Pharmacognostical Studies on Thespesia populnea Bark

 

R Parthasarathy1, R Ilavarasan2, CM Karrunakaran1

1Bharath University, Selaiyur, Chennai-600 073, Tamil Nadu.

2Captain Srinivasa Murthi Drug Research Institute for Ayurveda and Siddha, Chennai-600 109, Tamil Nadu.

 

ABSTRACT

Thespesia Populnea is a reputed ever green tree belonging to the family malvaceae; commonly known as Indian tulip tree. The plant is distributed tropical regions and coastal forest in India. It is well known and all the parts are used in Indian system of medicine. The plant has been used as astringent, antibacterial, hepatoprotective, haemostatic, anti-diarroheal and anti-inflammatory. The scientific parameter is necessary to identify the exact plant material and to find its quality and purity. The present study deals with various pharmacognostical examinations like organoleptic or macroscopical characters, microscopical or anatomical studies, physical evaluation and preliminary phytochemical screening of various successive extracts were carried out and the parameters were reported. These studies indicated the possible information for correct identification and standardization of this plant material.

 

KEYWORDS:  Thespesia populnea, bark macroscopy, bark microscopy.

 

INTRODUCTION:

Thespesia populnea soland ex correa (family malvaceae) is a large tree found in the tropical regions and coastal forests in India and cultivated in the gardens. All the parts of the plant used in traditional system of medicine. The bark, leaves, flower and fruits are useful in cutaneous infection such as scabies, psoriasis, eczema, ringworm, and guinea worm. The decoction of the bark is commonly used for the treatment of skin and liver diseases. A compound oil of bark and capsules is useful in urethritits and gonorrhea. The bark, root, fruits were used in dysentery, cholera and hemorrhoids1.  The fruits of the plant are used in ayurveda for the control of diabetes2. The barks and flowers posses astringent, hepatoprotective, antioxidant and anti-inflammatory activities in rats3,-6.

 

The leaves and bark of this tree are still used to produce oil for the treatment of fracture wounds and as an anti-inflammatory poultice applied to ulcers and boils, as a folk medicine6. Gossypol was found to be the major component of Thespesia populnea7 producing anti-fertility effects in rats8,9 as well as in human beings10. Four naturally occurring quinones viz thespone, thespesone, mansonone-D, and mansonone-H have been extracted from heart wood of the plant11. The phytochemical study of bark reveals the presence of gossypol, tannin and coloring matter12.

 

Lack of proper standard of medicinal plants may lead to usage of substandard drugs which will cause damage to the faith on traditional system of medicine. Therefore scientific method must be developed to identify and maintain quality of plant drugs. With this aim the present investigation was planned to study the pharmacognostical aspects of Thespesia populnea bark.

.


Table 1: Loss on drying and ash values of powdered stem bark of Thespesia populnea

Parameters

Result 

Loss on drying

5.46

Ash values

1) Total ash

 

4.72

2) Acid insoluble ash

0.96

3) Water soluble ash

3.42

 

FIG-1: TS of Thespesia populnea bark.

Co: cortex; Ph: pholem; Fi: fissures; Pe: periderm; DR: dilated rays.

 

MATERIALS AND METHODS:

Plant materials:

The fresh bark from about 3-5 years old tree were collected from our Salaiyur University campus in Chennai, India. The plant material was taxonomically identified and authenticated by Director, Plant Anatomy Research Centre, Chennai

 

A voucher specimen (PARC/236/07) has been deposited in the herbarium of the same department. Then the stem barks were shade dried at temperature 25-300.

 

Pharmacognostical studies:

Organoleptic or Macroscopical character:

The dried stem barks were also subjected to investigation. Studies, such as shape, size, outer surface, inner surface, fracture, taste and odour of bark, were carried out. A yellow exudates was oozed out from the fracture surface.

 

Anatomical studies or Microscopical character:

Preparation of specimen:

The bark were cut into required size and fixed in FAA (Formalin 5ml + Acetic acid 5 ml + 70% Ethanol 90 ml). After 24 hrs of fixing, the specimens were dehydrated with graded series of tertiary butyl alcohol. Infiltration of the specimens was carried by gradual addition of paraffin wax (melting point 58-600C) until tertiary butyl alcohol solution attained super saturation. The specimens were cased into paraffin blocks.

 

Sectioning:

The paraffin embedded specimen was sectioned with the help of rotary microtome. The thickness of the section was 10-12 µm. After dewaxing the sections were stained with toluidine blue. Since toluidine blue is a polychromatic stain, the staining results were remarkably good and some phytochemical reactions were obtained. The dye rendered pink color to the cellulose walls, blue to the lignified cells, dark green to suberin, violet to the mucilage, blue to the protein bodies etc., wherever necessary sections also stained with safranin and fast green and iodine (For starch)13,14.

 

FIG-2: TLS of Thespesia populnea bark.

 

Photomicrographs:

Microscopic descriptions of tissues are supplemented with micrographs wherever necessary. Photographs of different magnifications were taken with Nikon Labphot-2 microscope units. For normal observations bright fields was used. For the study of crystals, starch grains and lignified cells polarized light were employed. Since these structures have birefringent property, under polarized light they appear bright against dark back ground.

 

Physico-chemical evaluation:

Physical parameters such as loss on drying, total ash, acid insoluble ash, water soluble ash were determined as per the Indian Pharmacopeia15. All the results were recorded carefully (Table no: 1).

 

Phytochemical screening:

The dried and powdered stem bark was subjected to preliminary phytochemical screening for qualitative detection of phytoconstituents. The dried and coarsely powdered stem bark (100 g) was extracted successively with petroleum ether (40-60ºC), chloroform (59.5-60ºC), ethyl acetate (76.5-77.5ºC), and ethanol (90%) in a soxhlet extractor by continuous hot percolation. Finally the marc was macerated with chloroform water. Each time before extracting with the next solvent of higher polarity the powdered drug (marc) was dried in a hot air oven below 50ºC for 10 minutes. Each extract was concentrated by distilling off the solvent, which was recovered subsequently. The concentrated extracts were evaporated to dryness and the extracts obtained with each solvent were weighed. Their percentages were calculated in terms of initial air dried plant material. They are tabulated (Table no: 2)16.

 

 


Table 2: Results of phytochemical screenings of successive extracts of stem bark of Thespesia populnea

Constituent

Pet. Ether extract

Chloroform extract

Ethyl acetate extract

Ethanol extract

Aqueous extract

Alkaloids

-

-

-

-

-

Carbohydrates

-

-

-

+

+

Glycosides

-

-

-

+

+

Steroids

-

-

-

-

-

Flavonoids

-

-

-

+

-

Saponins

-

-

-

-

-

Fixed oils and fats

-

-

-

-

-

Tannins

-

-

-

+

+

Proteins and amino acids

-

-

-

-

+

Mucilage

-

-

-

-

+

 


 

Table 3: Percent extractives of successive extracts of Thespesia populnea stem bark

Solvent

Extractive values (% w/w)

Pet. Ether

2.52

Chloroform

4.18

Ethyl acetate

2.72

Ethanol

12.50

Water

10.84

 

RESULT AND DISCUSSION:

Macroscopical characters:

The bark of Thespesia populnea were varies from 5-10 cm long, 3-5 cm width and 0.6-0.10 cm thick. The outer surfaces were dull brown or grey in color, rough due to longitudinal and transverse crack and fissure were seen. Exfoliation of the outer bark was seen in some place. Inner surface were striated and pale yellowish in color. The fractures were short and fibrous. The odour and taste were aromatic, characteristic and slightly bitter. A yellow exudates was oozed out from the fractured surface probably mucilage

 

Microscopical characters:

Transverse section of the bark showed the following distinct characters:

 

Periderm: The stem of the epidermis were replaced by a broad zone of periderm. The periderm comprises of five to eight layers of suberized cork cells and three or four layers of thin walled phelloderm cells. Fissures of various shapes and wide lenticels were seen in the periderm.

 

Cortex: The periderm is followed by a narrow cortical zone which consists of several layers of tangential oblong compact parenchyma cells.

 

Phloem: It consists of wide secondary phloem comprises of radial series of phloem elements alternating with tangential blocks of phloem fibers. Funnel shaped dilating rays in between the radial cones of phloem. This zone is differentiated into outer collapsed phloem and inner intact phloem. The collapsed phloem has wide, funnel shaped, dilating rays alternating with radially extended, conical phloem fibers and crushed sieve elements. The dilating rays have tangential rows of narrowly rectangular parenchyma cells. The radial, conical segments of phloem have thick bands of phloem fibers alternating with crushed phloem elements (Fig: 1).

 

TLS view of the phloem: In tangential longitudinal section the structure of the phloem rays and sieve elements were seen. The phloem rays are non storied. They are wide and very high. The rays range from uniseriate to multiseriate. The multiseriate rays are three or four cells thick. There are homocellular consisting of only one type of cells namely polygonal, thin walled cells. The rays range in height from 140-750 µm with average

 

of 490 µm. The uniseriate and biseriate rays are 90 to 170 µm within on average 130 µm. Mucilage cavities are seen frequently in the phloem zone. The sieve tube members are long and narrow. They have simple, oblique sieve plate. The phloem parenchyma cells are fusiform type and they appear to be storied. Calcium oxalate druses are abundant in the medullary ray cells. They occur mostly in singles (Fig: 2,3).

 

For identification and evaluation of plant drugs by pharmacognostical studies is still more reliable, accurate and inexpensive17. The macroscopical studies of bark revealed the presence of characteristic aromatic odour, color, taste and the fracture surface. The microscopical study indicated the presence of a typical arrangement of phloem tissues, mucilage cavity, medullary rays and the absence of sclerides, etc may be useful for their identification.

 

In physiochemical studies of various parameters established, like various ashes content which showed the presence of inorganic salts by naturally occurring or adhering to it, or deliberately added to it as a form of adulteration. These values are important quantitative standards. The various extractive values obtained by results showed higher yield in ethanolic extract14.

 

The extracts obtained by exhausting plant materials with specific solvents are indicative of approximate measures of their chemical constituents extracted with those solvents from a specific amount of air-dried plant material. This parameter is employed for materials for which as yet no suitable chemical or biological assay exists. The results also showed higher extractive values in hot extraction, indicating the effect of elevated temperature on extraction. In all methods alcohol yielded higher extractives18.

 

The plant material was subjected to preliminary phytochemical screening involving successive solvent extraction by different solvents in order of increasing polarity to obtain diverse polar and non polar phytoconstituents possessing different solubility pattern, followed by various chemical tests for qualitative detection of various chemical constituents. The percent extractives in different solvents indicate the quantity and nature of constituents in the extract19.

 

CONCLUSION:

The present investigation it can be concluded that the pharmacognostical study of Thespesia populnea bark yielded a qualitative and quantitative parameters or standards that can serve as an important possible sources of information to ascertain the identity and to determine the quality and purity of the plant material.

 

These information will also be helpful to differentiate Thespesia populnea from the closely related other species and varieties of Thespesia.

 

FIG-3: Crystal distribution in TLS of Thespesia populnea bark.

 

REFERENCE:

1.        Anonymous, 1995. The Wealth of India. Publication and information Directorate (CSIR), New Delhi, 223-275.

2.        Sathyanarayana, T., Sarita, T., Balaji, M., Ramesh, A., Boini., M.K. Antihyperglycemic and hypoglycemic effect of Thespesia populnea fruits in normal and alloxan–induced diabetes in rabbits. Saudi Pharmaceutical Journal. 2004; 12: 107-111.

3.        Ilavarasan, R., Vasudevan, M., Anbazhagan S., Venkataraman S. Antioxidant activity of Thespesia Populnea bark extracts against carbon tetrachloride induced liver injury in rats. J.Ethanopharmacology. 2003; 87: 2-3: 227-230.

4.        Ilavarasan, R., Vasudevan, M., Anbazhagan S., Venkataraman S., Sridher, S.K. Hepatoprotective activity of Thespesia Populnea bark extracts against carbon tetrachloride-induced liver injury in rats. Natural Product Sciences. 2003; 9: 83-86.

5.        Shirwaikar A., Kumar A.V., Krishnanand B.R., Sreenivasan K.K. Chemical investigation and antiheptotoxic activity of Thespesia Populnea. International journal of Pharmacognosy. 1995; 33: 305-310.

6.        Mani vasudevan M., Kumar Kishore Gunman, Milind Parle. Journal of ethnopharmacology. 2007; 109: 264-270.

7.        Akila A., Rani K. Biosynthesis of gossypol in Thespesia Populnea. Phytochemistry. 1993; 335-340.

8.        Ghosh K., Bhattacharya T.K. Preliminary study on the anti-implantation activity of compounds from the extract of seeds of Thespesia Populnea. Indian Journal of Pharmacology. 2004; 36: 335-340.

9.        Murthy, R.S.R., Basu, D.K., Murti, V.V.S. Antifertility activity of (+) gossypol. Current Sciences. 1981; 50: 64-66.

10.     Qian S., Wang Z. Gossypol a potential antifertility agent for males. Annual review of pharmacology Toxicology. 1984; 85: 329-360.

11.     Johnson, J.I., Gandidasan, R., Murugesan, R. Cytotoxicity and superoxide anion generation by some natural occuring quinins. Free Radical Biology and Medicine. 1999; 26: 1072-1078.

12.     Daniel, M. Medicinal plants-Chemistry and Properties. Science publishers. 2006; 184.

13.     Khandelwal KR. Practical Pharmacognosy: Techniques and Experiments. 12th ed. Pune : Nirali Prakashan; 2004: 9,149.

14.     Kokate CK. Practical Pharmacognosy. 4th Ed. New Delhi: Vallabh Prakashan; 2005; 7, 14, 107.

15.     Anonymous. Indian Pharmacopoeia. Vol II. 4th Ed. New Delhi: Controller of Publications, Government of India; 1996.

16.     Evans WC. Trease and Evans Pharmacognosy. 15th ed. Edinburgh: W.B. Saunders; 2002.

17.     Anonymous. Quality Control Methods for Medicinal Plant Materials (An Authorized publication of World Health Organisation, Geneva). New Delhi: A.I.T.B.S. Publishers and Distributors (Regd.); 2002.

18.     Mukherjee PK. Quality Control of Herbal Drugs: An approach to evaluation of botanicals. 1st ed. New Delhi: Business Horizons; 2002.

19.     Kokate CK., Purohit AP., Gokhale SB., Pharmacognosy. 34th ed. Pune: Nirali Prakashan; 2006.

20.     Rastogi, RP., Mehrotra, BN., Compendium of indian medicinal Plants. Lucknow: CDRI; and New Delhi; Publication and information Directorate; Vol. 5; 1979: 846.

21.     Wallis TE. Text Book of Pharmacognosy. 5th Ed. New Delhi: CBS Publishers and Distributers; 1985.

 

Received on 07.06.2009

Accepted on 14.08.2009        

© A&V Publication all right reserved

Research Journal of Pharmacognosy  and Phytochemistry. 1(2): Sept. - Oct. 2009, 128-131