Pharmacognostic, Physicochemical and Phytochemical Studies on Carica papaya Linn. Leaves

Papaya (Carica papaya Linn.) is commonly known for its food and nutritional values throughout the world. The medicinal properties of papaya fruit and other parts of the plant are also well known in traditional system of medicine. During the last few decades considerable progress has been achieved regarding the biological activity and medicinal application of papaya and now it is considered as valuable nutraceutical fruit plant. The present study deals with the microscopic evaluation of leaves of Carica papaya Linn., to establish the salient diagnostic features for the leaf. The leaf shows abundant sphaeraphides and rhomboidal calcium oxalate crystals. The leaf shows no trichomes. Micromorphological studies conducted on the leaf gave value of stomatal index to be 31.56 ± 3.41, vein termination number 3-4, and palisade ratio to be 12.65 ± 1.57. The leaf shows a continuous network of veins. Histochemical tests performed indicate the presence of alkaloids and starch. Powder study shows the presence of sphaeraphides, starch grains and rhomboidal calcium oxalate crystals, apart from regular characters such as stomata and spiral xylem. Physicochemical parameters such as extractive values, ash values and moisture content have also been studied for the leaf. The results of this study could be useful in setting some diagnostic indices for identification, authentication and preparation of the monograph of the plant.