Introduction: Cannabis sativa; commonly known as Marijuana from the family Cannabaceae is an annual, dioecious and flowering plants. Cannabis has been part of Thai medicine for more than three centuries. There are various formulas that have cannabis as the ingredient. As cannabis has been an important source of medicinal substances, such as treat nausea, improve appetite, promoting sleep, relieve pain and anxiety. It is necessary to develop standardization for evaluating the safety, quality, and efficacy of cannabis material.
Objective: The aim of the current research was to investigate a pharmacognostic specification of Cannabis leaves throughout Thailand as per standard procedures.
Methods: The investigation deals with comprehensive pharmacognostic parameters according to WHO guideline; Macroscopic-microscopic characteristics, physicochemical parameters, phytochemical screening, and TLC fingerprinting of C. sativa leaves collected from 12 sources throughout Thailand. Results: Leaves are green and palmate (seven lobes), with serrate margin and acuminate apex. The epidermis leaf surface demonstrates the rectangular cell with striations, anomocytic stomata, veins, vein islet, vein termination and trichome. Cannabis trichomes consist of glandular trichome and unicellular trichome with cystolith and cicatrix. Hand-cut transverse section of mature leaves demonstrates the epidermis layer covered with cuticle and vascular bundles (xylem and phloem) can be found in this region. The mesophyll region is separated into palisade and light parenchyma cells with raphides of calcium oxalate crystals. Epidermis shows the presence of Uniseriate, unicellular covering trichomes. Segments of collenchyma was observed in midrib towards epidermis or aligned to epidermis. Powdered drug was presented epidermis, stoma, palisade, vessels, unicellular trichomes, cystolith, spiral vessels and fiber. Physicochemical studies revealed value of loss on drying (4.068 ± 0.084), total ash (14.360± 0.165), acid insoluble ash (2.726 ± 0.080), alcohol-soluble extractive (11.101 ± 0.223), water-soluble extractive (23.038 ± 0.306), and water content (7.954 ± 0.324). Phytochemical screening of Cannabis leave revealed the presence of phenolic compounds, flavonoids, alkaloids, diterpenes, triterpenes and steroids.
Conclusion: These studies will provide referential information for the correct taxonomical identification, standardization, and establishing monograph of cannabis leave in Thailand, these specific identities will be useful in identification and authentication of the raw drug.