Kazhila C. Chinsembu

Model and experiences of initiating collaboration with traditional healers in validation of ethnomedicines for HIV/AIDS in Namibia.

Many people with Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS) in Namibia have access to antiretroviral drugs but some still use traditional medicines to treat opportunistic infections and offset side-effects from antiretroviral medication. Namibia has a rich biodiversity of indigenous plants that could contain novel anti-HIV agents. However, such medicinal plants have not been identified and properly documented. Various ethnomedicines used to treat HIV/AIDS opportunistic infections have not been scientifically validated for safety and efficacy. These limitations are mostly attributable to the lack of collaboration between biomedical scientists and traditional healers. This paper presents a five-step contextual model for initiating collaboration with Namibian traditional healers in order that candidate plants that may contain novel anti-HIV agents are identified, and traditional medicines used to treat HIV/AIDS opportunistic infections are subjected to scientific validation. The model includes key structures and processes used to initiate collaboration with traditional healers in Namibia; namely, the National Biosciences Forum, a steering committee with the University of Namibia (UNAM) as the focal point, a study tour to Zambia and South Africa where other collaborative frameworks were examined, commemorations of the African Traditional Medicine Day (ATMD), and consultations with stakeholders in north-eastern Namibia. Experiences from these structures and processes are discussed. All traditional healers in north-eastern Namibia were willing to collaborate with UNAM in order that their traditional medicines could be subjected to scientific validation. The current study provides a framework for future collaboration with traditional healers and the selection of candidate anti-HIV medicinal plants and ethnomedicines for scientific testing in Namibia.

Plants as antimalarial agents in Sub-Saharan Africa.

Although the burden of malaria is decreasing, parasite resistance to current antimalarial drugs and resistance to insecticides by vector mosquitoes threaten the prospects of malaria elimination in endemic areas. Corollary, there is a scientific departure to discover new antimalarial agents from nature. Because the two antimalarial drugs quinine and artemisinin were discovered through improved understanding of the indigenous knowledge of plants, bioprospecting Sub-Saharan Africas enormous plant biodiversity may be a source of new and better drugs to treat malaria. This review analyses the medicinal plants used to manage malaria in Sub-Saharan Africa. Chemical compounds with antiplasmodial activity are described. In the Sub-Saharan African countries cited in this review, hundreds of plants are used as antimalarial remedies. While the number of plant species is not exhaustive, plants used in more than one country probably indicate better antimalarial efficacy and safety. The antiplasmodial data suggest an opportunity for inventing new antimalarial drugs from Sub-Saharan-African flora.

Sexually Transmitted Infections in Adolescents

Adolescents are the age group at greatest risk for nearly all Sexually Transmitted Infections (STIs). Adolescents are often at a higher risk for acquiring STIs because they are unable to conceptualize actions and their consequences. STIs are more prevalent among adolescent women than men, thus two thirds of newly infected adolescents aged 15-19 years are female. For reasons of biology, gender and cultural norms, adolescent females are also more susceptible than males to STIs. Biologically, adolescent women face increased anatomical and physiological susceptibility to infection due to increased cervical ectopy. The clinical presentation of STIs in adolescents should be carefully examined because some conditions are asymptomatic while other unrelated disease symptoms can easily be mistaken for STIs. This review presents some emergent epidemiological data from developed and developing countries that demonstrate the heavy burden of STIs on adolescents. However, more adolescent-specific STI studies are needed worldwide.

Tuberculosis and nature's pharmacy of putative anti-tuberculosis agents.

Due to the growing problem of drug resistant Mycobacterium tuberculosis strains, coupled with the twinning of tuberculosis (TB) to human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), the burden of TB is now difficult to manage. Therefore, new antimycobacterial agents are being sought from natural sources. This review focuses on natural antimycobacterial agents from endophytes and medicinal plants of Africa, Europe, Asia, South America and Canada. In the countries mentioned in this review, numerous plant species display putative anti-TB activity. Several antimycobacterial chemical compounds have also been isolated, including: ellagitannin punicalagin, allicin, anthraquinone glycosides, iridoids, phenylpropanoids, beta-sitosterol, galanthimine, crinine, friedelin, gallic acid, ellagic acids, anthocyanidin, taraxerol, termilignan B, arjunic acid, glucopyranosides, 1-epicatechol, leucopelargonidol, hydroxybenzoic acids, benzophenanthridine alkaloids, neolignans, and decarine. These compounds may provide leads to novel and more efficacious drugs to lessen the global burden of TB and drug-resistant M. tuberculosis strains. If there is a long-term remedy for TB, it must lie in natures pharmacy of putative antimycobacterial agents.

Ethnobotanical Study of Plants Used in the Management of HIV/AIDS-Related Diseases in Livingstone, Southern Province, Zambia

Faced with critical shortages of staff, long queues, and stigma at public health facilities in Livingstone, Zambia, persons who suffer from HIV/AIDS-related diseases use medicinal plants to manage skin infections, diarrhoea, sexually transmitted infections, tuberculosis, cough, malaria, and oral infections. In all, 94 medicinal plant species were used to manage HIV/AIDS-related diseases. Most remedies are prepared from plants of various families such as Combretaceae, Euphorbiaceae, Fabaceae, and Lamiaceae. More than two-thirds of the plants (mostly leaves and roots) are utilized to treat two or more diseases related to HIV infection. Eighteen plants, namely, Achyranthes aspera L., Lannea discolor (Sond.) Engl., Hyphaene petersiana Klotzsch ex Mart., Asparagus racemosus Willd., Capparis tomentosa Lam., Cleome hirta Oliv., Garcinia livingstonei T. Anderson, Euclea divinorum Hiern, Bridelia cathartica G. Bertol., Acacia nilotica Delile, Piliostigma thonningii (Schumach.) Milne-Redh., Dichrostachys cinerea (L.) Wight and Arn., Abrus precatorius L., Hoslundia opposita Vahl., Clerodendrum capitatum (Willd.) Schumach., Ficus sycomorus L., Ximenia americana L., and Ziziphus mucronata Willd., were used to treat four or more disease conditions. About 31% of the plants in this study were administered as monotherapies. Multiuse medicinal plants may contain broad-spectrum antimicrobial agents. However, since widely used plants easily succumb to the threats of overharvesting, they need special protocols and guidelines for their genetic conservation. There is still need to confirm the antimicrobial efficacies, pharmacological parameters, cytotoxicity, and active chemical ingredients of the discovered plants.

Agroecological distribution of major stalk borers of maize in Zambia

Surveys were conducted in farmers’ fields in Zambia during the 1987/88, 1988/89 and 1989/90 cropping seasons, to evaluate the extent of attack on maize by stalk borers and their distribution in some selected maize growing areas in three agroecological regions. Infestation levels varied from season to season. Infestations were low (0.5–13%) in the Southern province: Gwembe Valley and Livingstone in region I and Chôma and Kalomo in region II. Infestation levels in other areas ranged from 21–75%. Three species of stalk borers, Busseola fusca, Chilo partellus and Sesamia calamistis were recorded. Their composition and proportion in the complex differed from place to place. C. partellus occurred at an altitude range of 350–1170m, B. fusca occurred at 1032 to >1300m above sea level. B. fusca was the most widely distributed and predominant.RésuméA fin d’évaluer l’importance d’attaque des foreurs de tige de maïs et leur distribution dans certains champs de maïs dans 3 zones agro-écologiques, des enquêtes ont été menées dans les champs des fermiers Zambiens pendant les saisons de culture 1987/88, 1988/89 et 1989/90. Les niveaux d’infestation étaient trés bas et variés d’une saison à l’autre (0,5–13%) dans la région I (la vallée de Gwembe et Livingstone) et dans la région II (Choma et Kalomo), province du sud. D’autres régions avaient un niveau d’infestation qui se situait entre 21–75%. Les 3 espéces de foreur de tige observées étaient Busseola fusca, Chilo partellus et Sesamia calamistis. Leur composition et leur nombre variés d’une place à l’autre. C. partellus était présent àune altitude se situant entre 350–1170m alors que B. fusca etait observe entre 1032m à plus de 1300m d’altitude au dessus du niveau de la mer. B. fusca était le plus répandu et le plus dominant.

Teeth are bones: Signature genes and molecules that underwrite odontogenesis

Understanding the molecular genetics of odontogenesis (tooth development) can unlock innovative avenues to genetically engineer teeth for therapy. In this review, emerging insights into the genetic and molecular bases of tooth development are presented. Four conserved signature genes express master molecules (fibroblast growth factors, bone morphogenetic proteins, wingless integrated ligands and sonic hedgehog protein) that underwrite odontogenesis. Five homeobox genes (Barx1, Dlx, Pax9, Msx and Pitx) and many secondary molecules (notably transcription factors) mediate signalling pathways that drive tooth initiation, morphogenesis and differentiation. The role of at least 57 genes and signalling molecules are presented in this work.