Multidrug resistance (MDR) is a major cause of failure of cancer chemotherapy. Fifty-eight ecdysteroids, herbal analogues of the insect molting hormone and their semisynthetic derivatives, were tested for their activity against L5178 mouse T-cell lymphoma cells (non-MDR) and their subcell line transfected with pHa MDR1/A retrovirus overexpressing the human ABCB1 efflux pump (MDR cell line). The compounds showed very low antiproliferative activities but modulated the efflux of rhodamine 123 mediated by the ABCB1 transporter. Roughly depending on the polarity, mild to strong synergism or antagonism was observed by combining ecdysteroids with doxorubicin, and specific structure-activity relationships were also found. Our results show the effect of ecdysteroids on MDR cancer cells for the first time. Less polar derivatives may serve as valuable leads toward a potent and safe resistance modulator. Biological significance of the resistance-increasing activity of the most abundant phytoecdysteroids including 20-hydroxyecdysone is yet to be clarified.

Bioassay-guided fractionation of the chloroform extract of Tapinella atrotomentosa led to the isolation of four secondary metabolites 1–4. Two of the compounds are lactones—osmundalactone (1) and 5-hydroxy-hex-2-en-4-olide (2)—while 3 and 4 were identified as terphenyl quinones, spiromentins C and B, respectively. The structures of the compounds were established on the basis of NMR and MS spectroscopic analysis. The isolated fungal metabolites were evaluated for their antibacterial activities against several Gram-positive and negative bacteria. In addition, their synergistic effect with cefuroxime against methicillin-resistant Staphylococcus aureus (MRSA) was also evaluated. Compounds 1–3 proved to possess significant antibacterial activity against multiresistant Acinetobacter baumannii and extended-spectrum β-lactamase (ESBL)-producing Escherichia coli. The investigation of the antioxidant effect of the isolated compounds in DPPH and ORAC assays revealed that spiromentins C (3) and B (4) have remarkable antioxidant activity.

Mycochemical study of the mushroom Gymnopus fusipes led to the discovery of two new cyclopeptides. The two compounds, named as gymnopeptides A and B, are unprecedented highly N-methylated cyclic octadecapeptides. Detailed spectroscopic studies, Marfey's analysis, and a preliminary molecular modeling study suggested that both are natural cyclic β hairpins. The isolated compounds exhibited striking antiproliferative activity on several human cancer cell lines, with nanomolar IC50 values.

In this study, 160 organic (n-hexane, chloroform and 50% methanol) and aqueous extracts of 40 mushroom species were submitted to antibacterial screening assay. The antibacterial capacity of 18 species has been examined for the first time. Nineteen extracts of 16 species showed antibacterial effects with moderate to high potential. The extracts of Fistulina hepatica, Tapinella atrotomentosa and Rhodocybe popinalis exhibited not only broad antibacterial spectrum, but also synergistic activity with cefuroxime against MRSA. Our screening study proved that mushroom species are promising sources of potential antimicrobial molecules. The results serve as good starting point for selection of fungal species for detailed pharmacological and chemical investigation.

In the present work, aqueous and organic extracts of 16 Basidiomycetes mushrooms and 1 Ascomycetes mushroom were investigated in vitro for their antiproliferative activity against HeLa (cervix epithelial adenocarcinoma), A431 (skin epidermoid carcinoma), A2780 (ovarian carcinoma), and MCF7 (breast epithelial adenocarcinoma) cells, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. A total of 68 n-hexane, chloroform, 50% methanol, and water extracts of selected species were screened for their potential cell growth inhibitory activity. Our experiments revealed that 7 of 17 species demonstrated notable antiproliferative activity (at least 50% inhibition of cell proliferation) against one or more cell lines. Kuehneromyces mutabilis, Lactarius quietus, and Lentinellus cochleatus, which exerted the highest activity on cancer cells, are considered valuable species in the perspective of further mycochemical studies.

Ten representative Central European phellinoid Hymenochaetaceae species (Phellinus sensu lato) were selected to examine their potential pharmacological activity. In this study 40 organic (n-hexane, chloroform, 50% methanol) and aqueous extracts with different polarities were analyzed for their antimicrobial, antioxidant, and xanthine oxidase (XO)--inhibitory properties. Fomitiporia robusta, Fuscoporia torulosa, Phellopilus nigrolimitatus, and Porodaedalea chrysoloma showed moderate antibacterial activity; Bacillus subtilis ATCC 6633, methicillin-resistant Staphylococcus aureus ATCC 43300, and Moraxella catarrhalis ATCC 43617 were the strains most susceptible to the examined fungal species. The in vitro antioxidant and XO assays demonstrated that most of the selected species possess remarkable antioxidant and XO-inhibitory activities. The water extracts in general proved to be more active antioxidants than organic extracts. In the case of F. torulosa, Ph. Nigrolimitatus, and P. chrysoloma, the results of DPPH tests correlate well with those obtained by oxygen radical absorbance capacity tests; these mushrooms presented high antioxidant activities in both assays. Future studies involving phellinoid Hymenochaetaceae species are planned, which may furnish novel results in terms of the species' pharmacological activity and the specific compounds responsible for the observed activity.

Mushrooms represent a remarkable and yet largely unexplored source of new, biologically active natural products. In this work, we report on the xanthine oxidase (XO) inhibitory activity of 47 wild-growing mushrooms native to Hungary. Aqueous and organic (n-hexane, chloroform, and 50% methanol) extracts of selected mushrooms from different families were screened for their XO inhibitory activities. Among the 188 extracts investigated, the chloroform and 50% methanol fractions proved to be the most effective. Some species exhibited high inhibitory activity, e.g., Hypholoma fasciculare (IC50  =67.76 ± 11.05 µg/mL), Suillus grevillei (IC50  =13.28 ± 1.58 µg/mL), and Tricholoma populinum (IC50  =85.08 ± 15.02 µg/mL); others demonstrated moderate or weak activity. Additional studies are warranted to characterize the compounds responsible for the XO inhibitory activity of mushroom extracts.

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