Multiple readout assay for hormonal (androgenic and antiandrogenic) and cytotoxic activity of plant and fungal extracts based on differential prostate cancer cell line behavior

ETHNOPHARMACOLOGICAL RELEVANCE

Prostate cancer is one of the most diagnosed forms of cancer among men in western regions. Many traditional applications or phytotherapeutic concepts propose to inhibit the proliferation of prostate cancer cells. In order to detect influences of plant or fungal extracts and derived fractions on androgen receptor signaling pathways, a differentiating cell proliferation assay was established, which enables the simultaneous detection of hormonal and cytotoxic effects.

MATERIAL AND METHODS

The well characterized prostate cancer cell lines LNCaP and PC-3 were used in a multiple readout assay. In all, 186 fractions of 23 traditionally used organisms were screened regarding their effects on proliferation of the two prostate cancer cell lines. The fractions were prepared by accelerated solvent extraction followed by gradient extrography. Extracts of the potential hormonally active plants Cibotium barometz, Heteropterys chrysophylla, and Sideroxylon obtusifolium (= Bumelia sartorum) were phytochemically investigated.

RESULTS

Fractions from Cibotium barometz, Cortinarius rubellus, Cyrtomium falcatum, Heteropterys chrysophylla, Nephrolepis exaltata, Salvia miltiorrhiza, Sideroxylon obtusifolium, Trichilia emetica, and Trimeria grandifolia exhibited hormonal influences on prostate cancer cells. Cytotoxic activity towards human cell lines was detected for the first time for fractions from Aglaia spectabilis (A. gigantea), Nephrolepis exaltata and Cortinarius brunneus.

CONCLUSIONS

The differential behavior of the two prostate cancer cell lines allows the discrimination between potential androgenic or antiandrogenic activities and effects on the estrogen or glucocorticoid receptor as well as cytotoxic activities. The combined cell lines assay can help to assess the biological activities of material used in traditional medicine.

Antimicrobial, Antioxidant, and Cytotoxic Activities of the Essential Oil of Tarchonanthus camphoratus

The leaf essential oil of Tarchonanthuscamphoratus(As teraceae) was obtained by hydrodistillation and analyzed by GC-MS. Fifty-six components were characterized, representing 94.2% of the total oil with oxygenated monoterpenes (48.3%) and oxygenated sesquiterpenes (32.7%) as the major groups. The principal constituents were identified as endo-fenchol (21.2%), trans-pinene hydrate (8.8%), caryophyllene oxide (7.5%), α-terpineol (6.4%), τ-cadinol (6.4%), and α-cadinol (5.2%). The essential oil was evaluated for its antimicrobial activity using a disc diffusion assay resulting in the moderate inhibition of a number of common human pathogenic bacteria, including methicillin-resistant Staphylococcus aureus(MRSA) and the yeast Candida albicans. The inhibition zones varied from 10 to 14mm/disc. Furthermore, the antioxidant capacity of the essential oil was examined using an in vitroradical scavenging activity test. The T. camphoratus essential oil scavenged 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), resulting in an IC50value of 5.6 mg/mL. At concentrations of 100 and 50μg/mL, the oil showed cytotoxic activity, with growth inhibition of 59.1% (±4.2), and 16.2% (±8.7) against HT29 tumor cells (human colonic adenocarcinoma cells), respectively(IC50 = 84.7 ± 7.5 μg/mL).

Chemical composition, antimicrobial, antioxidant and cytotoxic activity of essential oils of Plectranthus cylindraceus and Meriandra benghalensis from Yemen

The chemical composition, antimicrobial, antioxidant and cytotoxic activities of the essential oils isolated from the leaves of Plectranthus cylindraceus Hoechst. ex. Benth. (EOPC) and Meriandra benghalensis (Roxb.) Benth. (EOMB) were investigated. Sixteen compounds were identified in P. cylindraceus oil representing 94.5% of the oil content with thymol (68.5%), terpinolene (5.3%), beta-selinene (4.7%), beta-caryophyllene (4.0%), delta-cadinol (2.1%), and arcurcumene (1.7%) as the major compounds. In M. benghalensis oil, 12 compounds were identified, which made up 82.0% of the total oil. The most abundant constituents were camphor (43.6%), 1,8-cineole (10.7%), alpha-eudesmol (5.8%), caryophyllene oxide (5.8%), camphene (5.3%) and bomeol (3.4%). The antimicrobial activities of both oils were evaluated against five microorganisms with the disc diffusion test, the broth micro-dilution method and a semiquantitative bioautographic test. The most sensitive microorganisms for P. cylindraceus oil were S. aureus, B. subtilis, and C. albicans with inhibition zones of 38, 42, and 43 mm and MIC values of 0.39, 0.18, and, 0.18 microL/mL, respectively. M. benghalensis oil showed weak to moderate activity against the tested microorganisms. 2,2-Diphenyl-l-picrylhydrazyl (DPPH) assay was employed to study the potential antioxidant activities of both oils. The antioxidant activity of P. cylindraceus oil (IC50 34.5 microg/mL) appeared to be higher than that of M. benghalensis oil (IC50 935 microg/mL). At a concentration of 100 microg/mL, EOMB showed a stronger cytotoxic activity, with growth inhibition of 71% against HT29 tumor cells, than EOPC (18%).

Chemical Composition, Antimicrobial, Antioxidant and Cytotoxic Activity of Essential Oils of Plectranthus cylindraceus and Meriandra benghalensis from Yemen

The chemical composition, antimicrobial, antioxidant and cytotoxic activities of the essential oils isolated from the leaves of Plectranthus cylindraceus Hoechst. ex. Benth. (EOPC) and Meriandra benghalensis (Roxb.) Benth. (EOMB) were investigated. Sixteen compounds were identified in P. cylindraceus oil representing 94.5% of the oil content with thymol (68.5%), terpinolene (5.3%), β-selinene (4.7%), β-caryophyllene (4.0%), δ-cadinol (2.1%), and ar-curcumene (1.7%) as the major compounds. In M. benghalensis oil, 12 compounds were identified, which made up 82.0% of the total oil. The most abundant constituents were camphor (43.6%), 1,8-cineole (10.7%), α-eudesmol (5.8%), caryophyllene oxide (5.8%), camphene (5.3%) and borneol (3.4%). The antimicrobial activities of both oils were evaluated against five microorganisms with the disc diffusion test, the broth micro-dilution method and a semiquantitative bioautographic test. The most sensitive microorganisms for P. cylindraceus oil were S. aureus, B. subtilis, and C. albicans with inhibition zones of 38, 42, and 43 mm and MIC values of 0.39, 0.18, and, 0.18 μL/mL, respectively. M. benghalensis oil showed weak to moderate activity against the tested microorganisms. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay was employed to study the potential antioxidant activities of both oils. The antioxidant activity of P. cylindraceus oil (IC50 34.5 μg/mL) appeared to be higher than that of M. benghalensis oil (IC50 935 μg/mL). At a concentration of 100 μg/mL, EOMB showed a stronger cytotoxic activity, with growth inhibition of 71% against HT29 tumor cells, than EOPC (18%).

The multiple multicomponent approach to natural product mimics: tubugis, N-substituted anticancer peptides with picomolar activity

The synthesis of a new generation of highly cytotoxic tubulysin analogues (i.e., tubugis) is described. In the key step, the rare, unstable, and synthetically difficult to introduce tertiary amide-N,O-acetal moiety required for high potency in natural tubulysins is replaced by a dipeptoid element formed in an Ugi four-component reaction. Two of the four components required are themselves produced by other multicomponent reactions (MCRs). Thus, the tubugis represent the first examples of the synthesis of natural-product-inspired compounds using three intertwined isonitrile MCRs.

First total synthesis of tubulysin B

The first total synthesis of tubulysin B is described. The aziridine route to tubuphenylalanine (Tup) of the tubulysin D/U-series could not be transferred to the synthesis of tubutyrosine (blue moiety). Therefore, tubutyrosine (Tut) was synthesized by a Wittig olefination/diastereoselective catalytic reduction sequence. Interestingly, the C-2 epimer of tubulysin B has a cytotoxic activity almost identical to the natural diastereomer.