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Anticancer and antimicrobial activities of some antioxidant-rich cameroonian medicinal plants.

Tamokou Jde D, Chouna JR, Fischer-Fodor E, Chereches G, Barbos O, Damian G, Benedec D, Duma M, Efouet AP, Wabo HK, Kuiate JR, Mot A, Silaghi-Dumitrescu R - PLoS ONE (2013)

Bottom Line: The AOA of emodin was significantly higher than that of 3-geranyloxyemodin and 2-geranylemodin for both TEAC and HAPX methods.The lowest IC(50) values (i.e., highest cytotoxicity) were found for the extracts of Vismia laurentii, Psorospermum febrifugum, Pentadesma butyracea and Ficus asperifolia.Emodin is more toxic compared to the whole extract, 3-geranyloxyemodin and 2-geranylemodin.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Chemical Engineering, Babes-Bolyai University, Cluj-Napoca, Romania.

ABSTRACT
Traditional remedies have a long-standing history in Cameroon and continue to provide useful and applicable tools for treating ailments. Here, the anticancer, antimicrobial and antioxidant activities of ten antioxidant-rich Cameroonian medicinal plants and of some of their isolated compounds are evaluated.The plant extracts were prepared by maceration in organic solvents. Fractionation of plant extract was performed by column chromatography and the structures of isolated compounds (emodin, 3-geranyloxyemodin, 2-geranylemodin) were confirmed spectroscopically. The antioxidant activity (AOA) was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) bleaching method, the trolox equivalent antioxidant capacity (TEAC), and the hemoglobin ascorbate peroxidase activity inhibition (HAPX) assays. The anticancer activity was evaluated against A431 squamous epidermal carcinoma, WM35 melanoma, A2780 ovary carcinoma and cisplatin-resistant A2780cis cells, using a direct colorimetric assay. The total phenolic content in the extracts was determined spectrophotometrically by the Folin-Ciocalteu method. Rumex abyssinicus showed the best AOA among the three assays employed. The AOA of emodin was significantly higher than that of 3-geranyloxyemodin and 2-geranylemodin for both TEAC and HAPX methods. The lowest IC(50) values (i.e., highest cytotoxicity) were found for the extracts of Vismia laurentii, Psorospermum febrifugum, Pentadesma butyracea and Ficus asperifolia. The Ficus asperifolia and Psorospermum febrifugum extracts are selective against A2780cis ovary cells, a cell line which is resistant to the standard anticancer drug cisplatin. Emodin is more toxic compared to the whole extract, 3-geranyloxyemodin and 2-geranylemodin. Its selectivity against the platinum-resistant A2780cis cell line is highest. All of the extracts display antimicrobial activity, in some cases comparable to that of gentamycin.

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Cluster tree of the EPR spectra profiles.Dendogram is obtained using Ward’s linkage showing grouping of the plant extracts according to their EPR spectrum profiles. Group A: subgroup 1 Rumex bequaertii, Rumex abyssinicus, Dichrostachys glomerata (labelled in black), subgroup 2: Tectona grandis, Paullinia pinnata, Hibiscus asper (labelled in grey, on the right); Group B: Pentadesma butyracea, Vismia laurentii, Ficus asperifolia, Psorospermum febrifugum (labelled in grey, on the left) (details on EPR spectra profile in Figure 6).
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pone-0055880-g007: Cluster tree of the EPR spectra profiles.Dendogram is obtained using Ward’s linkage showing grouping of the plant extracts according to their EPR spectrum profiles. Group A: subgroup 1 Rumex bequaertii, Rumex abyssinicus, Dichrostachys glomerata (labelled in black), subgroup 2: Tectona grandis, Paullinia pinnata, Hibiscus asper (labelled in grey, on the right); Group B: Pentadesma butyracea, Vismia laurentii, Ficus asperifolia, Psorospermum febrifugum (labelled in grey, on the left) (details on EPR spectra profile in Figure 6).

Mentions: It is known that treatment of phenolic compounds with alkali in aerobic conditions leads to stable semiquinone anionic radicals which can be detected using EPR spectroscopy. We have previously shown that treatment of natural extracts with a strong hydroxide solution leads to informative EPR signals which may vary in intensity and shape according to the chemical composition [71]. EPR spectra obtained in this manner for the studied extracts are plotted in Figure 6. Using cluster analysis (Ward’s method, using Statistica 8 software) applied on the first five factor scores obtained by applying PCA on the digitized EPR spectra which were previously normalized, according to the steps similarly described in [53], the spectra constitute two large groups: A (wide signals with various g values) and B (sharper signals with close g values but different intensities) (Figure 7). Group A can be further divided into two subgroups, based on their intensities (very high intensity and low intensity (inset in Figure 6)). Most probably, group B does not involve phenolic acids, p-quinoid structures similar to hydroquinone or glycosides of various phenolics since they have wider spectra (Figure 6C), but rather flavonoids such as luteolin and quercetin or other unidentified species. The difference in intensities may come both from phenolic content (content of radical generated) and chemical species (due to radical stability). Interestingly, the three isolated compounds yield very weak signals in EPR spectra, presumably due to a high instability and/or to a slow generation.


Anticancer and antimicrobial activities of some antioxidant-rich cameroonian medicinal plants.

Tamokou Jde D, Chouna JR, Fischer-Fodor E, Chereches G, Barbos O, Damian G, Benedec D, Duma M, Efouet AP, Wabo HK, Kuiate JR, Mot A, Silaghi-Dumitrescu R - PLoS ONE (2013)

Cluster tree of the EPR spectra profiles.Dendogram is obtained using Ward’s linkage showing grouping of the plant extracts according to their EPR spectrum profiles. Group A: subgroup 1 Rumex bequaertii, Rumex abyssinicus, Dichrostachys glomerata (labelled in black), subgroup 2: Tectona grandis, Paullinia pinnata, Hibiscus asper (labelled in grey, on the right); Group B: Pentadesma butyracea, Vismia laurentii, Ficus asperifolia, Psorospermum febrifugum (labelled in grey, on the left) (details on EPR spectra profile in Figure 6).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3569468&req=5

pone-0055880-g007: Cluster tree of the EPR spectra profiles.Dendogram is obtained using Ward’s linkage showing grouping of the plant extracts according to their EPR spectrum profiles. Group A: subgroup 1 Rumex bequaertii, Rumex abyssinicus, Dichrostachys glomerata (labelled in black), subgroup 2: Tectona grandis, Paullinia pinnata, Hibiscus asper (labelled in grey, on the right); Group B: Pentadesma butyracea, Vismia laurentii, Ficus asperifolia, Psorospermum febrifugum (labelled in grey, on the left) (details on EPR spectra profile in Figure 6).
Mentions: It is known that treatment of phenolic compounds with alkali in aerobic conditions leads to stable semiquinone anionic radicals which can be detected using EPR spectroscopy. We have previously shown that treatment of natural extracts with a strong hydroxide solution leads to informative EPR signals which may vary in intensity and shape according to the chemical composition [71]. EPR spectra obtained in this manner for the studied extracts are plotted in Figure 6. Using cluster analysis (Ward’s method, using Statistica 8 software) applied on the first five factor scores obtained by applying PCA on the digitized EPR spectra which were previously normalized, according to the steps similarly described in [53], the spectra constitute two large groups: A (wide signals with various g values) and B (sharper signals with close g values but different intensities) (Figure 7). Group A can be further divided into two subgroups, based on their intensities (very high intensity and low intensity (inset in Figure 6)). Most probably, group B does not involve phenolic acids, p-quinoid structures similar to hydroquinone or glycosides of various phenolics since they have wider spectra (Figure 6C), but rather flavonoids such as luteolin and quercetin or other unidentified species. The difference in intensities may come both from phenolic content (content of radical generated) and chemical species (due to radical stability). Interestingly, the three isolated compounds yield very weak signals in EPR spectra, presumably due to a high instability and/or to a slow generation.

Bottom Line: The AOA of emodin was significantly higher than that of 3-geranyloxyemodin and 2-geranylemodin for both TEAC and HAPX methods.The lowest IC(50) values (i.e., highest cytotoxicity) were found for the extracts of Vismia laurentii, Psorospermum febrifugum, Pentadesma butyracea and Ficus asperifolia.Emodin is more toxic compared to the whole extract, 3-geranyloxyemodin and 2-geranylemodin.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry and Chemical Engineering, Babes-Bolyai University, Cluj-Napoca, Romania.

ABSTRACT
Traditional remedies have a long-standing history in Cameroon and continue to provide useful and applicable tools for treating ailments. Here, the anticancer, antimicrobial and antioxidant activities of ten antioxidant-rich Cameroonian medicinal plants and of some of their isolated compounds are evaluated.The plant extracts were prepared by maceration in organic solvents. Fractionation of plant extract was performed by column chromatography and the structures of isolated compounds (emodin, 3-geranyloxyemodin, 2-geranylemodin) were confirmed spectroscopically. The antioxidant activity (AOA) was determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) bleaching method, the trolox equivalent antioxidant capacity (TEAC), and the hemoglobin ascorbate peroxidase activity inhibition (HAPX) assays. The anticancer activity was evaluated against A431 squamous epidermal carcinoma, WM35 melanoma, A2780 ovary carcinoma and cisplatin-resistant A2780cis cells, using a direct colorimetric assay. The total phenolic content in the extracts was determined spectrophotometrically by the Folin-Ciocalteu method. Rumex abyssinicus showed the best AOA among the three assays employed. The AOA of emodin was significantly higher than that of 3-geranyloxyemodin and 2-geranylemodin for both TEAC and HAPX methods. The lowest IC(50) values (i.e., highest cytotoxicity) were found for the extracts of Vismia laurentii, Psorospermum febrifugum, Pentadesma butyracea and Ficus asperifolia. The Ficus asperifolia and Psorospermum febrifugum extracts are selective against A2780cis ovary cells, a cell line which is resistant to the standard anticancer drug cisplatin. Emodin is more toxic compared to the whole extract, 3-geranyloxyemodin and 2-geranylemodin. Its selectivity against the platinum-resistant A2780cis cell line is highest. All of the extracts display antimicrobial activity, in some cases comparable to that of gentamycin.

Show MeSH
Related in: MedlinePlus