RESULTS: CP and EE were found to contain appreciable levels of total phenolic contents (50.6 and 33.41 g kg(-1) as gallic acid equivalent) and total flavonoid contents (205.6 and 244.8 g kg(-1) as rutin equivalent), respectively. DPPH free radical scavenging activity of CP is superior to EE (P < 0.05) showing IC(50) of 77.2 and 995.1 µg mL(-1), respectively. Methicillin-resistant Staphylococcus aureus (MRSA), Bacillus subtilis, Pseudomonas aeruginosa and Salmonella choleraesuis were tested against CP and EE. Only MRSA was the most susceptible bacteria to CP. GC/MS studies resulted in the identification of 79 and 73 compounds in CP and EE, respectively. The most abundant components of EE included β-pinene (24.92%) and 1-dodecene (24.31%). While the major compound in CP were 1,6-octadien-3-ol,3,7-dimethyl (11.55%), cinnamaldehyde (56.15%) and 1-phenyl-propane-2,2-diol diethanoate (11.38%).
CONCLUSION: This study suggests that the essential oils from Cinnamomum pubescens Kochummen and Etlingera elatior could be potentially used as a new source of natural antioxidant and antibacterial in the food and pharmaceutical industries.
METHODS: Different parts of the plants were subjected to sequential extraction method. Cytotoxicity of the extracts was determined by dimethylthiazol-2-yl)- 2,5diphenyl tetrazolium bromide (MTT) assay on 2 human cancer (colon and breast) and normal (endothelial and colon fibroblast) cells. Anti-angiogenic potential was tested using ex vivo rat aortic ring assay. DPPH (1,1-diphenyl-2-picrylhydrazyl) assay was conducted to screen the antioxidant capabilities of the extracts. Finally, total phenolic and flavonoid contents were estimated in the extracts using colorimetric assays.
RESULTS: The results indicated that out of 6 plants tested, 4 plants (Nicotiana glauca, Tephrosia apollinea, Combretum hartmannianum and Tamarix nilotica) exhibited remarkable anti-angiogenic activity by inhibiting the sprouting of microvessels more than 60%. However, the most potent antiangiogenic effect was recorded by ethanol extract of T. apollinea (94.62%). In addition, the plants exhibited significant antiproliferative effects against human breast (MCF-7) and colon (HCT 116) cancer cells while being non-cytotoxic to the tested normal cells. The IC50 values determined for C. hartmannianum, N. gluaca and T. apollinea against MCF-7 cells were 8.48, 10.78 and 29.36 μg/ml, respectively. Whereas, the IC50 values estimated for N. gluaca, T. apollinea and C. hartmannianum against HCT 116 cells were 5.4, 20.2 and 27.2 μg/ml, respectively. These results were more or less equal to the standard reference drugs, tamoxifen (IC50 = 6.67 μg/ml) and 5-fluorouracil (IC50 = 3.9 μg/ml) tested against MCF-7 and HCT 116, respectively. Extracts of C. hartmannianum bark and N. glauca leaves demonstrated potent antioxidant effect with IC50s range from 9.4-22.4 and 13.4-30 μg/ml, respectively. Extracts of N. glauca leaves and T apollinea aerial parts demonstrated high amount of flavonoids range from 57.6-88.1 and 10.7-78 mg quercetin equivalent/g, respectively.
CONCLUSIONS: These results are in good agreement with the ethnobotanical uses of the plants (N. glauca, T. apollinea, C. hartmannianum and T. nilotica) to cure the oxidative stress and paraneoplastic symptoms caused by the cancer. These findings endorse further investigations on these plants to determine the active principles and their mode of action.