67 research outputs found

    Chemical, molecular pharmacology and neuroprotective properties of the essential oil derived from Aloysia citrodora Palau

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    Essential oils derived from dried and fresh leaves of Aloysia citrodora were obtained by hydrodistillation, and were investigated for a range of pharmacological properties: receptor binding, in vitro acetylcholinesterase (AChE) inhibitory, antioxidant activities, and neuroprotection properties relevant to neurodegenerative diseases. Fresh leaf A. citrodora essential oil inhibited [3H] nicotine binding to well washed rat forebrain membranes, with mean apparent IC50 of 0.0018 mg/ml. No significant binding activity was observed for A. citrodora essential oil derived from fresh or dried leaves, for GABAAR and NMDARs. A. citrodora essential oil, both dried and fresh, exhibited radical scavenging activity (up to 100%, IC50 < 0.0001 mg/ml) and iron (II) chelating properties (approx. IC50 = 0.05 mg/ml), and showed neuroprotective characteristics against the toxic effects of H2O2 (100%, 0.001 mg/ml) and ÎČ-amyloid (approx. 50%, 0.01 mg/ml) in CAD neuronal cell culture. Both EOs from dried and fresh leaves also displayed effective AChE inhibitory activity, with the dried leaves oil displaying more clear AChE inhibitory activity than fresh oil, which could be related to the higher respective levels of caryophyllene oxide. Recombinant human anticholinesterase enzyme was used for structure based in silico screening of A. citrodora essential oil constituents for AChE Inhibitors, and the top scoring hits with highest pharmacophore fit values showed common interactions with residues at the active site of that of donepezil. The top seven hits in order of fit score, were ÎČ-curcumene, curcumene bisabolene, trans-calamenene, caryophyllene oxide, ÎČ-sesquiphellandrene and geranyl acetate. This indicates that plants may yield novel effective and safe AChE inhibitors, other than alkaloids. To begin to identify the chemicals underpinning the pharmacological properties of A. citrodora, GC/MS analysis of the chemical composition of the essential oil from leaves of A. citrodora identified eighty three major chemicals, including the presence of terpenoids, monoterpenes and sesquiterpenes, and 6-methyl-5-hepten-2-one, the main constituents being limonene, caryophyllene oxide, curcumene, spathulenol, 1,8-cineole constituting 47% of the total oil. Finally, a simple, inexpensive solid phase extraction method was developed for fractionation of essential oils. Collectively, this thesis provides a better understanding of the pharmacology of the Aloysia essential oil and its constituents relating to its potential use in the treatment neurodegenerative disease

    The lure of postwar London:networks of people, print and organisations

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    'Vernacular Voices: Black British Poetry'

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    ABSTRACT Black British poetry is the province of experimenting with voice and recording rhythms beyond the iambic pentameter. Not only in performance poetry and through the spoken word, but also on the page, black British poetry constitutes and preserves a sound archive of distinct linguistic varieties. In Slave Song (1984) and Coolie Odyssey (1988), David Dabydeen employs a form of Guyanese Creole in order to linguistically render and thus commemorate the experience of slaves and indentured labourers, respectively, with the earlier collection providing annotated translations into Standard English. James Berry, Louise Bennett, and Valerie Bloom adapt Jamaican Patois to celebrate Jamaican folk culture and at times to represent and record experiences and linguistic interactions in the postcolonial metropolis. Grace Nichols and John Agard use modified forms of Guyanese Creole, with Nichols frequently constructing gendered voices whilst Agard often celebrates linguistic playfulness. The borders between linguistic varieties are by no means absolute or static, as the emergence and marked growth of ‘London Jamaican’ (Mark Sebba) indicates. Asian British writer Daljit Nagra takes liberties with English for different reasons. Rather than having recourse to established Creole languages, and blending them with Standard English, his heteroglot poems frequently emulate ‘Punglish’, the English of migrants whose first language is Punjabi. Whilst it is the language prestige of London Jamaican that has been significantly enhanced since the 1990s, a fact not only confirmed by linguistic research but also by its transethnic uses both in the streets and on the page, Nagra’s substantial success and the mainstream attention he receives also indicate the clout of vernacular voices in poetry. They have the potential to connect with oral traditions and cultural memories, to record linguistic varieties, and to endow ‘street cred’ to authors and texts. In this chapter, these double-voiced poetic languages are also read as signs of resistance against residual monologic ideologies of Englishness. © Book proposal (02/2016): The Cambridge History of Black and Asian British Writing p. 27 of 4
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