METHODS: Hence, the evaluation of the synergistic activity of PLEAF and ampicillin against MRSA local isolate was conducted with scanning electron microscopy (SEM).
RESULTS: The combinational effect of PLEAF fraction and ampicillin exhibited significant antibacterial activity against MRSA. Bacterial cells observations showed invagination, impaired cell division, extensive wrinkles, cell shrinkage, the appearance of a rougher cell with fibrous matrix and clustered cells which confirmed the synergistic effect of PLEAF and ampicillin against MRSA local isolate by SEM.
CONCLUSION: Conclusively, the in situ SEM observation proved the synergistic antimicrobial activity between PLEAF fraction and ampicillin to destroy the MRSA resistance bacteria which is an important aspect of PLEAF fraction to be used in the future combinational therapy.
EXPERIMENTAL PROCEDURE: The microbial limit test (MLT) studies indicated the suitable dosage of minimum and maximum gamma irradiation for leaf extracts as well as dried leaves of all the tested medicinal plants. Quantitative analysis of total phenolic content (TPC) analysis is based on calorimetric measurements determined using the Folin-Ciocalteu reagent with gallic acid (GA) used as the reference. In vitro cytotoxicity assay by using fibroblast (L929) cell lines was performed on each plant to determine the toxicity effect which sodium dodecyl sulfate (SDS) as the positive control. DPPH (2,2-diphenyl-1-picryl-hydrazyl) assay was conducted by using vitamin C and GA as the positive controls to determine the antioxidant property of each plant.
RESULTS AND CONCLUSION: The MLT analysis indicated that the suitable dosage gamma irradiation for leaf extracts was 6-12 kGy and dried leaves were 9-13 kGy. The amount of GA concentration in each plant increased significantly from 30-51 mg GAE g-1 before treatment to 57-103 mg GAE g-1 after treatment with gamma radiation. This showed no significant effect of in vitro cytotoxicity activity before and after treatment with gamma irradiation in this study. Effective concentration (EC50) values of Khaya senegalensis plant reduced significantly (P ≤ 0.005) from 44.510 μg/ml before treatment to 24.691 μg/ml after treatment with gamma radiation, which indicate an increase of free radical scavenging activity.
METHODS: These plants were collected, identified and the extracts were prepared by using conventional Soxhlet ethanol extraction technique. The venom neutralization activity was accessed in mice (20-25g) and number of mortalities was observed against clinically important snake (Naja nigricollis) venom. Present study also deals with in vitro membrane stabilizing activity of these plants against hyposaline induced human red blood corpuscles (HRBC).
RESULTS: Extracts of H. javanica and G. superba gave 80 % and 90 % protection to mice treated with minimum lethal dose of venom (LD(99)). These two plants showed significant neutralization effect against the venoms of Naja nigricollis venom. H. javanica and G. superba (25-100 mg/mL) produced significant changes of membrane stabilization of human red blood cells (HRBC) exposed to hyposaline-induced haemolysis.
CONCLUSIONS: We conclude that probably due to presence of various phytochemicals plays an important role in the anti-venom potential of these Indian medicinal plants against Naja nigricollis venom. The above observations confirmed that A. paniculata, C. magna, G. superba and H. javanica plant extracts possess potent snake venom neutralizing capacity and could potentially be used as an adjuvants for antivenin therapy in case of snakebite envenomation, especially against the local effects of cobra venoms.
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.