|Year : 2013 | Volume
| Issue : 2 | Page : 193-199
Macro-microscopic examination of leaves of Cinnamomum malabatrum (Burm. f.) Blume sold as Tamalapatra
KN Sunil Kumar
Senior Research Officer, Department of Pharmacognosy, SDM Centre for Research in Ayurveda and Allied Sciences, Kuthpady, Udupi, Karnataka, India
|Date of Web Publication||10-Oct-2013|
K N Sunil Kumar
Senior Research Officer, Department of Pharmacognosy, SDM Centre for Research in Ayurveda and Allied Sciences, Laxminarayana Nagar, Kuthpady, Udupi - 574 118, Karnataka
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Leaves of Cinnamomum tamala Nees & Eberm. (Lauraceae) commonly known as 'Tamalapatra' is a highly reputed commodity in drug and spice trade. Its adulteration with other leaf species belonging to genus Cinnamomum is found to be a common practice in India and other parts of the world. Thorough macroscopic and microscopic investigations are essential to differentiate them. Survey of South Indian crude drug markets revealed that in place of C. tamala some other leaves of Cinnamomum species are sold. Fresh leaves of various Cinnamomum species, including C. tamala, growing in south India were collected and studied to establish their correct identity. Leaves sold in markets of S. India under the name of Tamalapatra were subjected for detailed macro-microscopic evaluation including maceration and powder microscopy. Leaves of Cinnamomum malabatrum showed many distinguishing macro-microscopic characters, which will serve as markers to differentiate them from C. tamala the official source of Tamalapatra. Though macroscopy will serve the purpose of identification of the entire drug, microscopy had revealed the identity of the commercial substitute even in fragmented and powdered form. Macro-microscopic identity of C. malabatrum is established in comparison with the official drug, further chemical and biological studies may be confirmative in deciding the leaves as a substitute or adulterant.
Keywords: Cinnamomum tamala, Cinnamomum malabatrum, maceration, micrometry, powder microscopy, quantitative microscopy
|How to cite this article:|
Sunil Kumar K N. Macro-microscopic examination of leaves of Cinnamomum malabatrum (Burm. f.) Blume sold as Tamalapatra. AYU 2013;34:193-9
| Introduction|| |
Adulteration is a major problem met during the assessment of identity and quality of many herbal drugs.  Difficulty arises when they are in the dry state and especially belonging to leaf parts of the plants, where they are usually found to be broken or powdered. For establishing their correct identity they are needed to be examined thoroughly under the microscope. Leaves of the same genus are found to exhibit number of similar common macro-microscopic characters and hence most likely to be used as an adulterant for official drug. Cinnamomum is a genus of the family Lauraceae having many number of examples related to the issue of adulteration with closely knit species.  Survey of the local crude drug market of south India revealed that leaves of Cinnamomum malabatrum are sold commonly in place of the official drug C. tamala. As Tamalapatra is an important commodity in Ayurvedic medicine,  it was thought worth to undertake the present investigation.
| Materials and Methods|| |
Dried leaves sold as Tamalapatra were collected from markets of various places of India. The authentic samples of leaves of C. malabatrum were collected from Tropical Botanical Garden and Research Institute, Palode - Trivandrum in Kerala. Leaves were dried in the shade and few leaves preserved in Formalin-Alcohol-Acetic acid solution were used for histological studies. Powder of the dried leaves sift through mesh 40 was stored in glass vials and used for microscopic evaluation.
Instrumentation and techniques
Detailed macroscopy of leaves of C. malabatrum was studied and authenticated with the help of floras. , Leaves were processed as per the standard procedures for histological examinations, and microscopic characters were drawn with prism type of camera lucida. Isolation of various elements was carried out by Schultz's maceration process or by boiling with 5% KOH. Measurements of the various elements were taken by using stage and ocular micrometers. The microscopic diagnostic characters of the powder were studied by clearing the powder with chloral hydrate. Cell contents were tested with usual reagents. , Photomicrographs were taken using leica microscope attached with canon digital camera.
| Results|| |
Photographs detailing the macroscopic features of both the leaves are shown in [Figure 1]. Morphological descriptions outlined in floras , are used as a guideline to propose diagnostic differentiating macro-microscopic characters of the official source of Tamalapatra. Macroscopic and sensory characters of the leaf were compared with C. tamala leaf [Table 1]. The results indicated the variation in size of leaf blade and petiole (almost double than that of C. tamala), surface (glabrous, unlike C. tamala), venation (veins reaching up to the tip unlike that of C. tamala) and taste (more mucilaginous in contrast to that of C. tamala).
|Table 1: Comparative macroscopic and organoleptic characters of leaves of C. malabatrum and C. tamala|
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|Figure 1: Macroscopic characters of leaves of Cinnamomum malabatrum and Cinnamomum tamala|
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The transverse section passing through the midrib of the leaf and petiole of both the leaves are shown in [Figure 2] and [Figure 3] and their comparative histological characters are detailed in [Table 2] and [Table 3]. The microscopical characters of C. malabatrum are as follows:
|Table 2: Comparative microscopic characters of the transverse section of petiole of C. malabatrum and C. tamala |
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|Table 3: Comparative microscopic characters of the transverse section of midrib of C. malabatrum and C. tamala |
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Transverse section of petiole
Circular to somewhat reniform in outline, with elevated and grooved margin (plano-convex in C. tamala), covered with thick cuticle and bear few simple unicellular and bi-cellular short trichomes, an arc of meristele with broad xylem rays (narrow longer and sinuously running in C. tamala) located in the center is encircled by discontinuously running band of stone cells and fibers, which are bigger in size, highly lignified and more crowded at the basal region of the meristele (uniformly distributed in C. tamala and smaller in size), the ground tissue is collenchymatous and embedded with dark brown coloring matter and at places occasional lignified fibers (absent in C. tamala), rows of volatile oil cells are located underneath the epidermis and mucilage, tannin and oleoresin are traversed throughout the ground tissue; prismatic, acicular, raphides and rosette crystals of calcium oxalate are embedded in the collenchymatous tissue [Figure 2]a and [Figure 3]a.
Transverse section of leaf passing through midrib
Broadly convex dorsiventrally (shows number of winged projecting elevations at the lower side in C. tamala) shows an arc of well-developed conjoint collateral oval shaped meristele (triangular in C. tamala) in the center of the midrib and dorsiventral laminar extensions on its lateral sides. Pericyclic band encircling the meristele shows continuously running narrow arc of fibers on the upper side and discontinuously running groups of fibers on its lower side (in C. tamala it is discontinuous throughout except at two lateral sides). Both the upper and lower epidermal cells are thick-walled lignified on their inner walls, embedded with stomata on the lower side only, covered with thick cuticle and bear few simple and glandular trichomes like that of petiole (they being plenty on the lower side of the midrib region in C. tamala). 5 and 6 rows of lignified thick-walled parenchymatous cells are located underneath the upper and lower epidermis of the midrib it being 10-12 rows and extending up to the pericyclic band in the middle region underneath the upper epidermis. 5 and 6 rows of parenchyma cells embedded with tannins are located on both, dorsal and ventral sides of the meristele.
Lamina shows a row of narrow and compactly arranged palisade cells embedded with oval to spherical oil cells followed by few rows of spongy parenchyma embedded with mucilage cells, small parenchyma embedded with mucilage cells and small vascular bundles sheathed dorsiventrally with sclerenchymatous band reaching up to both epidermis of the lamina [Figure 2]b and [Figure 3]b.
Microscopy of macerated leaf
Leaf on maceration yielded information on different tissue system from the petiole and lamina, the inference is found to be more informative in differentiating the two species. The characters observed are illustrated in [Figure 4].
Micrometric measurements were taken for various tissues in the macerated leaf. The data is presented in [Table 4].
Values for different leaf constants are presented in [Table 5].
|Table 5: Quantitative microscopy of leaves of C. malabatrum and C. tamala|
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Presence of anomocytic stomata embedded in sinuously walled lower epidermal fragments (often less sinuously walled, papillate epidermis bearing paracytic stomata in C. tamala); rare occurrence of unicellular, rarely septate covering trichomes (up to three-celled covering trichomes and pearl-glands abundant in C. tamala); long sclereidal fibers with wide lumen and pitted wall and large stone cells (absent in C. tamala); fragments of annular vessels (reticulate in C. tamala) and spiral vessels; comparatively abundance of mucilage cells (volatile oil cell abundant in C. tamala) and plenty of square-like and hexagonal prismatic crystals of calcium oxalate (predominantly rod shaped and few acicular in C. tamala) are of diagnostic value in identifying the leaf powder under microscope. Characters of the powdered leaves are illustrated in [Figure 5].
| Discussion|| |
On account of wider distribution in Western Ghats, morphological similarity and the characteristic fragrance, leaves of C. malabtrum has been sold in crude drug markets for flavoring various edibles, also for use in many Ayurvedic and Siddha formulations. The market samples were analyzed to detect its identity by subjecting it to exhaustive macro-microscopic evaluation; the characters were recorded in comparison with authentic samples of C. malabatrum. Macrosopical and organoleptic features such as size of the leaf up to 25-30 cm, venation reaching up to the tip of the leaf, grooved and glabrous petiole, less aromatic and mucilaginous taste can easily differentiate the substitute from C. tamala leaf. Reniform to urn shaped outline of the TS of petiole, differences in the outline of the transverse section of leaf, rare occurrence of trichomes, and presence of anomocytic stomata in non-papillose epidermal cells in C. malabatrum can be diagnostic features to differentiate the two. The macro-microscopic characters of leaf petiole and lamina of samples obtained from the markets were found to be exactly in agreement with that of authentic C. malabatrum.
| Conclusion|| |
Detailed macro-microscopic profiles were laid down for C. malabatrum leaves, which will serve as diagnostic tools for its differentiation from official C. tamala. Exhaustive chemical and pharmacological evaluation might be conclusive to designate the species as a substitute or as an adulterant to Tamalapatra.
| Acknowledgments|| |
Author is grateful to revered President, Dr. D. Veerendra Heggade, President and Dr. B. Yashovarma, Secretary, SDM Educational Society for encouragement. Author is also grateful to Dr. B. Ravishankar, Director - SDM Centre for Research in Ayurveda and Allied Sciences, Udupi, Malati Chauhan and Mr. APG Pillai for guidance. Thanks are due to Dr. P George, Dr. Mathew Dan and Dr. E Santhosh Kumar, TBGRI, Trivandrum for supplying authentic plant materials. Dr. Indira Balachandran and Dr. Remashree, CMPR, Arya Vaidya Sala, Kottakkal are acknowledged for providing Photomicrography facility.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]