Pharmacognostical Studies on Root of Tribulus terrestris

Mamdouh N. Samy¹*, Mokhtar M. Bishr², Ahmed A. Ahmed³, Hanaa M. Sayed⁴ and Mohamed S. Kamel¹

¹Department of Pharmacognosy, Faculty of Pharmacy, Minia University, Minia 61519, Egypt.

²Research and Development Department, Mepaco Company, Cairo, 11361, Egypt.

³Department of Organic Chemistry, Faculty of Science, Minia University, Minia 61519, Egypt.

⁴Department of Pharmacognosy, Faculty of Pharmacy, Assuit University, Assuit 71526, Egypt.

ABSTRACT:

Tribulus terrestris L. is an annual, prostrate, branched herb of the Zygophyllaceae family. In traditional medicine, hot water extract of the root is taken orally as an aphrodisiac. Therefore, in this context the detailed pharmacognostic study of root has been carried out with the aim to establish its pharmacognostical standards. The microscopical studies of root revealed the presence of cluster crystals, starch granules, lignified fibers, pitted wood parenchyma and pitted xylem vessel.

KEYWORDS: Tribulus terrestris, Zygophyllaceae, pharmacognostical study, root.

INTRODUCTION:

The genus Tribulus belongs to family Zygophyllaceae comprises approximately 25 species which grow as prostrate hairy herbs in tropical and warm regions^1,2. Tribulus terrestris L. (Zygophyllaceae) (Fig. 1) is commonly known as devil's thorn, cat head, puncture vine, goat head and caltrop³. It is a herbaceous, annual, prostrate or semierect, diffusely branched herb⁴. The stems have monopodial branching and carry opposite compound paripinnate leaves and yellow simple flowers. The fruit is schizocarpic. It is native in dry and sandy districts in South Europe to Central Asia and in tropical and South Africa⁵, growing in India, other warm countries such as Ceylon⁶, desert plains, waste ground, weed of cultivation and Mediterranean region¹. It is used in folk medicine to increase spermatogenesis, for treatment of eye troubles, edema, abdominal distension, leucorrhea and impotence, as aphrodisiac, galactagogue, anti-inflammatory, antidiarrheal and diuretic⁴.

Fig. 1: Photo of Tribulus terrestris L.

MATERIALS AND METHODS:

Plant material:

The root of T. terrestris was collected during the flowering and fruiting stage in October 2004 from the green areas of Minia University Campus, Minia, Egypt. A voucher specimen of the plant is deposited in the Herbarium of Faculty of Pharmacy, Minia University, Egypt (Minia-04-Mar-TT).

Microscopic studies:

T. S. and powder of the roots were used for observation of various microscopic features.

RESULTS AND DISCUSSION:

Macroscopical characters:

The root (Fig. 2) is 7 to 15 cm tap root. There are lateral rootlets arise at each node and showing a yellowish white colour.

Fig. 2: photo of the root

Microscopical characters:

A transverse section in the root (Fig. 3 and 4) is nearly circular or slightly irregular in outline. It shows a comparatively wide bark occupying about one third of the radius and surrounding wide wood cylinder representing the main part of the root.

The cork:

It consists of narrow zone of 3 to 5 layers of tangentially elongated, tabular, thin walled cells and being about 50 to 150 m in width and 10 to 40 m in length and 20 to 40 m in surface dimensions.

Fig. 3: Photos of T. S. in root

Fig. 4: Sketch of T. S. in root

The phelloderm: (Secondary cortex)

It is formed of several layers of alternating groups of thick-walled parenchmatous cells with thin-walled parenchmatous cells containing scattered cluster crystals of calcium oxalate measuring about 30 to 40 m in diameter and abundant starch granules; the starch granules are mainly simple, muller-shaped to somewhat spherical with slightly eccentric, sometimes centric hilum measuring from 5 to 15 µ in diameter.

The primary cortex:

It is formed of few layers of thin-walled parenchmatous cells containing scattered cluster crystals of calcium oxalate measuring about 30 to 40 m in diameter and abundant starch granules; the starch granules are mainly simple, muller-shaped to somewhat spherical with slightly eccentric, sometimes centric hilum measuring from 5 to 15 µ in diameter.

The phloem:

It is formed of a narrow ring of secondary phloem surrounding the xylem; consisting of shining, thin-walled, soft and cellulosic elements of sieve tubes, companion cells and phloem parenchyma. The phloem parenchyma containing starch granules which are mainly simple, muller-shaped to somewhat spherical with slightly eccentric, sometimes centric hilum measuring from 5 to 15 µ in diameter.

The cambium:

Cambial zone is formed of about 4 to 6 rows of thin-walled, cellulosic cells which are tangentially elongated and radially arranged.

The xylem:

It is a wide cylinder of lignified pitted elements surrounded by fibers. Some xyllary elements are lignified and the remaining is thickened, non-lignified elements. The vessels occur mainly solitary but sometimes being in radial rows of 2 to 4. They are wide, lignified, showing simple pits with rounded or oval opening; being about 60 to 120 m in diameter. The wood fibersare abundant, having usually straight regular or slightly irregular outline, usually with wide lumens, acute ends sometimes forked and thick irregular to somewhat dentate lignified walls, being about 300 to 850 m in length and about 20 to 30 m in diameter. The xylem region is traversed by numerous, narrow medullary rays which are uniseriate or biseriate to triseriate; the cells are mostly rectangular, non-lignified, usually radially elongated containing starch granules.

The powder of the root: (Fig. 5 and 6)

The powder of the root is yellowish white in color with faint characteristic odor and bitter taste. The main diagnostic microscopic elements were:

1. Fragment of cork cells in surface view.

2. Cluster crystals of calcium oxalate.

3. Fragment of lignified wood fibers. The fibers are long, having thick, lignified walls.

4. Starch granules.

5. Fragment of lignified pitted wood parenchyma.

6. Fragment of lignified xylem vessels with pitted thickening.

Fig. 6: Sketch of powdered root

CONCLUSION:

In conclusion, the microscopic studies on the root of Tribulus terrestris L. can assist as a relevant source of information and contribute towards the standards to dispose the quality and identity of this plant in future exploration.

REFERENCES:

1. Boulous L., 2000. Flora of Egypt. Vol. 2.Cairo, Egypt: Al Hadara Publishing, pp: 26-31.

2. Tackholm V., 1974. Students' Flora of Egypt. 2nd ed. Beirut: Cairo University Cooperating Printing Co., pp: 311-313.

3. Quattrocchi U, 2000. CRC world Dictionary of Plant Names. Vol. IV. Boca Raton, London, New York, Washington, D. C: CRC press, pp: 2708.

4. Ross IA, 2001. Medicinal Plants of the World. Chemical Constituents, Traditional and Modern Uses. Vol. II, Humana Press Inc, pp: 411-426.

5. Rendle AB, 1959. The Classification of Flowering Plants. Vol. II, Cambridge: the University Press, pp: 280.

6. Chopra RN, 1933. Indigenous Drugs of India. 20 British Indian Street, Calcutta: The Art Press, pp:408..

Received on 12.10.2013

Modified on 27.11.2013

Accepted on 02.12.2013

Research Journal of Pharmacognosy and Phytochemistry. 5(6): November –December 2013, 280-283