Pharmacognostical Analysis of the Leaves of Important Nervine Medicinal Plant: Strychnos Nux-Vomica L

Geographical Distribution

Strychnos Nux-Vomica L. tree distribution includes Ceylon, India, East Bengal, Burma, Thailand, Laos, Cambodia and S.Vietnam [5]. The wild tree is plentiful throughout tropical India [6, 7] upto an altitude of 360 m commonly in the jungles about Manbhoom, in the Madras presidency, Malabar and Coromandal Coasts, Coachin, Travancore, Southern India, Orissa, Uttar Pradesh, Bihar, Andhra Pradesh and Mysore [8] . It is exported from Mumbai, Madras, Cochin, Cocanada and Calcutta [5].

Scientific Classification

• Kingdom- Plantae
• Division-Magnoliophyta
• Class- Magnoliopsida
• Order- Gentianales
• Family- Logianiaceae
• Genus- Strychnos
• Species- nux-vomica

Vernacular Names

Strychnos nux-vomica L. is known by different names in different areas of the world, as follows [4, 6, 7, 8, 9, 10]:

• English- Nux vomica, Strychnine tree, Poison nut, Quaker button, Snakewood
• French- Noix vomiqu
• German- Gemeiner Brechnussbaum
• Arabic- Hub uljarab
• Sanskrit- Kupilu, Kulaka, Vishamushti, Vishtindu
• Hindi- Jahar, Kuchla, Kajra, Bishtendu
• Punjabi- Kagphala
• Bengali- Kuchila
• Telugu- Mushtivittulu, Muchidi
• Assammese- Ajraki, Habbulgurab, Kuchila
• Marathi- Kajra, Kuchala
• Tamil- Yetti, Yetti-kottai, Kakotee, Yettimaram
• Malayalam- Kanjiram, Kannirakkuru
• Burma- Khaboung
• Gujarat- Kuchla, Kochala, Jherkochla
• Orissa- Kachila

Phytochemical Constituents

Strychnos Nux-Vomica L. usually contains about 1.8 to 5.3% of the indole alkaloids strychnine and brucine (Figure 1) as main constituents out of which Srtychnine is physiologically much more active [5]. These alkaloids occur not only in seeds but also in the roots, wood, bark, leaves, fruit pulp and the hard fruit shells [4]. They usually contain 1.23% of strychnine [C21H22O2N2; mp: 286-288] and about 1.55% of Brucine [C23H26O4N2; mp: 178 degree] beside other minor alkaloidal constituents [4, 5, 6] like vomicine, α-columbrine, β-columbrine, 3-methoxyicajine, prostostrychnine, novacine, n-oxystrychnine, pseudostrychnine, isostrychnine, chlorogenic acid and glycoside, loganin [11, 5]. The bitter taste and highly poisonous action of Strychnos Nux-Vomica L. are chiefly due to the presence of these alkaloids [8, 12].

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Figure1: Active phytochemical Strychnine and Brucine present in S.nux-vomica L.

Pharmacological Actions

The physiological actions of the drug are due to the presence of these phytochemicals. These are nervine, stomachic, tonic, aphrodisiac, spinal, respiratory and cardiac stimulant. Strychnos Nux-Vomica L. is used in the treatment of anemia, lumbago, asthma, bronchitis, constipation, diabetes, malarial fever, skin disease, paralysis, muscle weakness and appetite loss [9, 19]. In excessive doses it is a virulent poison producing stiffness to muscles and tetanic convulsions ultimately leading to death [4, 5, 7, 8, 12, 13, 14].

Collection and Authentication of Selected Medicinal Plant

Fresh leaves of Strychnos Nux-Vomica Linn. was collected from the herbal garden, department of Ilmul Advia, Faculty of Unani Medicine, Aligarh Muslim University, Aligarh. The description found in Unani literature was used to validate the identity of medicinal plant. Additionally, the sample was verified for authencity by the pharmacognosist of the same department.

Preparation for Test Samples of Leaf of Selected Test Drug

Samples of fresh leaves was washed with water and foreign material and other contaminants was removed from it. Microscopic examination was done using standard method as per the guidelines.

Chemicals

The chemicals like Safranin stain, 50% Ethanol, Glycerin, were used. Entire chemicals used in experiments were of analytical grade.

Macroscopic Analysis

Fresh leaves of the plant was evaluated for various thorough morphological and organoleptic parameters such as shape, size, color, odor, taste, leaf margin, apex, texture, presence or absence of petiole, phyllotaxy etc. which were recorded in accordance of standard textbooks [15, 5, 16].

Microscopic Examination

Microscopy was done to analyze structure of epidermal cells, structure, distribution and type of stomata, structure and distribution of trichome on the fresh leaves.

Quantitative Microscopy

Quantitative microscopy was done to determine the number of epidermal cells, number of stomata and stomatal index, no of trichomes, palisade ratio of leaves. For this, fresh leaf was washed thoroughly with tap water followed by double distilled water, after which it was dried and thin transverse section of leaf was made with the help of fine blade. The fine transverse section of leaf was than shifted to petridish containing water and then shifted to watch glass holding 2-3 drops of safranin. After sometime, section was taken and rinsed with water. Excess stain was removed by ethanol. Section of leaf were transferred to slide, covered with cover slip and observed under microscope.

Leaf Surface Study

Stomatal number: Stomatal number (SN) or stomatal density is defined as the average number of stomata count in 1 mm square of the leaf within both upper and lower epidermises. Stomatal length and Osteolar length: It were measured with the help of software available OPTIKA B-290 microscope software. Total stomatal and total osteolar length was measured accordingly. Stomatal index: Percentage of number of stomata to the total number of epidermal cell (where each stomata is also considered to be a single epidermal cell [5, 17]. Procedure: For determination of stomatal number and stomatal index within both upper and lower epidermises were peeled off from fresh young leaves using a pair of forceps, razor and by sticking transparent cotton tape. The peeled section was fixed on slide by glycerin and examined under OPTIKA binocular digital microscope B-290 using 40X magnification. Numbers of stomata per mm square were recorded for stomatal number. To calculate exact, accurate and standard values five readings were taken for each, and the slides were photographed.

Stomatal Index was calculated as per following formulae:

S = Number of Stomata per Unit Area

( ) ( ) S×100 Stomatal Index= S+E

E= Number of ordinary epidermal cells in the same Unit Area

Vein islet number: It is the average number of vein islet enclosing small green area in 1 sq. mm leaf surface [5, 17]. Veinlet termination number: It is the determination of average number of terminated veinlet in 1 mm square of leaf surface area taken from region of midrib to margin of the leaf veinlet termination, the ultimate free end of veinlet [5, 17]. Procedure: To determine vein islet and vein termination number, lamina of leaf between midrib and margin was cut into small pieces about 1-3 mm square and boiled in a concentrated solution of chloral hydrate for 15 minutes till the discoloration of pieces. The transparent fragments were transferred into glass slide and observed under microscope at magnification of 10X. Vein-islets were counted in 1mm2 area. Along with veins-islets, the veinlet terminations were also, counted which were inside the square only. To calculate exact, accurate and standard values five readings were taken for each vein-islet and vein termination number, and the slides were photographed. Palisade ratio: Palisade ratio is defined as the average number of Palisade cells below single upper epidermal cell [5]. It is an important parameter for determination and characterization of leafy drugs [18]. Procedure: Small pieces (1-2mm) of leaf grown in full sun light were taken and cleared by boiling in 200% chloral hydrate solution. The cleared pieces were mounted and examined under microscope. A number of groups of each of four upper epidermal cells were first focused. Then by minor rotation of the fine adjustment, the under lying palisade cells were focused within the area of four epidermal cells. Palisade ratio was then obtained by dividing the number of palisade cells by 4. Five readings were taken from different pieces in order to obtain accurate average [19, 5].

Macroscopic Examination

The results of the macroscopic and organoleptic examination established that Strychnos Nux-Vomica L. is a medium sized deciduous tree with simple, broad, orbicular to broadly elliptic to ovate leaves which are glabrous, bright green, shiny and smooth. Leaves are opposite, petiolate with entire margin having 3 veins running along from base parallely (Figure 2; Table 1). The findings are than co-related with other research papers also.

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Microscopic Examination

The results of micromorphology reveal that the leaves of Strychnos Nux-Vomica L. Consists of anomocytic stomata which are kidney shaped. The epidermal cells are polygonal to irregular in shape. Beneath the epidermal cells numerous parallel palisade cells were found which are filled with chloroplast (Table 2).

Quantitative Microscopic Examination

The quantitative analysis of leaves of Strychnos Nux- Vomica L. reveals that the number of stomata vary from 14 to 22/mm2 and the epidermal cells varies from 186 to 250/ mm2. The stomatal indexes were calculated from the mean values of epidermal cells and stomatal number. Therefore stomatal index is 7.62 (Figure 3; Table 3).

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