INTRODUCTION:

Erythrina stricta Roxb belongs to the family Fabaceae. It is an armed deciduous tree. The tree is found in the plains and found up to an altitude of 1000m. The tree is 15-20 m tall, with apically stellate branchlets, pubescent, basically glaberescent densely prickled.

Leaves:

10-30 cm long trifoliate leaflets, rhomboid-ovate 8-12 in number which are 9-20 cm, thin coriaceous, glaberescent, base deltoid or truncate, margin entire, apex sub acute petiole 10-13 cm, petiolate 0.6-1cm.

Racemes:

10cm long, peduncle 4-6cm, bracts ovate; bracteole-3mm, pedicels 3 in a cluster 8mm long.

Flowers:

5cm x 2 cm. Calyx: Spathaceous, 1.5 cm, entire at the tip, split halfway down, erect, glaberescent. Corolla: deep red; standard oblong – lanceolate, 5x2 cm; wing obovate, 5.5x3 mm; keels – ovate 2x0.7 cm. Staminal sheath 2.5 cm; anthers 2-3 mm, ovary 2 cm, pubescent; style 1.5 cm, sub erect.

Fruit pod:

Brownish 10 cm long; 3-4 seeded.

It is widely distributed in the Asian and South East Asian countries like India, Nepal, Burma, Thailand, Vietnam and China^[1,
2]. The plant is used in traditional medicine for the treatment of biliousness, rheumatism, asthma, leprosy, epilepsy, fever, antidote to poison^[3,4]. Pharmacological studies reveal that anti inflammatory activity^[5], anti cataract activity^[6], cardio protective activity^[7], anti microbial activity^[8], anti urolithic activity^[9], in vitro xanthine oxidase inhibition^[10], anti plasmodial activity, anti mycobacterial activity, cytotoxicity studies^[11] and anti hyperuricemia^[12]. There was no data on Pharmacognostical studies of any part of the tree. Therefore in this study Erythrina stricta bark has been subjected to Pharmacognostical investigation.

MATERIALS AND METHODS:

The bark of Erythrina stricta was collected in September 2014 from Gummidipundi, Tamil Nadu India. The plant was identified and authenticated by Prof. Dr. P. Jayaraman, Director, Institute of Herbal Botany, Plant Anatomy Research Center, Tambaram. The plant material was certified as Erythrina stricta of family Fabaceae and certificate number is (PARC/2014/2054). A voucher specimen (05/PCOG/2015) was deposited in the Department of Pharmacognosy College of Pharmacy Madras Medical College Chennai for future reference.

Macroscopic features:

The color, odor, taste, shape, size, and surface of the bark were studied.

Microscopic features:^{[13, 14]}

Transverse section of the bark was taken using a microtome. For this fresh bark material was fixed in fixing agent (formalin-5 ml + acetic acid-5 ml + 70 % ethyl alcohol-90ml). After 24h of fixation the specimen was dehydrated with graded series of tertiary butyl alcohol. Then specimens were cast into paraffin blocks. The paraffin embedded specimens were sectioned with the help of rotary microtome. The thickness of the sections was 10-12 μm. Dewaxing of the sections was done by customary procedure. The sections were stained with toluidine blue.

Histochemical Studies:^[^15]

The bark sections were stained using specific reagents (N/50 iodine, phloroglucinol and concentrated hydrochloric acid, ferric chloride and Dragendroff’s reagent) to observe and locate starch, lignin, tannin and alkaloid respectively. The stained sections were then washed in water to remove the excess stain and observed under a microscope.

Powder Microscopy:^[^16]

The dried stem bark was powdered and studied under microscope. Different staining reagents (such as iodine for detection of starch grains, phloroglucinol for detection of lignified components and glycerin in water for calcium oxalate crystals) were used. Powdered materials of bark were cleared with NaOH and mounted in glycerine medium as such or after staining and observed through microscope.

Linear measurements:^[^17]

A little quantity of powdered sample was mounted in N/50 Iodine and glycerin in water for the measurement of diameter of starch grains and length and width of calcium oxalate crystals respectively. It was measured using eye piece micrometer.

Physicochemical Constants:^{[18, 19]}

In this study, air dried material was used for quantitative determination of physiochemical values like loss on drying, total ash, acid insoluble ash, water soluble ash, sulphated ash value and extractive values were determined as per standard methods.

RESULTS AND DISCUSSION:

Macroscopical Features:

The following characteristic features of the bark was seen : (figure 1)

Shape : Single Quill

Size : 13-15cm long

3-4 cm broad

Surface: Lenticels are present on the outer surface;

dense sharp prickles are present and vertical

oblong fissures

Fracture: Fibrous

Color : Brown

Taste : Bitter

Odour : Odourless

Figure 1 Bark of Erythrina stricta

Microscopic features:

The surface of the bark is pale green, smooth with narrow, vertically long oblong fissure. The cortical zone is narrow with scattered masses of fibers. The remaining major part of the bark includes the secondary phloem.

Periderm:

The periderm is 150µm thick. It consists of compact radial files of tabular, suberised, phellem cells. Phelloderm is not evident. This is followed by a narrow cortical zone with scattered masses of fibers (Figure 2).

Secondary phloem:

The secondary phloem forms the major part of the bark. It is differentiated into outer side of collapsed phloem and narrow zone of inner non collapsed phloem. The collapsed phloem exhibits, thin dark, tangential lines of crushed sieve elements, dilated phloem parenchyma cells and dilated phloem rays (Figure 3).

Non collapsed phloem:

The intact phloem elements are seen in narrow radial bands alternating with lateral phloem rays. The non collapsed phloem consists of rectangular, fairly thick walled wide sieve elements and prominent companion cells located on the lateral sides of the sieve elements. The sieve elements are upto 50µm in diameter (Figure 4).

Sieve elements:

The sieve elements are distinctly visible in tangential sections. They are vertically oblong and thin walled. They usually occur in horizontal files. The sieve elements are 150 to 220µm in length (Figure 5).

Calcium oxalate crystals:

Calcium oxalate crystals are abundant in the parenchyma cells which surrounds the sclerenchyma bundles. The crystals are prismatic type. Calcium oxalate crystals are seen in compact vertical rows of the phloem (Figure 6)

Histochemical studies:

The histochemical studies of Erythrina stricta bark with different chemical reagents are summarized in Table 1.

Table 1. Histochemical studies of Erythrina stricta bark

S. No	Reagents	Nature of change	Histology	Test for
1	Phloroglucinol +HCl	Pink	Sclerides	Lignin
2	N/50 Iodine solution	Bluish black	Cortex	Starch
3	Dilute Ferric chloride	-	-	Tannin
4	Dragendroff’s reagent	Orange	Phloem rays	Alkaloid

Powder microscopy:

Powder microscopy of Erythrina stricta bark indicates the presence of parenchyma cells, sclerides, starch grains, calcium oxalate crystals (Figure 7).

Figure 7 Powder microscopy

Linear measurements:

Linear measurement of starch grains and calcium oxalate crystals in Erythrina stricta bark are summarized in Table 2 and Table 3 respectively.

Table 2. Linear measurements of starch grains

Dimension	Minimum (μm)	Average (μm)	Maximum (μm)
Diameter	16.25	20.67	40.62

Table 3. Linear measurements of calcium oxalate crystals

Dimension	Minimum (μm)	Average (μm)	Maximum (μm)
Length	32.5	47.92	65
Width	16.25	28.43	48.75

Physiochemical constants:

In this study, various physicochemical parameters like loss on drying, total ash, acid insoluble ash, water soluble ash, sulphated ash and extractive values were determined in triplicate and are mentioned in Table 4.

Table 4. Physicochemical constants of the bark of Erythrina stricta

S.no	Parameters	Percentage (%W/W)
I	Ash value
1	Total ash	10.57 ± 0.56
2	Acid insoluble ash	2.30 ± 0.67
3	Water soluble ash	7.45 ± 0.87
4	Sulphated ash	12.61 ± 0.85
II	Extractive value
1	Water soluble extractive	3.31 ± 0.56
2	Alcohol soluble extractive	5.20 ± 0.78
3	Ether soluble(non-volatile) extractive	6.12 ± 0.41
4	Ether soluble(volatile) extractive	3.23 ± 0.16
III	Loss on drying	5.97 ± 0.67
IV	Swelling index	<100
V	Foaming index	NIL

Values are expressed as a mean ± SD (n=3)

The foaming index was <100 and the swelling index were nil indicating the absence of saponin and mucilage.

CONCLUSION:

The present study was undertaken to lay down standards which could be useful in authenticating this plant. The macroscopic, microscopic and physico-chemical standards of Erythrina stricta bark will be helpful in establishing parameters for standardization and sample identification.

REFERENCE:

1. Matthew K.M. The Flora of the Tamil Nadu, Carnatic Volume I, The Rapinat Herbarium St. Joseph’s College, Tiruchirappalli. The Diocesan Press, Madras, India, 1983.

2. Manjunath B.K, Krishna V and Pullaiah T. Flora of Davangere District Karnataka, India. Regency Publications, New Delhi, India, 2004, 137.

3. Dr.Nadkarni K.M. Indian Materia Medica, Volume 1. Popular Prakashan, Bombay, India, 2009, 509.

4. Khare C.P. Indian Medicinal Plants. Springer, New York, 2007, 246.

5. Subhashini N, Purnima S, Amutha Aiswariya Devi J, Thanga Thirupathy A. Anti inflammatory activity of Erythrina stricta in albino rats. International Journal of Pharm Tech Research. 3(2); 2011:1014-1018.

6. Umamaheshwari M, Kuppusamy A, Subdhradevi V, Thrimalaisamy AS, Nethu M. Anti cataract activity of leaves of Erythrina stricta on naphthalene induced catractogenisis in rats. Bangladesh Journal of Pharmacology. 5; 2010:77-81.

7. Kuppusamy A, Subdhradevi V, Christy J, John H, Sherin D, Athiyappan G. Cardio protective activity of leaves of Erythrina stricta on isoproterenol – induced myocardial infaraction in rats. Bangladesh Journal of Pharmacology. 5; 2011:1-4.

8. Hussain MM, Dastagir MG, Mausam Billah AHM, Mizanur Rahaman and Ismail MD. Anti microbial activity of n- hexane and ethyl actate extract of Erythrina stricta Roxb. Bangladesh Journal of Microbiology. 27(2); 2010:65-66.

9. Kamboj P and Nath A. Anti-urolithiatic screening of aerial parts of Erythrina stricta. Pharmaceutical biology. 50(5); 2012: 601.

10. Umamaheshwari M, Kuppusamy A, Remya RA, Siva Shanmugam AT. In vitro anti xanthine oxidase activity of the fractions of Erythrina stricta. Journal of Ethnopharmacology. 124(3); 2009:646-648.

11. Rukachaisirikul T, Saeekee A, Tharibun C, Swadarut W and Suksamaran A. Biological activities of the chemical constituents of Erythrina stricta and Erythrina subumbrans. Archives of of Pharmacal Research. 30(11); 2007:1398-1403.

12. Remya RA, Joseph S, Mathews MS, Soniya S. Effect of the fractions of Erythrina stricta leaf extract on serum urate levels and Xo/Xdh activities in oxonate induced hyperuricaemic mice. Journal of Applied Pharmaceutical Science. 2(2); 2012: 89-94.

13. Sass JE. Elements of botanical microtechnique. Mc Graw Hill book Co, New York. 1940.

14. Johansen DA. Plant microtechnique. Mc Graw Hill book Co, New York. 523.

15. Krishnamurthy KV. Methods of histochemistry. Vishwanath Printers and Publishers, Chennai. 1998, 5-10.

16. Kokate CK. Practical Pharmacognosy. 4th Ed. Vallabh Prakashan, New Delhi. 2002;123-124.

17. Divakar C. Plant drug evaluation. 2nd Ed. CD Remedies, Kerala (Ernakulam). 2002; 49-50.

18. The Ayurvedic Pharmacopoeia of India.: The controller of publications, New Delhi. 2001; 143.

19. World Health Organisation. Quality Control Methods for Medicinal Plant Materials, WHO Geneva Switzerland. Materials. 1998; 128.

Received on 15.05.2015 Modified on 15.06.2015

Res. J. Pharmacognosy & Phytochem. 7(3): July-Sept. 2015; Page 141-145

DOI: 10.5958/0975-4385.2015.00025.4