Comparison of the antibacterial activity of essential oils and extracts of medicinal and culinary herbs to investigate potential new treatments for irritable bowel syndrome

BACKGROUND:Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder, which may result from alteration of the gastrointestinal microbiota following gastrointestinal infection, or with intestinal dysbiosis or small intestinal bacterial overgrowth. This may be treated with antibiotics, but there is concern that widespread antibiotic use might lead to antibiotic resistance. Some herbal medicines have been shown to be beneficial, but their mechanism(s) of action remain incompletely understood. To try to understand whether antibacterial properties might be involved in the efficacy of these herbal medicines, and to investigate potential new treatments for IBS, we have conducted a preliminary study in vitro to compare the antibacterial activity of the essential oils of culinary and medicinal herbs against the bacterium, Esherichia coli.METHODS:Essential oils were tested for their ability to inhibit E. coli growth in disc diffusion assays and in liquid culture, and to kill E. coli in a zone of clearance assay. Extracts of coriander, lemon balm and spearmint leaves were tested for their antibacterial activity in the disc diffusion assay. Disc diffusion and zone of clearance assays were analysed by two-tailed t tests whereas ANOVA was performed for the turbidometric assays.RESULTS:Most of the oils exhibited antibacterial activity in all three assays, however peppermint, lemon balm and coriander seed oils were most potent, with peppermint and coriander seed oils being more potent than the antibiotic rifaximin in the disc diffusion assay. The compounds present in these oils were identified by gas chromatography mass spectrometry. Finally, extracts were made of spearmint, lemon balm and coriander leaves with various solvents and these were tested for their antibacterial activity against E. coli in the disc diffusion assay. In each case, extracts made with ethanol and methanol exhibited potent antibacterial activity.CONCLUSIONS:Many of the essential oils had antibacterial activity in the three assays, suggesting that they would be good candidates for testing in clinical trials. The observed antibacterial activity of ethanolic extracts of coriander, lemon balm and spearmint leaves suggests a mechanistic explanation for the efficacy of a mixture of coriander, lemon balm and mint extracts against IBS in a published clinical trial

Anti-virulence activities of selected culinary herbs against Pseudomonas aeruginosa

Dissertation (MSc (Microbiology))--University of Pretoria, 2021.Pseudomonas aeruginosa is a Gram-negative opportunistic bacterium that causes severe infections such as cystic fibrosis (CF), skin infections, and urinary tract infections (UTI), especially in immunocompromised patients. The pathogen relies on its virulence factors that get activated following a successful entry inside the host, resulting in diseases causing infections. Conventional techniques to battle this pathogen include the use of antibiotics. However, these antibiotics have proven to cause an increased resistance of the pathogen, which drives the need to come up with other means of fighting emerging multi-resistant pathogenic strains of P. aeruginosa. Alternatively, microbial pathogenicity can be attenuated by disturbing the communication system between bacteria, known as quorum sensing (QS). Therefore, to manage these bacterial infections, a novel strategy of anti-quorum sensing (AQS) could be used, as it exerts no selective pressure on bacterial cells, but only disrupts the bacterial communication. This study aimed to determine antivirulence properties of selected culinary herbs against Pseudomonas aeruginosa. The seven herbs, Apium graveolens, Coriandrum sativum, Rosmarinus officinalis, Salvia africana lutea, Salvia officinalis, Syzygium aromaticum and Thymus vulgaris were selected based on their reported health benefits they possess against diseases and ailments. The seven herbs were extracted with solvents of different polarities (water, hexane, ethyl acetate, methanol and dichloromethane), thereafter and determining minimum inhibitory concentrations (MIC) by microdilution assay against Pseudomonas aeruginosa. The Chromobacterium violaceum (biomonitor strain), which produces the purple violacein, was used for qualitative and quantitative AQS activities using the active extracts. The antivirulence assays (biofilm formation, elastase and pyocyanin productions, and twitching, swimming and swarming motility) of active extracts were evaluated against P. aeruginosa. Additionally, a chemical profiling of the active extracts was performed using gas chromatography coupled with mass spectrometry (GCMS) to identify possible compounds potentially responsible for the desired activities. Eleven extracts of Salvia officinalis (hexane and DCM), Rosmarinus officinalis (hexane and aqueous), Syzygium aromaticum (ethyl acetate, methanol, and DCM), Coriandrum sativum (ethyl acetate, methanol, hexane and DCM) displayed noteworthy MIC values of 1.00 mg/ml against P. aeruginosa. Moreover, the qualitative AQS activity revealed only two hexane extracts of Syzygium aromaticum and Coriandrum sativum potentially possess some AQS potential with inhibition zones of 9.00 mm and 16.00 mm at sub-inhibitory MIC (0.35 mg/ml), respectively. Quantitatively, C. sativum (hexane) extract showed higher percentage inhibition of 69% while and S. aromaticum (hexane) showed least AQS activity of 24% at 0.50 mg/ml. Only AQS active hexane extracts of S. aromaticum and C. sativum were subjected testing against virulence factors of P. aeruginosa. The two extracts of C. sativum and S. aromaticum (hexane) demonstrated percentage high biofilm inhibitions of 70.3% and 80.1% at 1.00 mg/ml, respectively. Furthermore, P. aeruginosa showed susceptibility with reduced twitching motility when treatment with 1.00 mg/ml of the extracts C. sativum hexane (36%) and S. aromaticum (43%). C. sativum hexane extract also reduced the swarming motility of Pseudomonas aeruginosa by 35% at 1.00 mg/ml. Whereas the hexane extract of S. aromaticum displayed 59% inhibition for elastase production. From the hexane extracts of S. aromaticum and C. sativum, 27 compounds were identified using GC-MS. Of the 27 compounds belonging to different classes of chemicals, some are known to possess a potential in inhibiting Pseudomonas sp at the quorum sensing level, such as Tetradecanoic acid, linoleic acid as well as phytol. This study validated and highlighted the herbs of S. aromaticum, and C. sativum possess antibacterial activities and antivirulence properties that could be used in attenuation of resistant P. aeruginosa, thereby used in management of its infectionsNRF Block grantMicrobiology and Plant PathologyMSc (Microbiology)Unrestricte

Scentinformatics: Mining of Structure-Odor Relationships and Scent-related Medical Effects for Mono-Molecular Odorants

In this dissertation, we address the unique challenge of establishing predictive relationshipsbetween chemical structure and scent properties of monomolecular odorants, in order to supportthe discovery of new odorants with targeted properties. This challenge is both difficult and excitingbecause unlike traditional medicinal agents tested in biological assays, scent properties arecharacterized by verbal descriptors rather than traditional quantitative metrics such as bindingconstants or dose-response curves. Thus, the stated challenge requires novel ways of quantifyingand harmonizing verbal scent descriptors of odorants to enable the use of cheminformatictechniques for scent research. In Chapter 1, we establish a natural language processing-basedtechnique for harmonizing subjective scent perception-based data. In Chapter 2, we build andvalidate Quantitative Structure-Odor Relationship models to predict standardized scent profilesfrom chemical structures. In Chapter 3, we develop a knowledge graph database that integratesbiomedical and scent-perceptual data linked to odorants, to enable the exploration of links betweenolfactory processes and biomedical phenomena. The processes detailed in the three chapters ofthis dissertation form a singular workflow designed to support odorant discovery research. Theprotocols developed in this thesis are made publicly available athttps://figshare.com/projects/AJT_Dissertation_UNC_CH_ESOP_CBMC_2022/137364.Doctor of Philosoph

Detection and quantification of paprika powder adulteration by near infrared (NIR) spectroscopy

Orientador: Douglas Fernandes BarbinDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de AlimentosResumo: A páprica é uma das especiarias mais consumidas no mundo, e devido aos seus atributos sensoriais desejáveis, ela apresenta um alto valor de mercado. Embora especiarias como o pó de páprica sejam usadas e consumidas apenas em pequenas quantidades, elas estão presentes em muitos alimentos processados. Em razão disso, ela se torna susceptível a adulteração por motivação econômica. Por esse motivo, muitos esforços têm sido feitos no desenvolvimento de técnicas analíticas para detecção dessas práticas fraudulentas. No entanto, muitas dessas técnicas tradicionais são destrutivas, utilizam reagentes químicos e seu uso é dispendioso e demorado. Por outro lado, técnicas de espectroscopia vibracional, aliadas a quimiometria, surgem como uma alternativa promissora na detecção de adulteração na indústria de ervas e especiarias. O uso dessas técnicas traz como vantagens a rapidez e a natureza não-destrutiva das análises. Dessa forma, a espectroscopia de infravermelho próximo (NIR) tem sido utilizada com êxito, na verificação da autenticidade e no controle de qualidade desses produtos. Diante disso, o presente trabalho teve como objetivo investigar as potencialidades da espectroscopia NIR, em conjunto com a análise multivariada, na detecção e quantificação de substâncias estranhas (fécula de batata, goma arábica e urucum), em páprica em pó. Na determinação dos níveis de adulteração, foi utilizada a regressão por mínimos quadrados parciais (PLSR). Melhores resultados da calibração PLSR foram obtidos com um número reduzido de variáveis, aplicando o método de seleção de variáveis a partir do gráfico dos coeficientes de regressão. Como resultado, para os modelos PLSR reduzidos construídos a partir dos dados espectrais de NIR, os coeficientes de determinação de predição (R2p) foram 0,960, 0,968 e 0,874 para fécula de batata, goma arábica e urucum, respectivamente e os erros quadráticos médios de predição (RMSEP) foram 1,86, 1,68 e 1,74, respectivamente. Finalmente, a análise discriminante de mínimos quadrados parciais (PLS-DA) foi o método utilizado para estabelecer um modelo de classificação para discriminar amostras de páprica adulteradas e não adulteradas e também identificar o tipo de adulteração. Assim, este método de classificação mostrou-se bastante eficiente, com especificidade maior que 90% e taxa de erro menor que 2%, para todos os modelos construídos. Os resultados obtidos neste estudo mostraram que a espectroscopia NIR, combinada com a quimiometria podem ser uteis para a rápida detecção e/ou quantificação da adulteração em páprica em póAbstract: Paprika is one of the most consumed spices in the world, and because of its desirable sensory attributes, it has a high market value. Although spices such as paprika powder are used and consumed only in small amounts, they are present in many processed foods. Because of this, it becomes susceptible to adulteration by economic motivation. For this reason, much effort has been expended in developing analytical techniques to detect such fraudulent practices. However, many of these traditional techniques are destructive, use chemical reagents and their use is expensive and time consuming. On the other hand, techniques of vibrational spectroscopy, combined with chemometrics, appear as a promising alternative in the detection of adulteration in the herb and spice industry. The use of these techniques brings as advantages the speed and the non-destructive nature of the analyses. Thus, near infrared spectroscopy (NIR) has been successfully used to verify the authenticity and quality control of these products. The objective of this study was to investigate the potential of NIR spectroscopy, in conjunction with the multivariate analysis, in the detection and quantification of foreign substances (potato starch, acacia gum and annatto) in powdered paprika. In the determination of adulteration levels, partial least squares regression (PLSR) was used. The best results of the PLSR calibration were obtained with a reduced number of variables, applying the method of selection of variables from the graph of the regression coefficients. As a result, for the reduced PLSR models built with NIR spectral data, the prediction determination coefficients (R2p) were 0.960, 0.968 and 0.874 for potato starch, acacia gum and annatto, respectively, and the mean squared errors of prediction (RMSEP) were 1.86, 1.68 and 1.74, respectively. Finally, the discriminant analysis of partial least squares (PLS-DA) was the method used to establish a classification model to discriminate adulterated and unadulterated paprika samples and also to identify the type of adulteration. Hence, this method of classification proved to be efficient, with specificity greater than 90% and error rate lower than 2%, for all models constructed. The results obtained in this study showed that NIR spectroscopy, combined with chemometrics may be useful for the rapid detection and / or quantification of paprika powder adulterationMestradoEngenharia de AlimentosMestre em Engenharia de AlimentosCAPE

Synergistic behaviour of Salvia and Notoginseng species in vascular diseases

As the mainstay and principal form of traditional Chinese medicine (TCM), Chinese herbal medicine (CHM) has been the subject of growing interest and popular use worldwide. However, its unique philosophy, diagnosis and prescription are completely different from Western Medicine (WM), which has brought great challenges for the quality standardisation, safety control, and efficacy evaluation confronting its development in a modernised scientific manner. This PhD project aims to address challenges that revolve around the efficacy research of CHM. Based on CHM theory, the key mechanism of the efficacy of CHM is the synergistic interactions among multiple herbal ingredients in a formula to reach an optimised therapeutic effect, multi-target mode of actions and reduced potential side effects. Several rigorous analytical methods such as combination index (CI), isobolographic analysis and systems biology are designed for the quantitative evaluations of synergistic effects in pharmaceutical combination therapy, and have also been utilised for the study of CHM. Among them, CI and isobologram models are applied for studying the interactions of a small number of active components or herbal extracts on the same target or receptor in which their chemical and pharmacological properties are well defined. A systems biology model may also be used to analyse multi-component, multi-target actions in combinational therapy. However, following a systematic review, it is apparent that the current literature on synergistic study of CHM is still at an early stage. Based on previous studies, we hypothesised that a platform to systematically analyse synergistic interactions of herbal compounds can be established by modern bioassays and scientific models (e.g., CI and isobologram approaches). Herb-pairs are the basic unit for the Chinese herbal formulae. Salvia Miltiorrhiza Radix et Rhizoma and Notoginseng Radix et Rhizome (known as Danshen [DS] and Sanqi [SQ] in TCM) has been one of the most frequently prescribed herb pairs in TCM clinics for cardiovascular disease management for over 30 years in Asian countries. However, very limited mechanistic studies on the combinational benefits on the complex pathological mechanisms of vascular diseases are available, despite the fact that the bioactivities for a single extract have been well studied. Therefore, the DS-SQ herb-pair was selected as a case study to address the issue of synergistic activities in CHM

High-throughput method for the extraction, isolation and identification of antifungal compounds from plants

This research aims to develop a high-throughput, standardised methodology for the extraction, isolation and identification of antifungal compounds from plants, using a bottom-up approach. The method development began with screening strains of non-pathogenic fungi Saccharomyces cerevisiae spp., and Komagataella phaffii, against solvent extractions from 22 different plants from various families in the classic 96-well microtitre Minimum Inhibitory Concentration (MIC) test. Plant extracts which displayed activity in the MIC test were then analysed with HPLC and HPLC-MS. One plant tested (Corema album) displayed significant activity against Candida albicans and Candida auris. This method identified three potential compounds, pinocembrin, 2,4-dihydroxychalcone and 7-hydroxyflavone. Pinocembrin gave an IC50 of 31.25 µg/ml against C. auris and should be considered for further pharmacological assessment

Elucidation of mechanisms by which culinary herbs and spices exert their inhibitory action on the growth of CRC cells in vitro

Colorectal cancer (CRC) is one of the most commonly diagnosed types of cancer in the developed countries and the incidence is rising in the developing regions. Chronic inflammation, which is propagated by overexpression of cyclooxygenase-2 (COX-2) and its major product prostaglandin E2 (PGE2), plays a key role in the development of CRC. Culinary herbs and spices (CHS) are rich in polyphenols, have a high anti-oxidant capacity and possess anti-inflammatory activity. It has been shown that CHS inhibit the growth of CRC cells, however, their anti-carcinogenic mechanisms are mainly unknown. Hence, the aim of this study was to identify the CHS that were most potent inhibiting the growth of CRC cells, and subsequently to elucidate their anti-carcinogenic mechanisms, in particular, focusing on COX-2, the Wnt/β-catenin signalling pathway, and proteins involved in apoptosis. Another goal was to investigate whether combining the CHS would result in synergistic effects on the above. This study demonstrated that CHS extracted in water/or ethanol and their combinations inhibited CRC cell growth. This study also revealed that the most potent CHS extracted in ethanol (turmeric (TE), bay leaf (BLE) and ginger (GE)) and combinations downregulated the expression of COX-2 and suppressed COX-2 activity by reducing PGE2 release; their effect was comparable to that of the selective COX-2 inhibitor Celecoxib (50 μM). These CHS also induced apoptosis in CRC cells by targeting several key proteins: p53, caspase-3, and PAPR. However, the CHS did not have an effect on Wnt signalling pathway, which partially could be due to insufficient treatment time. In conclusion, this study demonstrated that CHS and their combinations inhibited CRC cell growth, inhibited COX-2 expression and activity, and modulated several key molecules involved in the development of CRC. Based on these findings, CHS have the potential to be utilized for CRC chemoprevention and possibly be used as a complimentary treatment. However, in vivo studies are needed to establish the true potential of these foods

Advancing Social Equity and Promoting Black Self-determination: A Community Garden Opportunity Plan for Richmond, VA

Urban agriculture provides a variety of economic, environmental, and social benefits. Recognizing these benefits, the City of Richmond administers a community garden program known as “Richmond Grows Gardens.” Through this program, underutilized city properties are permitted for use as community gardens. However, an emerging concern is the potential for community gardens to perpetuate underlying structures of social and racial inequality through displacement and social exclusion. Considering these concerns, this plan investigates the implementation of community gardens in Richmond and establishes a methodology for ranking existing and available community garden sites based on the social and racial demographics of their surrounding communities. Furthermore, interviews with garden stewards reveal how decisions are made on the design, infrastructure, and process of community garden sites in Richmond, Va. Ultimately, this plan reinforces the idea that community gardens provide important opportunities to advance social equity and promote black self-determination. Community gardens are community assets that demonstrate collective power and, when implemented with intentionality, give communities the tools they need to define themselves. Accordingly, this plan establishes a credible vision for the future of community gardens in the city and provides pertinent recommendations and implementation strategies to ensure that community gardens advance social equity and black self-determination by anchoring community power

Development and Implementation of the Generations Eating Together Through Cooking (G.E.T.T. Cooking) Curriculum and Its Effects on an Inter-generational Population: A Pilot Study

The obesity epidemic continues to be a problem both in the US and worldwide. A number of factors have been attributed including: frequency of fast-food consumption, increased portion sizes, increased consumption of sugar-sweetened beverages, increased sedentary lifestyles, lack of nutrition knowledge, and lack of cooking skills. Nutrition intervention programs continue to be created providing innovative and creative ways of educating the public with pertinent knowledge and skills necessary for improving healthful behaviors; however, few programs focus on cooking skill development within a familial environment. The Generations Eating Together Through Cooking (G.E.T.T. Cooking) program was created by the lead researcher as a four-lesson, interactive cooking curriculum whose main objective was to increase cooking self-efficacy, nutritional knowledge, and family meal frequency while focusing on the intergenerational relationship of the participants. The curriculum was pilot tested from July to August 2015 with six grandparent-grandchild/ren pairings in Clemson, SC. A quasi-experimental, mixed-methods approach was used to assess changes in cooking self-efficacy, family meal frequency, and nutritional knowledge between pre- and post-intervention phases. Results demonstrated an increase in cooking self-efficacy in the children and grandparents. Nutritional knowledge also increased across all children participants. Grandparents demonstrated an increase in food safety and food behavior practices. Emerging themes throughout the intervention phase focused on cooking skill acquisition highlighting an increased comfort in knife handling, fruit and vegetable preparation, and raw meat handling. A two-month follow-up interview conducted with the parents, grandchildren, and grandparents provided evidence to the sustainability of the nutrition knowledge and cooking skills. The largest barrier to child participation in cooking activities was school. Enthusiasm for continued practice at home and participation in the program was expressed by all participants. Parents did not participate in the intervention yet expressed the positive changes in diet and attitudes toward food preparation activities noticed in the child participants. Future research will aim at implementing the curriculum with a larger, more economically and ethnically diverse population