514 COMPARISON OF ANTIBACTERIAL AND ANTIOXIDANT PROPERTIES OF FRUITS AND LEAVES OF BLACKBERRY (RUBUS PLICATUS) AND RASPBERRY (RUBUS IDAEUS) Dorota Grabek-Lejko*, Katarzyna Wojtowicz Address(es): University of Rzeszow, Faculty of Biology and Agriculture, Department of Biotechnology and Microbiology, Zelwerowicza 4, 35-601, Rzeszow, Poland, Phone number: 0048 17 7855438. *Corresponding author: dorobek@o2.pl ABSTRACT Keywords: Blackberry, raspberry, antioxidant activity, antibacterial activity, bioscreen C INTRODUCTION Rubus is one of a hundred genera in the family Rosaceae, subfamily Rosoideae, tribe Potentilleae; there are 250 species of Rubus established worldwide, especially in the northern temperate zone with the majority being indigenous to Europe (Patel et al., 2004). The genus Rubus (raspberry, blackberry) comprises around 700 species (Gudej et al., 2004). The most common species of Rubus naturally occurring throughout Europe and also in Poland are blackberry (Rubusplicatus) and raspberry (Rubusidaeus) (Kurtto et al., 2010; Zając and Zając, 2001). Extracts of the leaves and fruits of Rubus species have been traditionally used for their therapeutic purposes (Patel et al., 2004; Lee et al., 2012). Blackberry leaves have been used for their astringent, antidiarrhoeic, hypoglycemic activities and as an anti-inflammatory agent for the mucous membrane of the oral cavity and throat (Gudej et al., 2004). Blackberry leaves have also antiproliferative activity against cancer cells (Martini et al., 2009). Raspberry leaves (R. idaeus L.) have been commonly used to treat diseases of the alimentary canal, heart and the cardiovascular system. However, they are best known for their health benefits in treating fever, influenza, diabetes, menstrual pain, diarrhea and colic pain. The leaves of raspberry may also be applied externally as antibacterial, anti-inflammatory, sudorific, diuretic and choleretic agents (Gudejet al., 2004). The worldwide popularity of Rubus fruits have increased due to the fact they are considered a healthy and nutritious food, containing many antioxidants, like phenolics, vitamin C, carotenoids, etc. (Lee et al., 2012). Antioxidants present in fruits play an important role in inhibiting and scavenging free radicals, thus providing protection to humans against infections and degenerative diseases like cancer, cardiovascular disease, diabetes and diseases associated with ageing, like Alzheimer’s disease (Grabek-Lejko and Tomczyk-Ulanowska, 2013). Among different bacteria, Staphylococcus aureus is a leading cause of human bacterial infection worldwide, which has outstanding ability to acquire resistance to antibiotics, especially methicillin resistance (MRSA) S. aureus, which is resistant to several antibiotics (multidrug resistance). Epidemics and pandemics of antibiotic resistance S. aureus has arisen in the past 60 years (DeLeo et al., 2010, Otter and French, 2010). Even though pharmacological industries still produce new antibiotics, resistance to these drugs by microorganisms increases and now becoming a global concern (Nascimento et al., 2000). There is a pressing need to develop new and innovative antimicrobial agents. Among the potential sources of new antibacterial agents, plants have long been investigated (Djeussi et al., 2013). The aim of our work was to compare antioxidant activities between two most popular and naturally present in European forests Rubus species: R. plicatus (blackberry) and R. idaeus (raspberry). These abilities were measured in fruit and leaves extracts. According to our knowledge there are many articles about most common Rubusspecies, such as R. idaeus and R. fruticosus. The R. fruticosus refers not to a single species, but is used in the aggregate sense, comprising some 2000 described European species. This is due to difficulty to distinguish Rubus species by their fruits, many species arose as a result of hybridization and apomixis. That’s why in medicine and food processing blackberries are under one name R. fruticosus. However, in Poland there are over 100 species of blackberries, among them R. plicatus occurs most frequently, also in Europe. According to our knowledge there are no data on R. plicatus abilities and in this work there are described for the first time. Another goal of this work is to detect antibacterial activity of tested plants against S. aureus strains – two of them taken from international collections and two isolated in local hospital from patients’ wounds. Among them are methicillin resistant (MRSA) strains. In most articles antibacterial activities were analyzed against S. aureus strains from world collections, but only few described antibacterial activities against strains isolated from patients. MATERIAL AND METHODS Preparation of samples Fruits and leaves of Rubusidaeus (raspberry) and Rubusplicatus (blackberry) were collected from several shrubs and identified during 2011 year in the Southern-Eastern part of Poland, then mixed together. Plants were identified by plant taxonomist Professor Krzysztof Oklejewicz. Fruits were lyophilized, grinded, then 5g of dried fruits were immersed in 150 ml of extraction solution, composed of methanol and water (50:50, v/v). The duration of the extraction was 24h, with agitation 200 rpm at room temperature. Extract was collected and left at 4°C and another part of extraction solution (100 ml) was added. Extraction was conducted over 12 hours, at the same conditions as above. Extracts were combined and made up with methanol solution to final volume 250 ml. Freshly prepared extracts were used for antioxidant and phenolic Two plants – Rubus plicatus and Rubus idaeus were screened for antibacterial activity against Staphylococcus aureus strains, methicillin susceptible (MSSA) and methicillin resistant (MRSA), two from world collection culture and two isolated from patients. All tested extracts from fruits and leaves exhibited antibacterial activity, both against MRSA and MSSA strains. Stronger antibacterial activity had leaves extracts than fruits extracts. The strongest bacterial inhibition was observed against strains from collection culture, lower against strains directly isolated from patients’ wounds. Leaf extract from R. idaeus exhibited stronger antibacterial activities than extracts from R. plicatus leaves. Antioxidant activities and phenolic content were also tested. Generally leaves of two tested plants had about 4-fold higher concentration of phenolics than fruit extracts. Leaves and fruits extracts from R. plicatus exhibited 2.3-fold higher concentration of phenolic compounds than R. idaeus. Also antioxidant activities of R. plicatus extracts were higher than in R. idaeus extracts. The present investigation expresses that plants have great potential as antimicrobial compounds against microorganisms, especially against methicillin resistant strains. Moreover these plants are a good source of antioxidants, especially leaves and fruits of R. plicatus, which can be used as a good exogenous sources of antioxidants in our diet. ARTICLE INFO Received 14. 4. 2014 Revised 7. 5. 2014 Accepted 9. 5. 2014 Published 1. 6. 2014 Regular article