Toxic metal implications on agricultural soils, plants, animals, aquatic life and human health

Abstract:Theproblemofenvironmentalpollutionisaglobalconcernasitaffectstheentireecosystem. There is a cyclic revolution of pollutants from industrial waste or anthropogenic sources into the environment, farmlands, plants, livestock and subsequently humans through the food chain. Most of the toxic metal cases in Africa and other developing nations are a result of industrialization coupled with poor effluent disposal and management. Due to widespread mining activities in South Africa, pollution is a common site with devastating consequences on the health of animals and humans likewise. In recent years, talks on toxic metal pollution had taken center stage in most scientific symposiums as a serious health concern. Very high levels of toxic metals have been reported in most parts of South African soils, plants, animals and water bodies due to pollution. Toxic metals such as Zinc (Zn), Lead (Pb), Aluminium (Al), Cadmium (Cd), Nickel (Ni), Iron (Fe), Manganese (Mn) and Arsenic (As) are major mining effluents from tailings which contaminate both the surface and underground water, soil and food, thus affecting biological function, endocrine systems and growth. Environmental toxicity in livestock is traceable to pesticides, agrochemicals and toxic metals. In this review, concerted efforts were made to condense the information contained in literature regarding toxic metal pollution and its implications in soil,water,plants,animals,marine life and human health

Cytotoxic activity of crude extracts from Datura stramonium’s fungal endophytes against A549 lung carcinoma and UMG87 glioblastoma cell lines and LC-QTOF-MS/MS based metabolite profiling

Abstract : Background: Endophytic fungi are a proven source of bioactive secondary metabolites that may provide lead compounds for novel drug discovery. In this study, crude extracts from fungal endophytes isolated from Datura stramonium were evaluated for cytotoxic activity on two human cancer cell lines. Methods: Fungal endophytes were isolated from surface sterilized aerial parts of D. stramonium and identified using molecular, morphological and phylogenetic methods. Ethyl acetate crude extracts from these isolates were evaluated for cytotoxic activity on A549 lung carcinoma and UMG87 glioblastoma cell lines. Metabolite profiling was then performed by liquid chromatography coupled to quadrupole time-of-flight with tandem mass spectrometry (LC-QTOF-MS/MS) for the cytotoxic crude extract. Results: Eleven fungal endophytes were identified from D. stramonium. Significant cytotoxicity was only observed from the crude extract of Alternaria sp. KTDL7 on UMG87 glioblastoma cells (IC50 = 21.49 μg/ml). Metabolite profiling of this crude extract tentatively revealed the presence of the following secondary metabolites: 1,8-dihydroxynaphthalene (1), anserinone B (2), phelligridin B (3), metacytofilin (4), phomopsidin (5) and vermixocin A (6). Compounds 2 and 3 have been shown to be cytotoxic in literature. Conclusion: The findings in this study suggest that the crude extract of Alternaria sp. KTDL7 possesses compound(s) cytotoxic to glioblastoma multiforme cells. Future studies to isolate and characterize the cytotoxic compound(s) from this fungus could result in lead development of a fungal-based drug for glioblastoma multiforme treatment

Antibacterial and anticancer activity and untargeted secondary metabolite profiling of crude bacterial endophyte extracts from cinum macowanii baker leaves

Abstract: This study isolated and identified endophytic bacteria from the leaves of Crinum macowanii and investigated the potential of the bacterial endophyte extracts as antibacterial and anticancer agents and their subsequent secondary metabolites. Ethyl acetate extracts from the endophytes and the leaves (methanol: dichloromethane (1 : 1)) were used for antibacterial activity against selected pathogenic bacterial strains by using the broth microdilution method. The anticancer activity against the U87MG glioblastoma and A549 lung carcinoma cells was determined by the MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxy-phenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay. Bacterial endophytes that were successfully isolated from C. macowanii leaves include Raoultella ornithinolytica, Acinetobacter guillouiae, Pseudomonas sp., Pseudomonas palleroniana, Pseudomonas putida, Bacillus safensis, Enterobacter asburiae, Pseudomonas cichorii, and Arthrobacter pascens. Pseudomonas cichorii exhibited broad antibacterial activity against both Gram-negative and Gram-positive pathogenic bacteria while Arthrobacter pascens displayed the least MIC of 0.0625 mg/mL. Bacillus safensis crude extracts were the only sample that showed notable cell reduction of 50% against A549 lung carcinoma cells at a concentration of 100 μg/mL. Metabolite profiling of Bacillus safensis, Pseudomonas cichorii, and Arthrobacter pascens crude extracts revealed the presence of known antibacterial and/or anticancer agents such as lycorine (1), angustine (2), crinamidine (3), vasicinol (4), and powelline. It can be concluded that the crude bacterial endophyte extracts obtained from C. macowanii leaves can biosynthesize bioactive compounds and can be bioprospected for medical application into antibacterial and anticancer agents

Studies on Solanum mauritianum Scopoli bacterial endophytes and the effects of their crude secondary metabolites on common pathogenic bacteria and resistant human cancer cells

Abstract: Please refer to full text to view abstract.D.Tech. (Biotechnology

Phytochemical screening, elemental analysis and antibacterial investigation of Rhoicissus tomentosa : a medicinal plant used in South African traditional medicine

M.Tech. (Biotechnology)Abstract: Globally medicinal plants play a very significant role in health-promotion and the reduction of disease burden in our communities. Over 80,000 species of such plants and their secondary metabolites including tannins, terpenoids, alkaloids, terpenes, phenolic compounds, glycosides and flavonoids have demonstrated excellent antimicrobial properties in vitro. Phytochemicals constitute over 25 – 50% of all pharmaceutical drugs prescribed globally. In addition, most phytochemicals have antioxidant and anti-carcinogenic properties which are beneficial to humans. Furthermore, the vitamins and other substances in plants play a significant role in protecting the human body against diabetes and heart diseases. Many plants have been the source of many pharmacologically active principles that are now used in medicine, for example, vincristine and vinblastine found in Catharanthus roseus are prescribed for hypertension and can also act as chemotherapeutic drugs against leukemia, Hodgkin’s disease, etc. Nature has provided us with a variety of very useful and important compounds but these have somehow been over looked in recent times and more research attention needs to be given to natural products to explore their many positive therapeutic attributes which is the purpose of this study on Rhoicissus tomentosa. R. tomentosa is a medicinal plant indigenous to Southern Africa. It is a vigorous, evergreen tendril climber with ornamental, vine-like leaves and bunches of purple grape-like fruits. The plant is mainly used by traditional healers to treat fertility related ailments. The rhizomes Rhoicissus tomentosa were analyzed in this study. The dry powdered plant material was first screened for the presence of phytochemicals and the findings revealed the presence of alkaloids, flavonoids, saponins, steroids, reducing sugars and tannins. The ground plant material was subsequently extracted using 100% ethyl acetate and methanol/chloroform (1:1) and pressurized hot water extraction (PHWE) technique. The extracts were analyzed for antimicrobial activity against 14 common human bacterial pathogens using the disc diffusion method and the micro titer plate method and the findings revealed that the extracts showed moderate to high inhibitory activity against most of the test organisms. While different bacterial species were investigated, the most susceptible ones to the rhizome organic solvent extracts were Staphylococcus aureus (MIC 0.063 mg/mL) and Bacillus subtilis (MIC 0.125 mg/mL) and the ones most susceptible to the PHWE extract were Staphylococcus aureus (MIC 1.0 mg/mL) and..