Assessment of Antioxidant and Cytotoxic Activities of Extracts of Dendrobium crepidatum

Abstract

Dendrobium crepidatum is an epiphytic orchid found in south Asia including Nepal and China. This orchid species is widely used in traditional Chinese medicine (TCM) for the treatment of cancer, diabetes, cataracts, and fever. The objectives of the present research were to assess the antioxidant and cytotoxic properties of its stem’s extracts with the identification of bioactive secondary metabolites. The antioxidant and cytotoxic activities were evaluated using the DPPH (2,2-diphenyl-1-picrylhydrazyl) and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays, respectively, and compounds were identified using GC–MS (gas chromatography and mass spectrometry). Ethanol and acetone extracts scavenged 94.69 ± 0.10% and 93.41 ± 0.86% of DPPH free radicals, respectively. They showed 50% inhibition of DPPH free radicals (IC50) at concentrations of 73.90 µg/mL and 99.44 µg/mL, which were found to be statistically similar to that of ascorbic acid (control). Chloroform extract inhibited the growth of 81.49 ± 0.43% of HeLa (human cervical carcinoma) cells and hexane extract inhibited the growth of 76.45 ± 4.26% of U251 (human glioblastoma) cells at 800 µg/mL concentration. These extracts showed 50% inhibition of cell growth (IC50) toward both the HeLa and U251 cell lines at their high concentrations, which were found statistically significantly different from that of cisplatin drug (control). The above extracts showed antioxidant and cytotoxic properties, potentially due to the presence of tetracosane, triacontane, stigmasterol, and some phenol derivatives (2-methoxy-4-vinylphenol, 2-methoxy-5-(1-propenyl)-phenol, p-mesyloxyphenol, and 2,6-dimethoxy-4-(2-propenyl)-phenol). This study explores the potential of this orchid in alternative medicine toward the development of drugs from its medicinally active compounds.

In vitro propagation of the endangered orchid Dendrobium chryseum Rolfefrom protocorms culture

“…The chemical compound isolated from the stem of Dendrobium chryseum exhibited antioxidant activity (Yang et al, 2007) and pharmacological experiments showed that polysaccharides from the plant inhibited tumor growth and reduced blood glucose in vivo (Liu et al, 2009). As the species of Dendrobium such as Dendrobium longicornu and Dendrobium crepidatum were found to exhibit antioxidant and cytotoxic activities (Paudel et al, 2017;Paudel et al, 2019), it is expected to have the same type of activities in D. chryseum. As this orchid species has great significance in the floriculture industry and also has medicinal value, tissue culture should be promoted for its mass propagation and conservation.…”

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

“…Antioxidant effect of the extract was determined using a DPPH (2,2-diphenyl-1-picrylhydrazyl) free-radical scavenging assay [ 24 ]. The extract was diluted in methanol to prepare a series of concentrations (125, 250, 500 and 1000 μg/mL).…”

“…Anticancer effect of the extract toward human cervical cancer (HeLa) and brain tumour (U251) cell lines was determined using MTT colourimetric assay [ 24 ]. From the cell suspension, 5 × 10 3 cells in 100 μl of RPMI-1640 medium supplemented with l -glutamine, penicillin/streptomycin and 10 % fetal bovine serum (FBS) were dispensed into the well of a 96-well cell culture plate and incubated under the cell culture conditions at 37 °C and 5% CO 2 for 48 h to allow for adherence and growth of cells.…”

“…Gas chromatography-mass spectrometry (GC–MS; Shimadzu Europa GmbH, Germany) was used to identify the compounds [ 24 ]. Spectroscopic detection has involved an electron ionization system which utilized high-energy electrons (70 eV).…”

Comparative Cytotoxic Activity of Wild Harvested Stems and In Vitro-Raised Protocorms of Dendrobium chryseum Rolfe in Human Cervical Carcinoma and Glioblastoma Cell Lines

“…In particular, orchid species have been cultured with various techniques to synthesize bioactive molecules in vitro [ 34 , 35 ]. In the present study, D. chryseum was cultured in vitro to produce protocorms for the assessment of potential cytotoxic activity and comparison of such activities with its wild counterparts.…”