Table Of ContentToxicological Survey of African Medicinal Plants
Toxicological Survey of
African Medicinal Plants
Edited by
Victor Kuete
Faculty of Science
University of Dschang, Cameroon
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Preface
Poisonous medicinal plants can affect the entire spectrum of organ systems in
humans, with some plants having several toxic principles that affect different sys-
tems. Africa has a rich and varied flora that includes a wide variety of plants with
the potential to cause poisoning of animals and humans. The last three decades
have experienced the boom of published scientific data on the pharmacological
activities of medicinal plants. Furthermore, evidence of the toxicological properties
is being intensively provided with considerable efforts by African scientists.
Although there is a large amount of information in the veterinary field, human poi-
soning appears to be less well documented especially when medicinal plants are
concerned. Until now, there is no global standard book highlighting the toxic
potential of African medicinal plants. In the previous standard book on African
Medicinal Plant published by Elsevier 2013, we documented the pharmacological
potencies of the medicinal plants of Africa, as well as their chemical constituents.
The interrelationship of pharmacology and toxicology is important as therapeutic
efficacy occurs at a lower dose, where overdosing can induce poisoning or severe
sideeffects.However,toxicplantsmaycontainactivemoleculesthatdisplayuseful
pharmacological effects. With the current emphasis on research and development
of phytomedicines throughout the continent, it is imperative to be aware of and
have some information on the harmful potential and toxic components of African
plants.Priortoanypharmacological screenings, westronglyencouragescientists to
search available literature for known toxic properties of plants of interest. In this
book, we produced andcompiled scientific data on alltoxicological as well as ben-
eficial aspects of African plants. In the first part of the book, from Chapters 1(cid:1)4,
we provide baseline information for a comprehensive approach of the topics dis-
cussed on African plants. Hence, we discussed at the continental level, the toxico-
logical societies (Chapter 1), the ethical issues (Chapter 2), the review of the
guidelines and methods (Chapter 3), as well as discordant results reported
(Chapter 4). In the second part, from Chapters 5(cid:1)18, we discussed the acute and
subacute(Chapter5)aswellasthesubchronicandchronic(Chapter 6)toxicities of
plantsusedforhumantherapyinthecontinent,andwefinallybroughtoutinforma-
tion about the toxic plants (Chapter 7), with emphasis of the effect at cellular level
(Chapter 8). We also reported the effect of African medicinal plant on human
genomeaswellastheirabilitytoleadtodeleteriouseffects ondevelopmentknown
asteratogenesis(Chapter9),theirabilitiestoleadtocancer,knownascarcinogene-
sis, and their toxic effects on the genetic material and the inheritance of these
effects, known as mutagenesis (Chapter 10). In the second part, we also discussed
the organ toxicity as well as protective effects of African medicinal plants,
xxii Preface
considered effects at the level of organ function such as the liver (Chapter 11),
kidney (Chapter 12), heart (Chapter 13), central nervous system (Chapter 14),
reproductive system (Chapter 15), skin and eyes (Chapter 16), spleen and lung
(Chapter 17). In Chapter 18, we attempted to highlight African medicinal plants
with good pharmacological potential and low side effects. In the third part of the
book, we included knowledge on the potential toxic and protective constituents of
African plant (Chapters 19(cid:1)21) in order to predict their possible side effects, even
if their toxicity profiles were not investigated. Finally, in the fourth part, we ana-
lyzed the physical (Chapter 22) and biochemical (Chapter 23) parameters involved
in therapy with African medicinal plants. To place African research globally and
forapossibleacademicuse,emphasiswasputonthegeneralknowledgeintoxicol-
ogy, principle of the methods used in the screenings as well as their limitation, and
tools for data interpretations. The topics of this book are of interest for scientists of
several fields including Pharmaceutical Science, Pharmacognosy, Complementary
and Alternative Medicine, Ethnomedicine, Pharmacology, Medical and Public
Health Sciences, Phytochemistry, and Biochemistry. The highlight of this book is
an exhaustive compilation of scientific data related to the toxicological and safety
survey of African plants by up to top scholars from several countries. Finally,
I would like to thank Molly McLaughlin, the Editorial Project Manager at Elsevier
(225 Wyman Street, Waltham, Massachusetts 02451), Vignesh Tamil, the technical
assistant, and Stalin Viswanathan, the production manager, for their help and
fruitfulcollaboration.
VictorKuete
List of Contributors
Adejuwon Adewale Adeneye Department of Pharmacology, Faculty of Basic
Medical Sciences, Lagos State University College of Medicine, Ikeja, Lagos,
Nigeria
Akanji Musbau Adewunmi Phytomedicine, Toxicology and Reproductive
Biochemistry Research Laboratory, Department of Biochemistry, University of
Ilorin,Ilorin,Nigeria
Roland E. Akhigbe Department of Physiology, Ladoke Akintola University of
Technology,Ogbomoso,Oyostate,Nigeria
Afolabi Clement Akinmoladun Phytomedicine, Drug Metabolism and Toxicology
Unit, Department of Biochemistry, School of Sciences, The Federal University of
Technology,Akure,Nigeria
Jules C.N. Assob Department of Biomedical Sciences, Faculty of Health Sciences,
UniversityofBuea,Cameroon
Doriane E. Djeussi Department of Biochemistry, Faculty of Science, University of
Dschang,Dschang,Cameroon
Jean P. Dzoyem Department of Biochemistry, Faculty of science, University of
Dschang, Cameroon; Phytomedicine Programme, Department of Paraclinical
Sciences,FacultyofVeterinaryScience,UniversityofPretoria,SouthAfrica
Martins Ekor Department of Pharmacology, School of Medical Sciences,
UniversityofCapeCoast,CapeCoast,Ghana
Wafaa El Sayed Abd El-Aal Professor of Pathology, National Research Center,
Cairo,Egypt
Esameldin E. Elgorashi Toxicology and Ethnoveterinary Medicine, ARC-
OnderstepoortVeterinaryResearchInstitute,Onderstepoort,SouthAfrica
Jacobus N. Eloff Phytomedicine Programme, Department of Paraclinical Sciences,
FacultyofVeterinaryScience,UniversityofPretoria,Onderstepoort,SouthAfrica
xxiv ListofContributors
Aime´ G. Fankam Department of Biochemistry, Faculty of Science, University of
Dschang,Dschang,Cameroon
Ebenezer Olatunde Farombi Drug Metabolism and Toxicology Unit,
Department of Biochemistry, College of Medicine, University of Ibadan, Ibadan,
Nigeria
Louis L. Gadaga Drug and Toxicology Information Service (DaTIS), School of
Pharmacy and Department of Clinical Pharmacology, College of Health Sciences,
UniversityofZimbabwe,Avondale,Harare,Zimbabwe
Ngueguim K. Glawdys Department of Biochemistry, Faculty of Science,
UniversityofDschang,Dschang,Cameroon
Rebecca HammDepartment ofPharmaceuticalBiology, Institute ofPharmacy and
Biochemistry,UniversityofMainz,Mainz,Germany
Alfred Ekpo Itor Department of Biochemistry, Faculty of Science, University of
Dschang,Dschang,Cameroon
Victor Kuete Department of Biochemistry, Faculty of Science, University of
Dschang,Cameroon
Namrita Lall Department of Plant Sciences, University of Pretoria, Pretoria, South
Africa
Faustin Pascal Tsague´ Manfo Department of Biochemistry and Molecular
Biology,FacultyofScience,UniversityofBuea,Cameroon
Armelle T. Mbaveng Department of Biochemistry, Faculty of Science, University
ofDschang,Dschang,Cameroon
Lyndy J. McGaw Phytomedicine Programme, Department of Paraclinical
Sciences, Faculty of Veterinary Science, University of Pretoria, Onderstepoort,
SouthAfrica
Edouard Akono Nantia Department of Biochemistry, Faculty of Science,
UniversityofBamenda,Cameroon
Neville Mvo Ngum Department of Biomedical Sciences, Faculty of Health
Sciences,UniversityofBuea,Cameroon
Jaure`s A.K. Noumedem Department of Biochemistry, Faculty of Science,
UniversityofDschang,Dschang,Cameroon
ListofContributors xxv
Dickson S. Nsagha Department of Biomedical Sciences, Faculty of Health
Sciences,UniversityofBuea,Cameroon
EmekaC.OkerekeDepartmentofPharmacologyandToxicology
TheophineChinwubaOkoyeDepartmentofPharmacologyandToxicology
Ajiboye Taofeek Olakunle Antioxidants, Free Radicals, Functional Foods and
Toxicology Research Laboratory, Department of Biological Sciences, Al-Hikmah
University,Ilorin,Nigeria
Mary Tolulope Olaleye Phytomedicine, Drug Metabolism and Toxicology Unit,
Department of Biochemistry, School of Sciences, The Federal University of
Technology,Akure,Nigeria
CollinsA.OnyetoDepartmentofPharmacologyandToxicology
Armel J. Seukep Department of Biochemistry, Faculty of Science, University of
Dschang,Dschang,Cameroon
Germain S. Ta¨ıwe Department of Zoology and Animal Physiology, University of
Buea,Cameroon
Dexter Tagwireyi Drug and Toxicology Information Service (DaTIS), School of
Pharmacy and Department of Clinical Pharmacology, College of Health Sciences,
UniversityofZimbabwe,Avondale,Harare,Zimbabwe
Jean-de-Dieu Tamokou Faculty of Science, Department of Biochemistry,
UniversityofDschang,Dschang,Cameroon
Simplice B. Tankeo Department of Biochemistry, Faculty of Science, University
ofDschang,Dschang,Cameroon
GeraldNgoTekeDepartment ofBiomedicalSciences,FacultyofHealthSciences,
UniversityofBamenda,Bambili,Cameroon
Francesco K. Touani Department of Biochemistry, Faculty of Science, University
ofDschang,Dschang,Cameroon
Yakubu Musa Toyin Phytomedicine, Toxicology and Reproductive Biochemistry
Research Laboratory, Department of Biochemistry, University of Ilorin, Ilorin,
Nigeria
Danielle Twilley Department of Plant Sciences, University of Pretoria, Pretoria,
SouthAfrica
xxvi ListofContributors
Phillip F. Uzor Department of Pharmaceutical and Medicinal Chemistry, Faculty
ofPharmaceuticalSciences,UniversityofNigeria,Nsukka,EnuguState,Nigeria
Igor K. Voukeng Department of Biochemistry, Faculty of Science, University of
Dschang,Dschang,Cameroon
Qiaoli Zhao Department of Pharmaceutical Biology, Institute of Pharmacy and
Biochemistry,UniversityofMainz,Mainz,Germany
1
Toxicological Societies in Africa:
Roles and Impact in Policy Making
and Living Conditions
Jules C.N. Assob1, Dickson S. Nsagha1,
Neville Mvo Ngum1 and Victor Kuete2
1DepartmentofBiomedicalSciences,FacultyofHealthSciences,University
ofBuea,Cameroon,2DepartmentofBiochemistry,FacultyofScience,
UniversityofDschang,Cameroon
1.1 Introduction
Africaand other developing countries are experiencing a risein both informal min-
ing especially artisanal gold mining and other fluctuating informal industrialactivi-
ties that are often situated within communities and surrounded by the mainstream
population. This, together with the increasing population migration and rapid
urbanization that encompasses a wide range of anthropogenic activities, contribute
to environmental degradation and pollution. The high prevalence of infectious dis-
eases such as lung diseases, tuberculosis, human immunodeficiency virus/acquired
immunodeficiency syndrome coupled with the malaria endemicity make the popu-
lations of Africa and other developing countries more susceptible to the toxic
effectsofpollutants[1].
Human exposure to persistent toxic substances (PTS) including both toxic
metals exposure and persistent organic pollutants (POPs) exposure can be from
either natural sources, current industrial activities, past industrial activities, or
anthropogenic activities. PTS have the ability to exert negative health effects that
are often subtle, long term, sometimes transgenerational, and difficult to measure,
even in large epidemiological studies. Furthermore, the continuous consumption of
unsafefoodfollowingpesticideandchemicalexposureremainsamajorglobalpub-
lichealthchallenge,especiallyinAfrica,wherethereisheavyapplicationofavari-
etyofchemicalsyetsolittleavailabletoxicologicaldataonthechemicals[2].
Althoughnecessarymeasureshavebeentakenbydevelopedcountriestocurbboth
the exposure and the effects to toxic substances, developing countries in general and
Africancountriesinparticularstilllagbehind[2].Generally,thevariousgovernments
in Africa have enacted policies and institutions with regard to the use and control of
ToxicologicalSurveyofAfricanMedicinalPlants.DOI:http://dx.doi.org/10.1016/B978-0-12-800018-2.00001-7
©2014ElsevierInc.Allrightsreserved.
