Comparative pharmacognostical evaluation of nine different varieties of the leaves of Psidium guajava Linn.

Abstract

Objective: To explore the micro morphology and Physio chemical parameters of nine different varieties of the leaves of Psidium guajava Linn. (Myrtaceae). Methods: Macroscopy, microscopy, physicochemical analysis, preliminary phytochemical screening and other WHO recommended parameters for standardizations were performed. Results: Leaves (5-15cm × 4-6 cm) are dorsiventral, oblong – elliptic, dull grey to yellow green with entire margin, obtuse to bluntly acuminate apex and rounded to subcuneate base with short petiole. Morphology of the leaves showed no difference in all the varieties. A noteworthy feature Myrtaceae family is the presence of secretory cavities. Microscopic evaluation revealed that secretory cavities were absent in Bangalore, Chittidhar and it is present in the lower side in case of Anakapalli, Hafsi, Lucknow-46, Nagpur seedless and Red fleshed, but it was 80µm wide and present in the upper portion in Smooth green. Narrow secretory cavities observed at the periphery of the midrib in Lucknow-49. Calcium oxalate druses in dilated cells are present in Hafsi and Lucknow-46 alone. All varieties contain invariably multiple epidermis. Tannin is abundant in the tissue, but it is very less in Lucknow-49 and dark tannin accumulation seen in Red fleshed. In vascular bundle xylem less lignified, uniseriate thick walled in Anakapalli, thin walled dark elliptical sclerenchyma in Bangalore variety. Powder microscopy showed the presence of paracytic stomata, fragment of epidermis, conical and flagellate trichomes, fragment of palisade mesophyll, secretory cavity (absent in Bangalore, Chittidhar varieties), calcium oxalate crystals (present in Hafsi and Lucknow -46 varieties) and parenchymal cells. Vein islet & Termination number, stomatal number & index and other physico chemical tests like ash values, loss on drying, extractive values were determined. Preliminary phytochemical screening showed the presence of sterols, tannins, proteins and amino acids, flavonoids, volatile oil, terpenoids, saponin, carbohydrates and absence of alkaloids, mucilage, glycosides, fixed oil. Conclusion: Microscopic analysis was informative and provides useful information in the botanical identification, standardization for purity & quality and immense value in authentication of the different varieties of the leaves.