Ethnopharmacological profile of anti-arthritic plants of Asia-a systematic review

Background: Arthritis is not an inherited disease but caused by stimulation of some hidden arthritis susceptible genes lowering the quality of life throughout the world, particularly in developing countries. Objectives: To present a comprehensive review on ethnomedicinal and ethno-pharmacological information of Asian anti-arthritic plants. Data sources: Research articles published in English were searched using six search engines (1979-2017). A few additional records searched from other sources i.e. floras, inventories and bibliographies were also included. Data Extraction: Information regarding ethnobotany, pharmacology, phytochemistry and toxicity of plants used against arthritis was extracted from the selected literature. Results: A total of 159 medicinal plants that were reported to be used against arthritis belonging to 71 families among which Asteraceae and Lamiaceae were dominant. Most of the plants were from India (37 plant species) followed by Thailand (21), China (16), and Iraq (12). Twelve percent of plants were reported to be traditionally used in more than one country. Most of the plants were used against rheumatoid arthritis (65). The majority of the documented herbal preparations consisted of leaves (22%) followed by roots (13%) and the dominant formulation method was decoction (21 plants). Only six plants were reportedly evaluated for their in-vitro and 15 plants for in-vivo activities. Five pure compounds (allicin, thymoquinone, polyphenols, 1'-acetoxychavicol acetate and ginger oil) were reportedly isolated from the documented plants and tested against different arthritis models. Toxicity of certain plants was also reported. Conclusion: The present review summarizes the ethnomedicinal information of anti-arthritic plants and discloses scientific gaps in current knowledge. The majority of reported plants have not yet been scientifically authenticated and should be given more attention in future, especially those plants i.e. Carica papaya L. being used in more than one country