Efficacy of Willow Herb (<i>Epilobium angustifolium</i> L. and <i>E. parviflorum</i> Schreb.) Crude and Purified Extracts and Oenothein B Against Prostatic Pathogens
Alexia Barbarossa,
Antonio Rosato,
Alessia Carocci,
Sabrina Arpini,
Stefania Bosisio,
Luca Pagni,
Diletta Piatti,
Eleonora Spinozzi,
Simone Angeloni,
Gianni Sagratini,
Gokhan Zengin,
Marco Cespi,
Filippo Maggi,
Giovanni Caprioli
Affiliations
Alexia Barbarossa
Department of Pharmacy-Pharmaceutical Sciences, University of Bari “Aldo Moro”, Via E. Orabona, 4, 70125 Bari, Italy
Antonio Rosato
Department of Pharmacy-Pharmaceutical Sciences, University of Bari “Aldo Moro”, Via E. Orabona, 4, 70125 Bari, Italy
Alessia Carocci
Department of Pharmacy-Pharmaceutical Sciences, University of Bari “Aldo Moro”, Via E. Orabona, 4, 70125 Bari, Italy
Sabrina Arpini
Indena S.p.A., Via Don Minzoni 6, 20090 Settala, Italy
Stefania Bosisio
Indena S.p.A., Via Don Minzoni 6, 20090 Settala, Italy
Luca Pagni
Indena S.p.A., Via Don Minzoni 6, 20090 Settala, Italy
Diletta Piatti
Chemistry Interdisciplinary Project (ChIP) Research Center, School of Pharmacy, University of Camerino, Via Madonna delle carceri, 62032 Camerino, Italy
Eleonora Spinozzi
Chemistry Interdisciplinary Project (ChIP) Research Center, School of Pharmacy, University of Camerino, Via Madonna delle carceri, 62032 Camerino, Italy
Simone Angeloni
Chemistry Interdisciplinary Project (ChIP) Research Center, School of Pharmacy, University of Camerino, Via Madonna delle carceri, 62032 Camerino, Italy
Gianni Sagratini
Chemistry Interdisciplinary Project (ChIP) Research Center, School of Pharmacy, University of Camerino, Via Madonna delle carceri, 62032 Camerino, Italy
Gokhan Zengin
Department of Biology, Science Faculty, Selcuk University, Konya 42130, Turkey
Marco Cespi
Chemistry Interdisciplinary Project (ChIP) Research Center, School of Pharmacy, University of Camerino, Via Madonna delle carceri, 62032 Camerino, Italy
Filippo Maggi
Chemistry Interdisciplinary Project (ChIP) Research Center, School of Pharmacy, University of Camerino, Via Madonna delle carceri, 62032 Camerino, Italy
Giovanni Caprioli
Chemistry Interdisciplinary Project (ChIP) Research Center, School of Pharmacy, University of Camerino, Via Madonna delle carceri, 62032 Camerino, Italy
Background/Objectives: Plants species of the Epilobium genus are traditionally used to treat prostatitis and other urinary tract disorders and are particularly rich in ellagitannins and flavonol 3-O-glycosides. The aim of this work was to evaluate the inhibitory activity of different extracts from E. angustifolium L. and E. parviflorum Schreb. and their major bioactive compound, oenothein B, against a panel of Gram-positive (Enterococcus faecalis ATCC 29212, Enterococcus faecalis BS, Staphylococcus aureus ATCC 25923, Staphylococcus aureus ATCC 29213, and Staphylococcus aureus ATCC 43300) and Gram-negative (Escherichia coli ATCC 25922, Escherichia coli ATCC 35218, Escherichia coli BS, Klebsiella pneumoniae ATCC 13883, Klebsiella pneumoniae ATCC 70063, Klebsiella pneumoniae BS, Proteus mirabilis BS, and Pseudomonas aeruginosa ATCC 27853) bacteria responsible for prostatitis. Methods: Aqueous and ethanolic raw extracts were prepared, and the latter were further purified using the resin AmberliteTM XAD7HP. Then, an HPLC-MS/MS method was developed for the quantification of the marker bioactives and their levels were correlated with the antimicrobial activity. Results: Purified extracts were richer in polyphenols (330.80 and 367.66 mg/g of dry extract for E. angustifolium and E. parvifolium, respectively) than the raw extracts. Oenothein B was the predominant compound in all the extracts (119.98 to 327.57 mg/g of dry extract). The minimum inhibitory concentrations (MICs) in the range of µg/mL indicated significant antibacterial activity, which was higher for the purified extracts and oenothein B (MIC values from 4 to 16 and 8 to 1024 µg/mL on Gram-positive and Gram-negative strains, respectively). Conclusions: These results outline the outstanding potential of E. angustifolium and E. parviflorum extracts and oenothein B as therapeutic alternatives or complementary agents to conventional antibiotic treatments of prostatitis and other urinary tract infections.
