Gynmema sylvestre - A Potentional Medicinal Herb

 

Suyog S. Karande*, Dattaprasad N. Vikhe, Ravindra S. Jadhav

Pravara Rural College of Pharmacy, Pravaranagar, Loni. Tal – Rahat, Dist – Ahmadnagar, Maharashtra 413736.

 

Abstract:

Gymnema sylvestre (Gs) is a well proven anti diabetic plant and used in Indian system of medicine for long period. A new variant of Gs was identified having hairy leaf. This Gs hairy variant species was subjected for pharmacognostical studies and screened for phytochemical analysis and correlated with the previous work done normal non hairy species. The leaves were analyzed for macroscopic and microscopic characteristics by taking microtome sectioning and stained for viewing in slides. The dried powdered leaf was subjected to fluorescent study using chemical reagents and viewed under visible and UV light to study the coloring pattern of the powdered particles interacting with the reagents. The powder was subjected for physicochemical studies using Indian Ayurvedic Pharamacopoeia procedure. The different extractions were done by using 100%, 50% ethanol and water. These extracts were subjected for preliminary qualitative analysis, quantitative estimation of terpenoides, alkaloids and marker compound Glycemnic acid.

 

 

 

INTRODUCTION:

Gymnema sylvestre (Gs) is an Indian medicinal plant used for Diabetes mellitus in Siddha, Ayurveda and Folk medicine. Modern scientific studies also proved its efficacy against Diabetes (Persaud1999)1. While collecting G. sylvestre, we found a new variant differ in morphological character from normal. This variant was multiplied by stem cutting and maintained at Tamil University Herbal Garden, Tanjore. We noticed that the new variant has hairy leaf, but leaf of normal Gs doesn’t have hair in both upper and lower surface. More over, flowering was not noted in the hairy new variant for the past two year during its growth. Sangeetha and Jagadeesan, 2012 screened for phytochemical characterization of the leaf of new variant and normal Gs and reported the variations found between these two species 2. For validating the above variations, this work was carried out to investigate the leaf and its different extracts of Gs hairy variant under macroscopic and microscopic features, physicochemical parameters, phytochemical analysis and chromatographic analysis. Gymnema sylvestre R. Br. is a valuable herb belonging to the family Asclepiadaceae, and widely distributed in India, Malaysia, Srilanka, Australia, Indonesia, Japan, Vietnam, tropical Africa and the southwestern region of the People’s Republic of China.

 

Plant description:

G. sylvestre is a slow growing, perennial, woody climber, distributed throughout the India, in dry forests upto 600 m height. It is mainly present in the tropical forest of Central and Southern India.

 

Fig: leaf of Gymnema sylvestre

 

It is also found in Banda, Konkan, Western Ghats, Deccan extending to the parts of western and northern India [6-8]. The plant is a large, more or less pubescent, woody climber. The leaves are opposite, usually elliptic or ovate (1.25 – 2.0 inch x 0.5-1.25 inch). Flowers are small, yellow, in axillary and lateral umbel in cymes; Follicles are terete and lanceolate upto 3 inches in length. The Calyx-lobes are long, ovate, obtuse and pubescent. Corolla is pale yellow campanulate, valvate, corona single, with 5 fleshy scales. Scales adnate to throat of corolla tube between lobes; Anther connective produced into a membranous tip, pollinia 2, erect, carpels 2, unilocular; locules many ovuled ^2,3,4,5.

 

Taxonomical classification

 

Pharmacognostic evaluation:

Macroscopic evaluation:

Leaves of G. sylvestre are green in colour and stem is hairy and light brown. Leaf is 2-6 cm in length and 1-4 cm in width. The leaves are simple, petiolate, rounded to cordate base, margin entire, opposite with acute apex, reticulate venation, pubescent on both the surfaces. The odour is characteristic and taste of leaf is slightly bitter and astringent. It also possesses remarkable property of paralyzing the sense of the taste for sweet substances for few hours [7,8].

 

Microscopic Characteristics:

 

Microscopically G. sylvestre is observed that hairs are nonglandular and profusely present all over the surface. In leaves there are five vascular bundles. These are fan shaped in the center flanked on either side by two small bundles. The midrib has a ventral bulge. In the lamina, rosette crystals of calcium oxalate are present. In the spongy parenchyma, idoblasts are present (6).

 

Morphological Studies:

The collected leaves were taken free hand as well as microtome sections and were double stained. All slides were stained initially by alcoholic safranin (0.5%) and dehydrated by employing graded series of ethyl alcohol (30%, 50%, 70%, 90% and absolute alcohol). After washing, slides were stained with 0.25% fast green in clove oil and xylol-alcohol (50-50) and passed through xylol and mounted in glycerin. Stained hand sections and macerated materials were examined under compound microscope. Vein-islet number, stomatal index and palisade ratio was found on using samples treated in 5% KOH solution. For determining stomatal index, epidermal pealing from both surfaces of a fresh leaf was taken and counting was recorded from different areas of each piece (i.e. number of stomata as well as epidermal cells per 1 sq. mm area). Stomatal index value is then calculated by using the formula [S/(E+S)]100 where E and S stand for number of epidermal cells and number of stomata of unit area respectively. Palisade ratio was determined by using fresh leaves.

 

Petiole:

Transverse section of petiole is horse shoe shaped. The epidermis is barrel shaped single layered, thick walled covered with uniseriate, multicellular, non-glandular trichomes. The cortex is collenchymatous and vascular bundles are amphicribal and three in number. Well-developed phloem consists of sieve tubes, companion cells and phloem parenchyma. The xylem consists of vessels, tracheids and tracheidal fibres. The starch grains are polygonal, simple or compound in two or many groups. The rosette crystals of calcium oxalate are present more towards the centre^7,9.

 

Lamina:

The epidermal cells of lamina are square shaped with outer convex wall and thin cuticle. When viewed transversally, epidermal cell surface are interrupted with trichomes, which are uniseriate, multicellular with 2 to 5 celled, present in abundance on both the surfaces. Single layered closely arranged palisade cells are present just below the adaxial epidermis. Vascular bundles are amphicribal and the mesophyll is 3-5 celled thick^7,9.

 

Stem:

The transverse section of stem is circular in outline. The epidermis is barrel shaped and thick walled. Trichomes are multicellular, uniseriate and 185-485µ long and 9-25µ broad. The cork is 3 to 5 layered thick, and cortical cells are latterly elongated and collenchymous. The phloem well developed consists of large sieve plates, companion cells and phloem parenchyma. The xylem is in the form of a continuous cylinder transverse by narrow medullary rays. The endodermis is conspicuous and the pericycle is broad^7,8.

 

Powder:

The powdered material is slight yellowish green in colour, bitter in taste with pleasant aromatic odour. On microscopic examination, it shows thick walled, uniseriate multicellular trichomes, anomocytic stomata, idioblast with rosette crystals of calcium oxalate, starch grains, remnants of collenchymatous and parenchymatous cells; vessels, tracheids, tracheidal fibres, bast fibres and sieve plates^4,7,8.

 

Powder microscopy of dried powder of G. sylvestre leaf

The powder of was greenish yellow, without characteristic odor and with slightly bitter taste. When powder was mounted with chloral hydrate, phloroglucinol and HCl the following elements were observed:

 

A- Rosette Crystals,                                 B, Trichomes,                                                   C, Xylem vessel

 

Physico chemical properties:

Physico-chemical evaluations of leaves of G. sylvestre

 

Preliminary phytochemical screening

 

CONCLUSION:

As there is no pharmacognostical anatomical work on records for this traditionally much valued herb, present work is taken up in the view to lay down the macroscopic and microscopic standards, which could be used in deciding the genuineness of the herb, irrespective of their collection from different sources. The colored photographs of the leaves of the above mentioned plant might facilitate the researcher for identification.

 

ACKNOWLEDGEMENTS:

Authors thankfully acknowledge the facilities provided by the Department of Pharmacognosy, Pravara Rural College of Pharmacy Pravara Nagar.

 

REFERENCES:

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Received on 24.05.2022       Modified on 19.06.2022 Accepted on 04.07.2022      ©A&V Publications All right reserved Research J. Science and Tech. 2022; 14(3):193-196. DOI: 10.52711/2349-2988.2022.00032