Cytotoxic Effect of Selected Wild Orchids on Two Different Human Cancer Cell Lines

Majority of the orchid species are used in the traditional medicines for the treatment of several diseases. They are the sources of polysaccharides, phenanthrenes, bibenzyl derivatives, revesteral, stilbenoids and polyphenol compounds. This study explored the cytotoxic activity of seven wild orchid species and identification of medicinally active compounds. The extracts of orchid species were screened for cytotoxic effect on the human cervical cancer cells (HeLa) and human glioblastoma cells (U251) using an MTT assay. The medicinally active compounds of high cytotoxic extracts were identified by GC-MS resulting in many stilbenoids and phenolic derivatives. The extract of Dendrobium transparens (DTs) and Vanda cristata (VCw) showed high cytotoxic effect towards the HeLa and U251 cell lines (IC₅₀ of DTs: 382.14 μg/ml and 75.84 μg/ml respectively and IC₅₀ of VCw: 317.23 μg/ml and 163.66 μg/ml respectively). This study concludes that they could be used as cancer therapeutics.

Keywords: Bioactive compounds; Bioactive plant product; Biological sciences; Botany; GC-MS; MTT assay; Natural product; Orchids; Pharmaceutical science; Plant biology.