The Genus Echinops: Phytochemistry and Biological Activities: A Review

Sesquiterpenoids, and specifically sesquiterpene lactones from Asteraceae, may play a highly significant role in human health, both as part of a balanced diet and as pharmaceutical agents, due to their potential for the treatment of cardiovascular disease and cancer. This review highlights the role of sesquiterpene lactones endogenously in the plants that produce them, and explores mechanisms by which they interact in animal and human consumers of these plants. Several mechanisms are proposed for the reduction of inflammation and tumorigenesis at potentially achievable levels in humans. Plants can be classified by their specific array of produced sesquiterpene lactones, showing high levels of translational control. Studies of folk medicines implicate sesquiterpene lactones as the active ingredient in many treatments for other ailments such as diarrhea, burns, influenza, and neurodegradation. In addition to the anti-inflammatory response, sesquiterpene lactones have been found to sensitize tumor cells to conventional drug treatments. This review explores the varied ecological roles of sesquiterpenes in the plant producer, depending upon the plant and the compound. These include allelopathy with other plants, insects, and microbes, thereby causing behavioural or developmental modification to these secondary organisms to the benefit of the sesquiterpenoid producer. Some sesquiterpenoid lactones are antimicrobial, disrupting the cell wall of fungi and invasive bacteria, whereas others protect the plant from environmental stresses that would otherwise cause oxidative damage. Many of the compounds are effective due to their bitter flavor, which has obvious implications for human consumers. The implications of sesquiterpenoid lactone qualities for future crop production are discussed.

This study was conducted to document and evaluate knowledge on medicinal plant use by Sheko ethnic group in Southwest Ethiopia. Interviews and ranking exercises were the main methods employed to collect the ethnobotanical data. Fidelity level (FL) values were calculated for claimed Sheko medicinal plants to estimate their healing potentials. Seventy-one Sheko medicinal plants were reported, the majority of which were used to treat skin and gastro-intestinal ailments. Ocimum lamiifolium, Phytolacca dodecandra, Amaranthus dubius and Amaranthus graecizans were the medicinal plants assigned with the highest FL values, a possible indication of their better healing potential. The majority of Sheko medicinal plants were found to be herbs, and leaf was the most preferred plant part in remedy preparations. The study indicated that men, older people and illiterate ones had better knowledge of medicinal plants use as compared to women, younger people and literate ones, respectively. The study showed that the Sheko people have rich knowledge of medicinal plant use. This knowledge is however, currently threatened mainly due to acculturation. Awareness should thus be created among Sheko community by concerned bodies regarding the usefulness of their medical practice. The efficacy and safety of the claimed medicinal plants need to be evaluated before recommending them for a wider use with priority given to those with high fidelity level values. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Several medicinal plants and spices are used traditionally to treat cancers in Cameroon. Methanol extracts from thirty-four spices and plants, with related ethnobotanical use were investigated for their in vitro cytotoxicity on the human pancreatic cancer cell line MiaPaCa-2, leukemia CCRF-CEM cells and their multidrug resistant (MDR) subline CEM/ADR5000, and the normal human umbilical vein endothelial cells (HUVECs). In addition the anti-angiogenic properties of the most active extracts were investigated. The MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay was used for cytotoxic studies and the CAM-assay (chicken-chorioallantoic-membrane-assay) for anti-angiogenesis test. The results of the cytotoxicity tests indicated that, when tested at 20 μg/ml, extracts from Xylopia aethiopica, Echinops giganteus, Imperata cylindrica, Dorstenia psilirus and Piper capense were able to inhibit more that 50% the proliferation of the three tested cancer cells (MiaPaCa-2, CEM/ADR5000 CCRF-CEM). The lowest IC(50) values of 6.86 μg/ml on MiaPaCa-2 and 3.91 μg/ml on CCRF-CEM cells were obtained with X. aethiopica, while the corresponding value of 6.56 μg/ml was obtained with P. capense on CEM/ADR5000 cells. Against leukemia cells, no cross-resistance was observed with I. cylindrica, P. capense and Zinziber officinalis. Extracts from D. psilirus and E. giganteus were able to inhibit angiogenesis by more than 50% in quail embryo. The overall results of the present study provide supportive data on the use of some Cameroonian plants for cancer treatment. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.