An Identity Based Pharmacognostical Profile of Sisymbrium officinale

K. Rajendran², Bahlul Z.S. Awen², Eiman Molod Aboalied Sowan² and R. Vijaya Bharathi¹

¹Department of Pharmacognosy, Madras Medical College, Chennai, India.

²Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, Al-Jabal Al- Gharbi University, Al- Zawia, Libya.

ABSTRACT:

This article presents an identity based pharmacognostical study of the leaf and stem of Sisymbrium officinale (Brassicaceae). Morphoanatomy of the leaf were studied to aid pharmacognostical and taxonomical identification, using light and confocal microscopy. The morphological, anatomical parameters and Physico-chemical profile presented in this paper may be proposed as parameters to establish the authenticity of S. officinale and can possibly help to differentiate the drug from its other related species.

KEYWORDS: Sisymbrium officinale, Micromorphology, Physico-chemical

INTRODUCTION:

Sisymbrium officinale (Brassicaceae) is an annual or biennial herb and up to 40 cm high, leaves are oppositely cleft almost to midrib and flowers are yellow, pink or white in colour. The whole plant is used as diuretic, expectorant, cardiotonic, laxative and stomachic. This plant was at one time known as the 'singer's plant' because of its use in treating loss of the voice. A strong infusion of the whole plant has been used in the treatment of throat complaints¹.

Despite the numerous medicinal uses attributed to this plant, there are no pharmacognostical reports on the leaf of this plant. Hence, the present investigation deals with the identity based pharmacognostical evaluation of the aerial part of Sisymbrium officinale. The study includes morphological and anatomical evaluation and preliminary phytochemical screening of the different extracts the plant.

MATERIALS AND METHODS:

Plant Material:

Fresh plant Sisymbrium officinale was collected from Al-Zawia, Libya in the month of March 2010. The plant was identified, confirmed and authenticated by a Taxonomist and herbarium specimen bearing voucher No. PP. 102 has been deposited in the Department of Pharmacognosy, College of Pharmacy, Al-Jabal Al- Gharbi University, Al-Zawia, Libya.

Macroscopical and microscopical studies:

The macroscopy and microscopy of the plant was studied according to the method of Brain and Turner². For the microscopical studies, the cross sections were prepared and stained as per the procedure of Johansen³ and the quantitative microscopy was studied as per the procedure given by Wallis⁴. The powder analysis has been carried out according to the method of Brain and Turner⁵. Leaf constants such as vein islet number, veinlet termination number, palisade ratio, stomatal number and stomatal index were studied according to the method of Evans⁶.

Physico-chemical constants:

The ash values, extractive values, loss on drying, foaming index, swelling index and volatile oil content were performed according to the official methods prescribed in Indian Pharmacopoeia⁷. Fluorescence analysis was carried out according to the method of Chase and Pratt⁸ and Kokoski et al⁹.

Preliminary phytochemical Studies:

Preliminary phytochemical Screening was carried out by using standard procedures described by Harborne¹⁰.

RESULTS AND DISCUSSION:

Macrosopy

The plant is an annual or biennial herb and grows up to 40 cm in height. Leaves are oppositely cleft almost to midrib, alternate, divided into several, irregularly toothed, narrow segments on each side and larger angular or roundish terminal segment, middle and upper leaves smaller, short-stalked or stalkless, less divided or with no lobes along the side. The basal and lower alternate leaves are are pinnatifid with several pairs of narrow lobes. The upper leaves are divided into 3 lobes (a terminal lobe and 2 lateral ones) or lanceolate-ovate in shape. The upper surfaces of these leaves are dull green and hairless; their margins are irregularly dentate or shallowly cleft. The basal and lower leaves have long petioles, while the upper leaves have short petioles or they are sessile.

Fig 1: T.S. of Sisymbrium officinale leaf through midrib with lamina

Abs- Abaxial side; Ads-Adaxial side; Ep- Epidermis; Ph- phloem; Pm- palisade mesophyll; X- xylem; Tu- Trichome unicellular; Tm- Trichome multicellular; Co- Collenchyma;

Cp- Cortical parenchyma; Pg- Peltate gland; Sp- Spongy parenchyma; Fv- Fibrovascular bundle; Fi- Fibres; V- Vessel

Microscopical studies:

T.S of leaf (Fig. 1)

The leaf is dorsiventral with thin lamina and prominent midrib. The epidermal layer consists of single layered rectangular cells on both the sides with a very thick cuticle. The mesophyll is differentiated into palisade and spongy parenchyma. The palisade cells are 2 layered ,vertically oblong compact layer of cells and does not form continuous band throughout as it is absent above the vascular bundle as in the midrib. The spongy parenchyma cells are 2-4 layered, the cells are small. Because of the prominent fibrovascular bundles, the abaxial side of midrib shows three frequent projections, which are embedded in both the sides of the vascular bundle and other one is seen below. The fibrovascular bundles are very distinct, in which 2-3 layer of vessels arranged on the group of fibres and forming the bowl shape. The vascular bundle is single and collateral. Phloem occurs as a thin sheath beneath the xylem. Calcium oxlate crystals of any type are absent. In the lateral and upper portion of the vascular bundle occurs a thin layer of dilated parenchyma cells. The adaxial side extension is wide with large parenchyma cells. A patch of collenchyma is found above the lower epidermis.

Trichomes of the epidermal layer are common on the lamina. The covering trichomes are of two types, some are unicellular non-glandular or covering type others multicellular covering type. Multicelluar covering trichomes are 2-4 celled, thin walled and occur either on the lower side or on the upper side of the leaf. The unicellular covering trichomes are short, thick, warty, uniformly narrow and tapering at the tip. Peltate glandular trichomes without stalk are seen rarely on abaxial side. The glands are 12 to 15 celled, yellowish brown in color and horizontal plate of radiating cells.

Tu- Trichome unicellular; Tm- Trichome multicellular; Me- Mesophyll; As- Anisocytic stomata

T.S. of Young Stem (Fig. 3):

Transverse section of the stem is more or less circular. There is intact, thick, two epidermal layers with squarish cells and thick cuticle. Cortex shows loosely arranged 4-6 layers of parenchyma cells. Single or group of non-lignified fibres are seen in cortex region. The vascular bundles are collateral and group of lignified pericyclic fibres crown the phloem on its outer side. The vessels are circular, thick walled and are in long or short radial multiples. Some vessels are big, oval shape with thick lignified walls. Pith is large and is made of thin walled, big polygonal parenchyma with intercellular space.

Powder microscopy:

Leaf (Fig. 2)

The trichomes are of two types, some are unicellular non-glandular or covering type others multicellular covering type. Multicelluar covering trichomes are 2-4 celled, thin walled and occur either on the lower side or on the upper side of the leaf. The unicellular covering trichomes are short, thick, warty, uniformly narrow and tapering at the tip. Anisocytic or cruciferous type of stomata meaning thereby that stomal pore is surrounded by 3 or 4 wavy walled unequal subsidiary cells of which one is invariably smaller than the other two. Fragment portion of mesophyll shows the palisade zone, two layers of vertically oblong compact layer of cells and the spongy parenchymatous cells are 3-4 layered.

Ep- Epidermis; C-Cortex; Pf- Pericyclic fibres; Ph- Phloem; Pi- Pith; Fn- Fibre non-lignified; V- Vessel

Stem (Fig. 4)

Non-ignified fibres of uniform thickness, slender and long appear as group. Fibres are often seen associated with vessels. Vessels are large, reticulate and annular thickening with numerous bordered pits.

Leaf constants:

The leaf constants viz; the vein islet number, veinlet termination number, palisade ratio, stomatal number and stomatal index are presented in Table 1.

Table 1. Leaf constants of S. officinale

S. No.	Leaf constants	Values
1.	Vein islet number	12 -15 / sq.mm
2.	Veinlet Termination Number	11 -19 /sq.mm
3.	Stomatal Index a) Adaxial b) Abaxial	32.9 35.4
4.	Stomatal number a) Adaxial b) Abaxial	242.6/ sq.mm 281.2/ sq.mm
5.	Palisade ratio	6-10

Physicochemical parameters:

The physiochemical parameters are mainly used in judging the purity and the quality of the drug (Table 2). Ash values give an idea of the earthy matter or inorganic composition or other impurities present along with the drug. Extractive values give an idea about the chemical constituents present in the drug as well as useful in the detection of exhausted or adulterated drugs. The result suggests that the powdered plant have high water soluble extractive value as compared to other extractive values. The loss on drying reveals the percentage of moisture present in the drug. The foaming index and swelling index also studied. The fluorescence analysis of powdered drug and extracts was studied in both UV and daylight (Table 3).

Table 2. Physico-chemical constants S. officinale

S. no	Parameters	Values
I	Ash values
1	Total ash	7.40 % w/w
2	Acid Insoluble Ash	0.046 % w/w
3	Water Soluble Ash	6.92 % w/w
4	Sulphated Ash	8.64 % w/w
II	Extractive values
5	Alcohol soluble Extractive	4.7 % w/w
6	Water soluble Extractive	12 % w/w
7	Non- volatile Ether soluble Extractive	2.12 % w/w
III	Other parameters
9	Mucilage content	4.06 %w/w
10	Loss on drying	2.14 % w/w
11	Swelling index	4 % w/w
12	Foaming Index	142.85
13	Volatile oil content	0.5 % v/w

Preliminary phytochemical screening:

Preliminary phytochemical screening of the plant extracts showed the presence of terpenoids, carbohydrates, proteins, steroids, alkaloids and volatile oils (Table 4).

CONCLUSION:

As there is no pharmacognostic/anatomical work on record for this much valued traditional drug, the present work was taken up with a view to lay down standards which could be useful to detect the authenticity of this medicinally useful plant. Macro and micro morphological standards and physic-chemical profile discussed can be considered as identifying parameters to substantiate and authenticate the plant Sisymbrium officinale.

Table 3. Fluorescence analysis of S. officinale powder

S. no	Treatment	Day light	Short UV (254 nm)	Long UV (365 nm)
1	Powder	Green	Greenish blue	Greenish blue
2	Powder + water	Yellowish green	Greenish blue	Greenish blue
3	Powder +1N HCl	Slight reddish brown	Blue	Blue
4	Powder+1N H₂SO₄	Yellow	Blue	Dark blue
5	Powder +1N HNO₃	Brown	Light blue	Greenish blue
6	Powder+Acetic acid	Yellow	Light green	Light green
7	Powder + 1N NaOH	Dark yellowish green	Dark green	Dark green
8	Powder +1N KOH	Green	Dark green	Dark green
9	Powder+1NAlc. NaOH	Dark yellow	Green	Dark greenish blue
10	Powder +1NAlc. KOH	Greenish yellow	Greenish blue	Bright Sky blue
11	Powder + Ammonia	Light yellowish green	Light bluish yellow	Dark bluish yellow
12	Powder + Iodine	Light yellow	Greenish	Greenish
13	Powder + FeCl₃	Greenish brown	Greenish blue	Greenish blue
14	Powder + Ethanol	Bright green	Blue	Bluish green

Table 4. Preliminary Phytochemical Screening of S. officinale

Test	Hexane	Benzene	Chloroform	Ethyl acetate	Ethanol	Water
Carbohydrates	-	-	-	-	+	+
Phytosterols	+	+	+	-	-	-
Terpenes	+	+	+	-	-	-
Volatile oil	+	-	-	-	-	-
Lipids and fats	-	-	-	-	-	-
Saponins	-	-	-	-	+	+
Alkaloids	+	+	-	-	-	-
Phenolic compounds and tannins	-	-	-	-	-	-
Proteins and amino acids	-	-	-	-	+	+
Flavanoids	-	-	-	+	+	-
Gums and Mucilage	-	-	-	-	-	+

+ denotes the presence of the respective class of compounds, - denotes the absence of the respective class of compounds