSION:

The pharmacognostical characters of the leaf powders have been studied by screening the same through varying parameters.

The investigation on organoleptic study of leaf powder of Leucas zeylanica indicated the characters like colour, odour and taste. The colour of the leaf powder showed greenish grey colour. The taste and odour of the leaf powders were also tested. The taste of the leaf is mucilaginous and slightly bitter and on analysis the leaf powder gives a characteristic odour (Table 1).

The leaf powders are treated with various chemicals exhibited various colours in the UV light. When the powder was treated with aqueous 1 N NaOH and 50% H₂SO₄ the leaf powder exhibited varied green and blackish green colours in UV light and the results are depicted in Table 2.

When the leaf powders were treated with chemicals like FeCl₃, HCl, HNO₃, picric acid, NH₃, NaOH+methanol, Iodine solution, etc various shades of green, yellow, light brown, deep brown, yellowish green, etc colours were obtained (Table 3)⁷.

Pharmaceutical preparation derived from natural resources such as vegetables often contain compounds that contribute the antimicrobial defense systems and apparently play a role in the protection against degenerative diseases.

In the present study, a phytochemical screening of the crude methanolic extract was carried out to detect the active constituents such as alkaloids, flavonoids, gums, tannins, steroids, reducing sugars, glycosides and saponins. All the phytochemical tests showed negative results except alkaloids, steroids, tannins, flavonoids and glycosides. The results are depicted in Table 4.

CONCLUSION:

The results of organoleptic study offer a scientific basis for the traditional use of Leucas zeylanica which possess characters like deep green, characteristic odour and mucilaginous and slightly bitter taste. The leaf powders when treated with various chemicals exhibited various colours in the UV light All the phytochemical tests showed negative results except alkaloids, steroids, tannins, flavonoids and glycosides.

REFERENCES:

1. Reddy, K.J. (2004): Medicinal plant research scenario in India, Info concepts India Inc., pp.25-28.

2. Dubey, N.K., Kumar, R. and Tripathi, P. (2004): Global promotion of herbal medicine: India’s opportunity, Current Science, 86(1), pp.37-41.

3. Gaikwadi, S.S., Vadlamudi, V.P., Waghmaee, S.P., Maral, V.J., Ranteke, V.D. and Dhok, A.P. (2003): Phytochemical analysis of aqueous extract of few medicinal plants, PKV. Res. J., 27(1), pp.91-92.

4. Jackson, B.P. and Snowdown, D.W. (1968): Powdered vegetable drugs, Cheer Chil Ltd., London, pp.25.

5. Kokoshi, G.J., Kokoshi, J.R. and Sharma, F.J. (1958): Fluorescence of powdered vegetable drugs under ultra violet radiation, J. Amer. Pharm. Assn., 38(10), pp.715-717.

6. Chase, C.R. and Pratt, R.F. (1949): Fluorescence of powdered vegetable drugs with particular reference to the development of systems of identification, J. American Pharm. Assoc., 38, pp.324-333.

7. Pandey, H.C., Dixit, R.S. and Sharma, H.P. (1984): Addition to the Pharmacognosy of Kalimulri (Curculigo orchioides), Bull. Med. Ethnobot. Res., 5(1-2), pp. 55-56.

Received on 02.05.2012 Accepted on 12.09.2012

Asian J. Pharm. Res. 2(4): Oct. - Dec. 2012; Page 142-143

Extract	Alkaloids	Gums	Steroids	Flavonoids	Reducing Sugars		Saponins		Tannins	Glycosides
Methanol	+	-	+	+	_	_		+		+