Alkanna orientalis (L.) Boiss. plant isolated cultures and antimicrobial activity of their extracts: phenomenon, dependence on different factors and effects on some membrane-associated properties of bacteria

Abstract

Herbal medicine requires searching for new sources with antimicrobial activity. Alkanna sp. (Boraginaceae) is widely used in medicine due to detoxification and antibacterial effects. The aim of this study was to obtain Alkanna orientalis (L.) Boiss. plant callus extracts, to investigate antimicrobial activity of extracts against bacteria and yeast and to reveal responsible mechanisms. Callus tissue cultures have been obtained using different nutrient media. Antimicrobial activity and minimal inhibitory concentrations (MIC) were determined by the methods of extract diffusion in agar and dilution using different test-microorganisms. Quantity and quality of naphthoquinones were determined using spectrophotometric and high performance liquid chromatographic analyses. H ? /K ? exchange by whole cells was assayed using selective electrodes, ATPase activity and SH-groups number of membrane vesicles-by spectrophotometric methods. It was revealed that callus extracts containing naphthoquinones (0.19 ± 0.01 %) possessed bacteriostatic activity against gram-positive bacteria including pathogenic ones (MIC were 125-750 lg/mL -1 ), and bactericidal activity against lactic acid bacteria (Lactobacillus acidophilus, L. rhamnosus) (MIC was 250 lg/mL). MIC against Enterococcus hirae was 250 lg/mL of callus extract or 31.25 lg/ mL of shikonin. It depended on the medium content, cultivation duration and the activity remained for 10-11 years. Moreover, intact root extracts inhibited H ?

Antimicrobial activity of some plant materials used in Armenian traditional medicine

“…Mothana and Lindequist [31] showed that methanol extracts were more active than chloroform extracts which confirms our data. In our study aqueous extracts have shown poor antimicrobial activities at tested concentrations which coincides with literature data [3, 10, 31–33]. …”

“…It is well known that about quarter part of current medications is derived from compounds of plant origin [1, 7]. Plant-derived compounds could have other target sites than traditional antimicrobials and subsequently having different mechanisms of action against microbes [6, 8–10]. …”

“…However, only a small part of them were investigated for antimicrobial activity [4, 10, 11]. People started to use plant materials to treat infectious diseases since ancient times even without any knowledge on their causative agents [12].…”

In Vitro Evaluation of Antimicrobial Activity of Roots Extracts of Capparis spinosa L. And Important Medicinal Plant

“…Rates (2001) reported that quarter part of current medications is derived from compounds of plant origin. Ahmad and Beg (2001); Petrosyan et al;(2015) reported that plant derived compounds could have other target sites than traditional antimicrobials and subsequently having different mechanism of action against microbes. (2010); Rajesh et al;(2010); Cowan (2012); Upadhyaya et al; reported that plant secondary metabolites have different groups such as Phenolics, and poly phenols (flavonoids, quinines, tannins, coumarins,), terpenoids, alkaloids, lectins and polypeptides.…”

“…We have a long list of medicinal plants but only few have been evaluated in vitro for their antimicrobial activities in vitro (Borris 1996;Petrosyan et al;2015). From the ancient times, people started to use plant materials to treat infectious disease, to heal the cuts and wound without knowing about the causative agents present among the plants.…”