Ethnobotanical relevance: Piper guineense occurs commonly in West Africa where it is used for fungal infections instead of the costly and not always accessible conventional antifungals. Fungal, yeast-based diseases are common in West-Africa especially among those living with HIV/AIDS, and thus this study was performed in Imo state, South-Eastern Nigeria, where P. guineense is predominantly used for the treatment of fungal diseases, such as skin rashes, oral thrush and vaginosis. Aim of study: The scarce number of previous studies on the documentation of the traditional uses of P. guineense extracts for the treatment of fungal infections in Nigeria prompted this survey. The investigation focused on how traditional healers recognize and diagnose fungal infections, how P. guineense is collected, on the various parts used for the treatments, methods of preparations, administrations and treatments. In addition, an in vitro anti fungal screening of P. guineense fruit and leaf extracts of various polarities, and piperine and piperlongumine, representing the main constituents in these extracts, were performed. Methods: A house to house ethnobotanical survey was conducted using questionnaires. Twenty traditional medical practitioners (TMP) and herb sellers from ten villages were interviewed. Four human pathogenic strains of yeast and Cryptococcus neoformans, a yeast-like basidiomycete causing meningitis in immunocompromised individuals, were used for the antifungal screening. Results: The traditional medical practitioners (TMP) and herb sellers explained that the leaves and fruits are the most commonly used plant parts for the treatments. The oral intake of the extracts in locally produced bamboo alcohol (Kai-kai) is the most common method of administration. In accordance with these recorded traditional uses, we found that extracts of P. guineense were growth inhibitory against the fungal strains with MIC values ranging from 39 to 2500 g/mL. The lowest MIC value of 39 g/mL was recorded for a methanol fruit extract against Candida albicans, C. glabrata and C. tropicalis. In addition, ethanol and hexane fruit extracts were effective against the growth of C. albicans and C. glabrata, respectively, with a MIC of 78 g/mL. Piperlongumine and piperine were active against C. albicans with MIC values of 39 and 78 g/mL respectively. Conclusion: P. guineense fruit and leaf extracts, as well as their piperamide alkaloid constituents piperine and piperlongumine, have interesting antifungal properties and could have potential as new antifungal scaffolds. Our results warrant further in-depth investigations to isolate and characterize piperamide alkaloids and other compounds responsible for the antifungal activity in the extracts.

BACKGROUND It is important to find plant materials that can inhibit the growth of Listeria monocytogenes and other food-spoiling bacteria both in vitro and in situ. The aim of the study was to compare antibacterial and antioxidative activity of selected plant-ethanol infusions: leaves and berries of blackcurrant (Ribes nigrum L.), berries of chokeberry (Aronia melanocarpa (Michx.) Elliott) and blue honeysuckle (Lonicera caerulea L. var. edulis); petioles and dark and light roots of garden rhubarb (Rheum rhaponticum L.) for potential use in food matrices as antibacterial and antioxidative additives. RESULTS The strongest bacterial growth inhibition was observed in 96% ethanol infusions of the dark roots of rhubarbs. In 96% ethanol, nine out of ten studied plant infusions had antibacterial effect against L. monocytogenes, but in 20% ethanol only the infusions of dark rhubarb roots had a similar effect. Chokeberry and other berries had the highest antioxidative activity, both in 20% and 96% ethanol infusions. CONCLUSION The combination of dark rhubarb roots or petioles and berries of black chokeberry, blackcurrant or some other anthocyanin-rich berries would have potential as both antibacterial and antioxidative additives in food. (c) 2018 Society of Chemical Industry

Brewers' spent grain (BSG) is the major by-product of the brewing industry which remain largely unutilized despite its nutritional quality. In this study, the effects of fermentation on BSG antioxidant potential were analyzed. A biotechnological protocol including the use of xylanase followed by fermentation withLactiplantibacillus plantarum (Lactobacillus plantarum)PU1, PRO17, and H46 was used. Bioprocessed BSG exhibited enhanced antioxidant potential, characterized by high radical scavenging activity, long-term inhibition of linoleic acid oxidation and protective effect toward oxidative stress on human keratinocytes NCTC 2544. Immunolabelling and confocal laser microscopy showed that xylanase caused an extensive cell wall arabinoxylan disruption, contributing to the release of bound phenols molecules, thus available to further conversion through lactic acid bacteria metabolism. To clarify the role of fermentation on the antioxidant BSG potential, phenols were selectively extracted and characterized through HPLC-MS techniques. Novel antioxidant peptides were purified and identified in the most active bioprocessed BSG.

Thymus capitatus and Thymus broussonnetii are two Moroccan endemic medicinal plants used traditionally by the local population. The present study aims to investigate their essential oil chemical composition, antioxidant and antibacterial activities. The chemical composition of the essential oils was determined using the GC-MS analysis, the antioxidant activity assessed using DPPH and FRAP methods while the antimicrobial activity was evaluated against nine bacteria species tested (Enterococcus faecalis, Serratia fonticola, Acinetobacter baumannii, Klebsiella oxytoca, sensitive Klebsiella pneumoniae, sensitive Escherichia coli, resistant Escherichia coli, resistant Staphylococcus aureus and Enterobacter aerogenes). The major identified compounds of T. capitatus essential oil where carvacrol (75%) and p-cymene (10.58%) while carvacrol (60.79%), thymol (12.9%), p-cymene (6.21%) and gamma-terpinene (4.47%) are the main compounds in T. broussonnetii essential oil. The bioactivity of the essential oils of the two species of thyme was explained by their richness in oxygenated monoterpenes known for their great effectiveness with an IC50 of 3.48 +/- 0.05 and 4.88 +/- 0.04 mu L/mL and EC50 of 0.12 +/- 0.01 and 0.20 +/- 0.02 mu L/mL in the DPPH and FRAP assays, respectively, with an important antibacterial activity. These results encourage the use of these plants as a source of natural antioxidants, and antibacterial additives, to protect food from oxidative damage and to eliminate bacteria that are responsible for nosocomial infections.

The antioxidant and antibacterial properties of four essential oils (oregano essential oil (OEO), tea tree essential oil (TTEO), wild orange essential oil (WOEO), and clove leaf essential oil (CLEO)) were determined. The in-vitro experiment indicated that CLEO had the highest total phenolic content and DPPH scavenging activity, and OEO displayed the highest antibacterial effect, so they were applied to maintain the quality of shrimp for further study. In-situ study, the total viable counts of shrimp were inhibited from 9.05 log CFU/g to 8.18 and 8.34 log CFU/g by 2% of OEO and CLEO treated alone on 10 d. The melanosis ratio was also retarded from 38.16% to 28.98% and 26.35% by the two essential oils. The inhibitory effects of OEO and CLEO on the increase of PPO activity, weight loss, and TCA-soluble peptides, and the decreasing tendency of whiteness, the contents of myofibrillar and sarcoplasmic proteins were also founded. The samples treated with 1% OEO + 1% CLEO had better quality than those treated alone. Therefore, the combination of OEO and CLEO had a synergistic effect, which displayed the highest efficiency to prevent the melanosis, bacterial growth, and protein hydrolysis of shrimp.

Bacteria interact with a multitude of other organisms, many of which produce antimicrobials. Selection for resistance to these antimicrobials has the potential to result in resistance to clinical antibiotics when active compounds target the same bacterial pathways. The possibility of such cross-resistance between natural antimicrobials and antibiotics has to our knowledge received very little attention. The antimicrobial activity of extracts from seaweeds, known to be prolific producers of antimicrobials, is here tested against Staphylococcus aureus isolates with varied clinical antibiotic resistance profiles. An overall effect consistent with cross-resistance is demonstrated, with multidrug-resistant S. aureus strains being on average more resistant to seaweed extracts. This pattern could potentially indicate that evolution of resistance to antimicrobials in the natural environment could lead to resistance against clinical antibiotics. However, patterns of antimicrobial activity of individual seaweed extracts vary considerably and include collateral sensitivity, where increased resistance to a particular antibiotic is associated with decreased resistance to a particular seaweed extract. Our correlation-based methods allow the identification of antimicrobial extracts bearing most promise for downstream active compound identification and pharmacological testing.

Synthetic dyes are vastly used for colouring numerous materials, although the adverse effects on environment are well recognized. In addition to developing the existing dyeing technologies more efficient and cleaner, the valorisation of natural dyes can enhance the sustainable development of dyeing industry. Natural indigo, derived from Isatis tinctoria, is a bio-based alternative for indigo produced via chemical synthesis routes. Owing to the insoluble character of indigo pigment, the dye requires conversion into soluble leucoindigo form prior to dyeing, which is often accomplished by using harsh sodium dithionite vat technique. During the processing from plant to dye attached on a fabric, indigo is transferred from the soluble leucoindigo form to the oxidized insoluble indigo and once more back to leucoindigo. Additionally, the oxidation is difficult to control and with traditional vat technique maintaining the leucoindigo through the dyeing often requires adding more reducing agent chemicals. Maintaining the soluble form throughout the process would enable lower number of processing steps and reduce the use of harmful chemical agents. In the present study, the stabilization of leucoindigo on nanocellulose matrix carrier was investigated with spectroscopic and photophysical methods. According to the results, leucoindigo was successfully stabilized on nanocellulose suspension, most likely due to the limited rate of oxygen diffusion into the viscous medium. Visual observations revealed that the leuco-form was retained even longer with natural indigo than synthetic indigo. This enhanced stability was attributed to the presence of radical scavenging species in natural indigo since the synthetic indigo did not show notable antioxidant properties. Given the promising results the paste formulation was demonstrated to be applicable for creating patterns on cotton using a screen-printing technique. Since the leucoindigo was stabilized on nanocellulose carrier, the need for re-reduction prior to dyeing was avoided and the amount of harmful reducing chemicals was reduced. These findings also show that the characteristics of natural dyes that are often considered disadvantageous compared to synthetic dyestuff, i.e. presence of co-products in the mixture, can however, create more value to the dyed material through new functionalities.

AbstractEthnopharmacological relevance Terminalia laxiflora Engl. & Diels, (Sudanese Arabic name: Darout الدروت) and Terminalia brownii Fresen (Sudanese Arabic name: Alshaf ألشاف) (Combretaceae) are used in Sudanese traditional folk medicine and in other African countries for treatment of infectious diseases, TB and its symptoms, such as cough, bronchitis and chest pain. Aim of study Because of the frequent use of T. laxiflora and T. brownii in African traditional medicine and due to the absence of studies regarding their antimycobacterial potential there was a need to screen extracts of T. laxiflora and T. brownii for their growth inhibitory potential and to study the chemical composition and compounds in growth inhibitory extracts. Materials and methods The plant species were collected in Sudan (Blue Nile Forest, Ed Damazin Forestry areas) and selected according to their uses in traditional medicine for the treatment of bacterial infections, including TB. Eighty extracts and fractions of the stem bark, stem wood, roots, leaves and fruits of T. laxiflora and T. brownii and nine pure compounds present in the active extracts were screened against Mycobacterium smegmatis ATCC 14468 using agar diffusion and microplate dilution methods. Inhibition zones and MIC values were estimated and compared to rifampicin. HPLC-UV/DAD, GC/MS and UHPLC/Q-TOF MS were employed to identify the compounds in the growth inhibitory extracts. Results The roots of T. laxiflora and T. brownii gave the best antimycobacterial effects (IZ 22–27 mm) against Mycobacterium smegmatis. The lowest MIC of 625 µg/ml was observed for an acetone extract of the root of T. laxiflora followed by methanol and ethyl acetate extracts, both giving MIC values of 1250 µg/ml. Sephadex LH-20 column chromatography purification of T. brownii roots resulted in low MIC values of 62.5 µg/ml and 125 µg/ml for acetone and ethanol fractions, respectively, compared to 5000 µg/ml for the crude methanol extract. Methyl (S)-flavogallonate is suggested to be the main active compound in the Sephadex LH- 20 acetone fraction, while ellagic acid xyloside and methyl ellagic acid xyloside are suggested to give good antimycobacterial activity in the Sephadex LH-20 ethanol fraction. RP-18 TLC purifications of an ethyl acetate extract of T. laxiflora roots resulted in the enrichment of punicalagin in one of the fractions (Fr5). This fraction gave a five times smaller MIC (500 µg/ml) than the crude ethyl acetate extract (2500 µg/ml) and this improved activity is suggested to be mostly due to punicalagin. 1,18-octadec-9-ene-dioate, stigmast-4-en-3-one, 5α-stigmastan-3,6-dione, triacontanol, sitostenone and β-sitosterol were found in antimycobacterial hexane extracts of the stem bark of both studied species. Of these compounds, 1,18-octadec-9-ene-dioate, stigmast-4-en-3-one, 5α-stigmastan-3,6-dione, triacontanol, sitostenone have not been previously identified in T. brownii and T. laxiflora. Moreover, both plant species contained friedelin, betulinic acid, β-amyrine and two unknown oleanane-type triterpenoids. Of the listed compounds, friedelin, triacontanol and sitostenone gave a MIC of 250 µg/ml against M. smegmatis, whereas stigmasterol and β-sitosterol gave MIC values of 500 µg/ml. Conclusions Our results show that T. laxiflora and T. brownii contain antimycobacterial compounds of diverse polarities and support the traditional uses of various parts of T. laxiflora and T.brownii as decoctions for treatment of tuberculosis. Further investigations are warranted to explore additional (new) antimycobacterial compounds in the active extracts of T. laxiflora and T. brownii.