Lectures and Presentations
Articles in Publication
Final research and essay for MLS degree, Kent State University, August 2006: "Developing Guidelines on Henna:A Geographical Approach"
PhD dissertation: "The Geographies of the Black Henna Meme Organism and the Epidemic of Para-phenylenediamine Sensitization: A Qualitative History."
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This qualitative history investigates the problem of the global epidemic of para-phenylenediamine sensitization through the epidemiology of the black henna meme organism. ‘Black henna’ contains para-phenylenediamine oxidative dye, a highly sensitizing chemical which produces delayed hypersensitivity reactions on the skin. ‘Black henna’ body art evolved from traditional henna body art when artists began to add para-phenylenediamine to traditional henna body art because the chemical dye produced a faster, more efficient, darker stain. This chemical addition caused blistering, scarring in the area of the pattern, with a reaction appearing five to twenty days after application in about 15% to 50% of the subjects.
A maximization test of 10% para-phenylenediamine paste to skin causes sensitization in 100% of subjects in five or fewer applications. All tested 'black henna' pastes have higher concentrations of para-phenylenediamine, from 12% to 80%, and all 'black henna' temporary tattoo applications are larger than a patch test.
The connection between the body art and onset of the reaction was not well understood by patrons, and often not seen by the artists. The latent severe chemical sensitivities caused by these applications often remained invisible for years. The ‘black henna’ temporary tattoo became a popular souvenir of exotic destinations and local celebratory cosmetic, as well as a profitable informal economic venture for the artist; the understanding of the risks did not proliferate along with the ‘black henna’ meme.
The ‘black henna’ meme replicated from local practice into global cultural geographies through pop culture, tourism, and the Internet. Online and print media commentary about ‘black henna’ began around 1997, at which point the replication and evolution of the black henna meme organism became visible and recoverable, so the epidemiology of the ‘black henna’ meme can be recovered to trace the epidemiology of para-phenylenediamine sensitization.
This work analyzes the history, geography and cultural phenomenon of black henna meme organisms in the tourist industry through memetics and discourse analysis of online commentary on ‘black henna’ and the para-phenylenediamine sensitization epidemic produced by ‘black henna’ between 1997 to 2014. This work will also estimate the date of onset and size of the sensitization epidemic, and propose a solution of management through competing meme organisms.
Co-author: "Lawsonia inermis L. (henna): Ethnobotanical, phytochemical and pharmacological aspects," Ruchi Badoni Semwala, Deepak Kumar Semwala, Sandra Combrinck, Catherine Cartwright-Jones, Alvaro Viljoen. Journal of Ethnopharmacology, June 2014
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Abstract and Ethnopharmacological relevance:
The use of Lawsonia inermis L. (henna) for medicinal and cosmetic purposes is inextricably linked to ancient and modern cultures of North Africa and Asia. Literature and artwork indicates that Lawsonia inermis played an important holistic role in the daily lives of some ancient cultures, providing psychological and medicinal benefits, as well as being used for personal adornment. Although henna was historically applied to the hands and feet to protect against fungal pathogens and to hair to combat lice and dandruff, other traditional uses include the treatment of liver and digestive disorders, reduction of tissue loss in leprosy, diabetic foot disorders and ulcers.
Phytochemistry: Almost 70 phenolic compounds have been isolated from various parts of the plant. Naphthaquinones, which include the dying principle lawsone, have been linked to many of the pharmacological activities. The terpene, β-ionone is largely responsible for the pungent odour of the essential oil isolated from the flowers. In addition to other volatile terpenes, some non-volatile terpenoids, a single sterol, two alkaloids and two dioxin derivatives have also been isolated from the plant.
Bioactivity: Henna is a pharmacologically important plant with significant in vitro and in vivo biological activities. Although a myriad of pharmacological activities have been documented, the antioxidant and antimicrobial activities are the most thoroughly investigated. Some incidents of adverse reactions following application to the skin have been reported, but these are mainly confined to cases involving individuals with glucose-6-phosphate dehydrogenase deficiency and reactions to adulterants added to henna products.
Conclusions: Adulteration of henna is very common and may have resulted in unwarranted scientific findings. Phytochemical profiling studies of the plant, which are crucial for the establishment of proper quality control protocols, are lacking and hamper the development of medicinal products. Although many in vitro studies have been conducted to evaluate the pharmacological activities and many in vivo studies have focussed on the toxicity of extracts, more in vivo studies to validate pharmacological activities are needed. The roles of specific compounds and their synergies have not been comprehensively investigated.
CoAuthor: "Rapid analysis of the skin irritant p-phenylenediamine (PPD) in henna products using atmospheric solids analysis probe mass spectrometry,"
Weiyang Chena, Thobile. A.N. Nkosia, Sandra Combrincka, Alvaro. M. Viljoen, Catherine Cartwright-Jones
Journal of Pharmaceutical and Biomedical Analysis, Volume 128, 5 September 2016, Pages 119–125
Link to full text
Henna (Lawsonia inermis) is applied to stain keratin, present in hair, skin and fingernails, a red-orange or rust colour. Producers of temporary tattoos mix the aromatic amine compound, para-phenylenediamine (PPD) into natural henna to create ‘black henna’ that rapidly stains the skin black. However, PPD may cause severe delayed hypersensitivity reactions following skin contact. This study proposes a rapid direct-analysis method to detect and identify PPD using an atmospheric solids analysis probe (ASAP) coupled to a Q-ToF mass spectrometer (MS). Since laborious, multistep methods of analysis to determine PPD are undesirable, due to the instability of the compound in solution, a screening method involving no sample preparation steps was developed. Experiments were carried out to optimise the corona current, sample cone voltage, source temperature, and desolvation gas temperature to determine ideal ASAP-Q-ToF-MS analysing conditions. Eleven of the 109 henna samples, originating from various countries, tested positive for PPD when henna products were screened using ASAP-MS, without any form of sample preparation other than grinding. Ultra-performance liquid chromatography electrospray ionisation-mass spectrometry (UPLC-Q-ToF-MS) was subsequently used to confirm the results from ASAP and to determine the concentrations of PPD in henna products. The allergen was detected in the same eleven samples, with concentrations ranging from 0.05–4.21% (w/w). It can be concluded that the sensitivity of the ASAP-MS technique is sufficient (limit of detection = 0.025% w/w) to allow screening of henna samples for the presence of PPD. This relatively new technique can be applied to commercial products without extraction, sample treatment or chromatographic separation.
Author of articles: "cosmetics," "henna," "hamam" and "harem." The Oxford Encyclopedia of Islam and Women, Natana J. DeLong-Bas, ed.
Oxford University Press, 2013 ISBN-13: 9780199764464
Current Online Version: 2013 eISBN: 9780199764471
The Oxford Encyclopedia of Islam and Women provides clear, current, comprehensive information on the major topics of scholarly interest within the study of Islam and women. With more than 450 articles written by leading international experts and with a concentration on contemporary issues, it is a single source for accurate overview articles covering all aspects of this flourishing area of research. Organized around the central conceptual themes in research on Islam and women including Self and Body, Immigration and Minorities, Culture and Expression, Politics and Polity, and Community and Society, as well as Science, Medicine and Education among others, this work examines the scholarship on Islam and women that has expanded exponentially over the past twenty years, as well as cross-pollination between other fields and disciplines.
Author: "Henna Body Art in South Asia," Encyclopedia of Popular Culture in Asia and Oceania, Greenwood Press/ABC-CLIO
The ABC-CLIO/Greenwood Reference collection is filled with historical information of all kinds. It comprises authoritative resources on core topics such as business and war and also includes a breadth of biographies for today's most important people.