Orchids of Dibru-Saikhowa: A Systematic Review on Their Traditional Use, Pharmacological Activity and Phytochemistry.

BACKGROUND: Dibru-Saikhowa National Park and Biosphere Reserve (DSNPBR), Assam, India, is a part of biodiversity hotspots and a store house of many orchid species. This systematic review was conducted to document the medicinal importante of orchids available in DSNPBR and to analyse their importance in drug discovery.

METHODS: This systematic review was conducted using the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Scientific databases were used to search relevant literature to document ethnomedicinal uses, pharmacological activity and phytochemistry of orchid species available in DSNPBR.

RESULTS: We have analysed 84 articles to document relevant information on 52 orchid species available in DSNPBR. Dendrobium (n=13) is the top genus. Different orchid species available in DSNPBR were used traditionally in India, Nepal, Bangladesh, and China to cure gastrointestinal disorders, disease-associated pain and inflammation, skin diseases, wound, arthritis, menstrual pain, tuberculosis etc. The pre-clinical investigations confirmed that extract/fraction/isolated compounds of orchids possess antirheumatic, anticancer, antitumor, anti-inflammatory, antidiabetic, antimicrobial, nephroprotective and neuroprotective activities through different mechanisms. Biomolecules isolated from orchid species like Dendrobium nobile alkaloids, polysaccharides have shown a potential to be developed as future drug molecules. Many phytochemicals isolated have demonstrated in vitro anticancer activities. The lack of clinical data in support of the therapeutic effectiveness of orchids is a major limitation.

CONCLUSION: Orchids found in DSNPBR hold great significance in traditional culture for their medicinal properties and have been effectively studied for their bioactivities. Nevertheless, to confirm their effectiveness as therapeutics, conducting methodical research, examining their molecular mechanisms, and performing toxicity tests are necessary.