Resveratrol derivatives from Commiphora africana (A. Rich.) Endl. display cytotoxicity and selectivity against several human cancer cell lines

Commiphora africana (A. Rich.) Endl. (Burseraceae) is a medicinal plant widely used in Nigerian ethnomedicine. The in vitro cytotoxicity of the stem bark extract of C. africana and isolated cytotoxic compounds was investigated. Three resveratrol derivatives; (E)-resveratrol 3-O-rutinoside (1), 5-methoxy-(E)-resveratrol 3-O-rutinoside (2) and pinostilbene (3), together with 3-hydroxy-5-methoxybenzoic acid (4) were isolated from the methanol fraction of C. africana. Their structures were determined by extensive analysis of their HREIMS and NMR spectra. The cytotoxicity of the isolated compounds against four human carcinoma cells were determined using the MTT assay. Compound 1 displayed the highest antiproliferative effect on the cell lines, with IC50 values of 16.80, 21.74, 17.89 and 17.44 μM, against MCF7, A549, PC3 and HepG2 human cancer cell lines, respectively. In addition, compounds 1-3 showed low toxicity against normal human prostate cell line, with selectivity indices greater than five across the carcinoma cells, indicating the compounds possess potential in the development of low-toxicity chemotherapeutic agents. These results support the traditional use of this plant in the treatment of cancer

Acridone alkaloids from the stem bark of Citrus aurantium display selective cytotoxicity against breast, liver, lung and prostate human carcinoma cells

Ethnopharmacological relevance: Citrus aurantium L. (Rutaceae) is used, either singly or as a part of a polyherbal preparation, in Nigerian traditional medicine for the management of cancer and inflammatory diseases. Currently, there is a dearth of knowledge demonstrating its anticancer potential. Aim of the study: This study was carried out to determine the in vitro cytotoxicity of the crude extract of the stem bark of C. aurantium, identify and isolate the bioactive constituents and to establish the cytotoxicity of such constituents. Material and Methods The powdered bark of C. aurantium was extracted with methanol at room temperature (25-34 °C) and the crude extract was partitioned successively, with nhexane, dichloromethane (DCM) and methanol. Amongst the fractions, the DCM fraction was the most active and compounds were isolated from this fraction using several chromatographic techniques. The structures of the isolated compounds were elucidated by spectroscopic means (mass spectrometry, one-dimensional and two-dimensional nuclear magnetic resonance). The cytotoxicity of the extract, and the isolated compounds were evaluated by the MTT (3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium) assay against four human cancer cell lines: A549 (lung), HepG2 (liver), MCF7 (breast) and PC3 (prostate). The selectivity of the isolated compounds was assessed using the normal human prostate epithelium cells (PNT2). Results and Discussion: Of the three plant fractions, the DCM fraction showed significant cytotoxicity, with its highest activity against A549 cells (IC50 = 3.88 µg/mL) and the least activity on HepG2 cells (IC50 = 5.73 µg/mL). Six acridone alkaloids: citrusinine-I (1), citracridone-I (2), 5-hydroxynoracronycine (3), natsucitrine-I (4), glycofolinine (5) and citracridone-III (6), were isolated from the DCM fraction of C. aurantium. The isolated compounds demonstrated potent to moderate cytotoxicity ((IC50 = 12.65 – 50.74 µM) against the cancer cells under investigation. It is noteworthy that the compounds exerted cytotoxicity at least four times more selective towards the carcinoma cells than the PNT2 cells. Conclusion: The results obtained from this study have provided some evidence for the ethnomedicinal use of C. aurantium against cancer and the acridone alkaloids present in its stem bark, have appeared to be responsible for this effect. Further research to explore the underlying molecular mechanism of the isolated acridone alkaloids is needful

Cytotoxicity evaluation of sixteen Nigerian medicinal plant extracts using the human rhabdomyosarcoma cell line

As part of our evaluation of plants from the Nigerian ethnobotany,sixteen extracts from fourteen medicinal plants were evaluated for toxicity and inhibition of tumour cell growth using human  rhabdomyosarcoma(RD) cell line. The plant samples were extracted by maceration in methanol at room temperature and were investigated for cytotoxicactivity. The ability of each extracts to induced cell death in tissue culture was evaluated by colorimetric method using MTT dye (3-[4, 5-dimethylthiazol–2-yl]-2,5-diphenyltetrazolium bromide) and cyclophosphamide was used as control. Cell death at 50% (CC50) was evaluated for all the extracts. Fourteen of the assessed extracts were cytotoxic (CC50< 20µg/mL) against RD cell, meanwhile extracts from four of the plants, namely; Parquetina nigresence (rb) Thoningia sanguinea (f) Khaya  senegalensis (l) Sida acuta (a) were not cytotoxic(CC50> 20µg/mL). Methanol extracts of Quassia africana and Quassia amara stembark possessed the most significant cytotoxic activity (CC50 = 0.09 and 0.08 µg/mL, respectively)against RD cancer cell andactivity significantly correlated with that of the control drug  cyclophosphamide which had a CC50 of 1.80 µg/mL. Conclusively, the results of the present study indicatethat selected plants demonstrated awide range of cytotoxic activities. This will be of tremendous assistance in assesssing the safety of the medicinal plants and also give direction for future anticancer drug development