Antioxidant, anticancer and antimicrobial effects of In vitro developed protocorms of Dendrobium longicornu

In vitro seed germination and protocorms formation were successfully established in traditionally used Dendrobium longicornu. Fresh protocorms (178.34 g - 183.90 g) were produced on the elicitor of Alternaria sp, Bacillus subtilis and Fusarium solani supplemented MS-medium. Methanol extract of D. longicornu protocorms has scavenged 94.31 % of DPPH radicals at 1000 μg/mL. Its 117.56 μg/mL concentration has scavenged 50 % DPPH radical (IC₅₀). Similarly, it inhibits 25.39 % and 27.80 % HeLa and U251 cells at 500 μg/mL. The IC₅₀ was found as 350.06 μg/mL and 507.22 μg/mL for HeLa and U251 cells respectively. Further, it inhibited the growth of E. coli, K. pneumoniae and E. cloacae with the zone of inhibition 4, 2 and 2 mm respectively. In conclusion, protocorms developed through in vitro seeds culture have accumulated and synthesized bioactive secondary metabolites. Therefore, protocorms could be utilized to the isolation of compounds for formulation of herbal drugs without damaging natural populations.

Keywords: Antibacterial assay; D. longicornu extract; DPPH assay; MTT assay; Protocorms.