Ian Tietjen1, Barbara N Ngwenya2, Ghislain Fotso3, David E Williams4, Sundana Simonambango5, Bonaventure T Ngadjui6, Raymond J Andersen7, Mark A Brockman8, Zabrina L Brumme9, Kerstin Andrae-Marobela10. 1. Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada. Electronic address: itietjen@sfu.ca. 2. Okavango Research Institute (ORI), Maun, Botswana. Electronic address: bntomi@ori.ub.bw. 3. Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon. Electronic address: ghis152001@yahoo.fr. 4. Departments of Chemistry and Earth, Oceans & Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada. Electronic address: david.williams@ubc.ca. 5. Kwame (Legwame) Traditional Association, P.O. Box 3481, Mmadinare, Botswana. 6. Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon; Department of Pharmacognosy and Pharmaceutical Sciences, Faculty of Medicine and Biomedical Science, University of Yaoundé I, Yaoundé, Cameroon. Electronic address: ngadjuibt@yahoo.fr. 7. Departments of Chemistry and Earth, Oceans & Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada. Electronic address: raymond.anderson@ubc.ca. 8. Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada; Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada. Electronic address: mark_brockman@sfu.ca. 9. Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, Canada; British Columbia Centre for Excellence in HIV/AIDS, Vancouver, BC, Canada. Electronic address: zbrumme@sfu.ca. 10. Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon. Electronic address: marobelak@mopipi.ub.bw.
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE: Current HIV therapies do not act on latent cellular HIV reservoirs; hence they are not curative. While experimental latency reversal agents (LRAs) can promote HIV expression in these cells, thereby exposing them to immune recognition, existing LRAs exhibit limited clinical efficacy and high toxicity. We previously described a traditional 3-step medicinal plant regimen used for HIV/AIDS management in Northern Botswana that inhibits HIV replication in vitro. Here we describe use of one component of the regimen that additionally contains novel phorbol esters possessing HIV latency-reversal properties. AIM OF THE STUDY: We sought to document experiences of traditional medicine users, assess the ability of traditional medicine components to reverse HIV latency in vitro, and identify pure compounds that conferred these activities. MATERIALS AND METHODS: Experiences of two HIV-positive traditional medicine users (patients) were documented using qualitative interview techniques. Latency reversal activity was assessed using a cell-based model (J-Lat, clone 9.2). Crude plant extracts were fractionated by open column chromatography and reverse-phase HPLC. Compound structures were elucidated using NMR spectroscopy and mass spectrometry. RESULTS: Patients using the 3-step regimen reported improved health over several years despite no reported use of standard HIV therapies. Crude extracts from Croton megalobotrys Müll Arg. ("Mukungulu"), the third component of the 3-step regimen, induced HIV expression in J-lat cells to levels comparable to the known LRA prostratin. Co-incubation with known LRAs and pharmacological inhibitors indicated that the active agent(s) in C. megalobotrys were likely to be protein kinase C (PKC) activator(s). Consistent with these results, two novel phorbol esters (Namushen 1 and 2) were isolated as abundant components of C. megalobotrys and were sufficient to confer HIV latency reversal in vitro. CONCLUSION: We have identified novel LRAs of the phorbol ester class from a medicinal plant used in HIV/AIDS management. These data, combined with self-reported health effects and previously-described in vitro anti-HIV activities of this traditional 3-step regimen, support the utility of longitudinal observational studies of patients undergoing this regimen to quantify its effects on plasma viral loads and HIV reservoir size in vivo.
ETHNOPHARMACOLOGICAL RELEVANCE: Current HIV therapies do not act on latent cellular HIV reservoirs; hence they are not curative. While experimental latency reversal agents (LRAs) can promote HIV expression in these cells, thereby exposing them to immune recognition, existing LRAs exhibit limited clinical efficacy and high toxicity. We previously described a traditional 3-step medicinal plant regimen used for HIV/AIDS management in Northern Botswana that inhibits HIV replication in vitro. Here we describe use of one component of the regimen that additionally contains novel phorbol esters possessing HIV latency-reversal properties. AIM OF THE STUDY: We sought to document experiences of traditional medicine users, assess the ability of traditional medicine components to reverse HIV latency in vitro, and identify pure compounds that conferred these activities. MATERIALS AND METHODS: Experiences of two HIV-positive traditional medicine users (patients) were documented using qualitative interview techniques. Latency reversal activity was assessed using a cell-based model (J-Lat, clone 9.2). Crude plant extracts were fractionated by open column chromatography and reverse-phase HPLC. Compound structures were elucidated using NMR spectroscopy and mass spectrometry. RESULTS:Patients using the 3-step regimen reported improved health over several years despite no reported use of standard HIV therapies. Crude extracts from Croton megalobotrys Müll Arg. ("Mukungulu"), the third component of the 3-step regimen, induced HIV expression in J-lat cells to levels comparable to the known LRA prostratin. Co-incubation with known LRAs and pharmacological inhibitors indicated that the active agent(s) in C. megalobotrys were likely to be protein kinase C (PKC) activator(s). Consistent with these results, two novel phorbol esters (Namushen 1 and 2) were isolated as abundant components of C. megalobotrys and were sufficient to confer HIV latency reversal in vitro. CONCLUSION: We have identified novel LRAs of the phorbol ester class from a medicinal plant used in HIV/AIDS management. These data, combined with self-reported health effects and previously-described in vitro anti-HIV activities of this traditional 3-step regimen, support the utility of longitudinal observational studies of patients undergoing this regimen to quantify its effects on plasma viral loads and HIV reservoir size in vivo.
Authors: Khumoekae Richard; David E Williams; E Dilip de Silva; Mark A Brockman; Zabrina L Brumme; Raymond J Andersen; Ian Tietjen Journal: Viruses Date: 2018-06-27 Impact factor: 5.048