A micro-Raman spectroscopic investigation of leukemic U-937 cells treated with Crotalaria agatiflora Schweinf and the isolated compound madurensine

Abstract

In South Africa traditional medicine plays an important role in primary health care and therefore it is very important that the medicinal use of plants is scientifically tested for toxicity and effectiveness. It was established that the ethanolic extract of the leaves of Crotalaria agatiflora, as well as the isolated compound madurensine, is moderately toxic against leukemic U-937 cells. The investigation showed that micro-Raman spectroscopy has great promise to be used for initial screening of samples to determine the effects of different treatments on cancerous cell lines together with conventional methods. The results highlight the fact that for many natural products used for medicinal purposes, the therapeutic effect of the crude plant extract tends to be significantly more effective than the particular action of its individual constituents. Graphical abstractLeukemic U-937 cells were treated with different concentrations of the ethanolic extract of Crotalaria agatiflora subspp. agatiflora and the isolated pyrrolizidine alkaloid, madurensine.Different biochemical responses were observed with micro-Raman spectroscopy after treatments. Highlights Crotalaria agatiflora Schweinf has an ethnobotanic use against cancer.  An ethanolic extract of the plant was tested against leukemic U-937 cells.  Raman spectra showed changes in cell morphology and biochemical constituents.  Crude plant extracts might be more bioactive than isolated compounds.  Raman spectroscopy has potential as an initial screening tool in phytomedicine.

Cellular injury evidenced by impedance technology and infrared microspectroscopy

“…Medicinal plants have long been studied for their effectiveness in treating cancer. Crude extracts of medicinal plants are more potent cytotoxins because of the synergy of the many phytochemicals found in the mixture [24]. The cell death inducer in this investigation was a leaves extract of Plectranthus ciliatus.…”

“…In a previous study, we found that Raman micro-spectroscopy could be used to pre-screen a plant extract for its anticancer activity against the proliferation of leukemic U-937 cells [24].…”

High throughput toxicity screening and intracellular detection of nanomaterials

“…CRM imaging was used to follow the different stages of the cell cycle,36 DNA condensation in late stages of apoptosis and also for the assessment of cell viability 37, 38. DNA damage, lipid changes, and protein denaturation were analyzed as a response to drugs and chemicals 39, 40. However, the spatial resolution and sensitivity of CRM are limited compared with TEM which typically has a threshold of ~60 nm 41…”

Investigating the effects of Pentoxifylline on human breast cancer cells using Raman spectroscopy

“…Correction for spectral di®erences due to relative intensity changes was performed by vector normalization. First derivative and vector normalized spectra were interpolated in 800-1800 cm À1 region 16,22,26,28,[31][32][33] and used as input for multivariate analysis by principal component-linear discriminant analysis (PC-LDA). PC-LDA models were then validated by leave-one-out cross-validation (LOOCV).…”

“…19 It has the advantage of having minimum interference from water bands which makes it more appropriate for biomedical applications 20 and provides an easy, chemicalfree and nondestructive method for studying cells in vitro, cell drug interactions as well as for distinguishing neoplastic from normal tissues. [21][22][23][24][25][26][27][28][29][30][31][32] Each tumor is composed of several distinct cell populations and thus the potential and e±cacy of chemotherapy is largely governed by the presence of most chemosensitive or rather least resistant cell populations. Identi¯cation of a resistant/sensitive phenotype in cancer cells from the patients can enhance the e±cacy of therapy.…”