Abstract
Ph.D. (Botany)
The most well-known tonic plants in South Africa have been used traditionally for the
treatment of a great variety of ailments but aspects of their ethnobotany and chemistry
remain poorly studied. Possible relationships between their ethnobotany and pharmacology
are mostly speculative. In this study, literature reviews of the ethnobotany of these plants
were combined with phytochemical screening studies and bitterness taste testing results in
order to establish constituent patterns which may contribute to a scientific rationale for the
claimed tonic (stimulating) properties of these plants.
The tonic concept and definitions of terms associated with it are often used incorrectly and
ambiguously. An analysis of literature on the traditional healing systems across the globe was
used to establish the historical and cultural aspects relevant to tonics. This analysis revealed
that sickness/illness is usually considered to be a result of imbalance in many cultures,
whether this imbalance is between the patient and the environment or due to a lack of
homeostasis in the body. In several healing cultures substances or mixtures of substances
are used to rectify these imbalances through proposed effects on several bodily systems
concurrently. According to some cultures, as in Eastern and Indian traditional medicine, tonic
plants are considered superior to other medicinal plants in that they impart health, strength
and a general sense of well-being, as well as being prophylactic. This definition of a tonic
plant is consequently broad, but excludes plants merely used as multipurpose medicines.
Where these tonics exhibit a specific mode of action, further classification is required, i.e. as
bitter, adaptogenic, alterative, adjuvant or stimulant tonics.
The South African traditional tonic plants studied were Agathosma species (Rutaceae), Aloe
species (Asphodelaceae), Arctopus species (Apiaceae), Artemisia afra (Asteraceae),
Balanites maughamii (Balanitacae), Dicoma species (Asteraceae), Harpagophytum
procumbens (Pedaliaceae), Hypoxis hemerocallidea (Hypoxidaceae), Muraltia heisteria
(Polygalaceae), Sutherlandia species (Fabaceae), Vernonia oligocephala (Asteraceae),
Warburgia salutaris (Canellaceae), Withania somnifera (Solanaceae) and Ziziphus
mucronata (Rhamnaceae). A detailed compendium of medicinal applications was compiled
following a thorough, in-depth scrutiny of the historical and medicinal ethnobotany of each of
these species. Such ethnobotanical data is important in understanding the cultural aspects of
healing in southern Africa, and provides valuable direction and focus with regards to the
phytochemical and pharmacological research of these plants.