Begleiter der Menschen = Ruderalpflanzen und andere
Vergleich: Siehe: Gemeinschaftsgruppen + Schattenbäume + Anhängsel (Margret Madejsky)
[Jonathan Reuben Rai Invernizzi]
2.1 ETHNOBOTANY
2.1.1 Definition
The term 'Ethnobotany' was coined in 1895 by the American botanist John
W. Harshberger to describe the studies of plants used by "primitive and
aboriginal people.". In a broader sense, it is
a combination of the study of people ('ethno'), and the study of plants
('botany'). (Balick and Cox, 1996:3.)
2.1.2 Importance
Ethnobotany is important for a multitude of reasons. The link between
people and plants in primitive societies is usually more clear and direct than
in more industrialised ones. This is thought
to be mostly because the mechanisms of production and marketing are so
complex in developed society, that the botanical origins of a processed product
are rarely known or understood by most individuals. In indigenous cultures
however, people often have a greater degree of interaction with the plants they
use, and consequently, possess knowledge about the properties of plants which
western society has largely lost (Balick and Cox, 1996:6-7).
The WHO. estimates that 80% of the people living in developing countries
almost exclusively use traditional medicine as their primary form of medical
care, with medicinal plants forming the principal constituent of these
traditional therapeutics (Eloff, 1997: 1). More primitive societies have
through necessity maintained and passed on knowledge concerning plant medicine
and
cultivation (Balick and Cox, 1996:6-7). Most often, this knowledge is
verbal and incorporated in local legend and folklore (Naranjo, 1995: 363).
Although it is often possible to scientifically validate certain
medicinal properties or traditional uses of plants by western methods, science
cannot explain how it is that certain groups of people around the world look to
these plants as sources of medicine in the first place (Wood, 1997:3).
Many modern western drugs also owe their development to the refinement
of natural plant products. In 1984, one quarter of American prescription drugs
were modelled 011 natural products.
Of this, 74% of pharmacologically active plant derived components were
discovered by following up on the ethnomedical use of the plant. Despite this,
it has been estimated that to date, only
around 15% of all angiosperms have been investigated chemically. S.
Africa contains almost 10% of the worlds plant diversity, however very little
chemical work has been done on medicinal
plants in this region. (Eloff, 1997: 1-2.) The South African species
remain an untapped reservoir of potentially important biologically-active
compounds (Fennel and van Staden, 2001 :23).
2.1.3 African ethnobotany
The ancient African healers have an extensive materia medica comprising
various herbs, animal parts, minerals and clays. In traditional African
medicine many food plants have medical usage, in contrast to orthodox western
medicine where most drugs are viewed as 'poisons' which when administered in
small doses, have the ability to heal. Apart from incorporating therapeutic
plants into the daily diet, African medicine also contains many powerful drugs,
as well as many African varieties of better-known western herbal-based drugs.
Preliminary studies of the in vitro antibacterial effectiveness of some
indigenous Southern African plants have been completed by people such as Rabe
and van Staden (1997), Khan and Nkunya (1991), Lin el ai., (1999) and McGaw,
Jager and van Staden (2000). However when compared to the extent of research of
the indigenous herbs of countries such as America and Australia, there has been
generally little attempt to evaluate African medicinal plants in general for
biological activity and medicinal usefulness (Khan and Nkunya, 1991:48).
Homeopathic drug proving of Okoubaka aubrevillei
2.2 ETHNOBOTANICAL RESEARCH METHODOLOGY
2.2.1 Screening methods for natural products with anti-microbial
properties
The three principal methods employed to evaluate the anti-microbial
properties of natural products are diffusion assays, dilution tests and
bioautography tests.
Within these methods, standardisation of technique has been difficult,
as many factors have been found to influence results. These factors include
culture medium composition, micro-organisms tested, extractive method, pH, and
solubility of the sample in the culture medium. (Rios, Recio and Villar,
1988:127.)
2.2.1.1 Diffusion assays
Diffusion methods of screening for anti-microbial properties of natural
products classically employ either disc, hole or cylinder methods as reservoirs
for the sample substance (Rios, Recio and Villar, 1988: 128). This method is
based on the principal that a reservoir containing an aqueous extract is
brought into contact with an inoculated medium. The solute will diffuse through
the interface into the agar gel until equilibrium is attained. After incubation
the diameter of growth-free area around the reservoir can be measured and taken
as the anti-microbial ability of that product.
(Hewitt and Vincent, 1989:38.)
Diffusion methods are well suited for the preliminary screening of pure
substances, such as alkaloids, terpenaids and flavanoids. These methods
however, cannot be used for samples that are difficult to diffuse in the media,
as there is no direct correlation between diffusion power and anti-microbial
activity. Therefore, when utilising agar plates (which are water-based) as a
culture medium, this method is not acceptable for testing samples that are not
highly soluble in water, regardless of whether the substance is originally
applied in a non-polar solvent or not. Diffusion assays are therefore not
suitable for testing the properties of essential oils or other non-polar
substances. (Rios, Recio and Villar, 1988: 127.)
Dry discs, as opposed to wet discs which contain a liquid sample, are
used to test for anti-microbial properties of ethanol extracts (Rios, Recio and
Villar, 1988: 131), and have the advantage of nullifying the unknown effect
that the rate of evaporation of the sample off the wet disc has on the results
of a disc assay, as noted in the experiments by Reid (2002).
Comparisons of the zones of inhibition of natural products with those of
synthetic antibiotics in disc-assay studies are only useful for establishing
the sensitivity of test organisms. Comparisons of the anti-microbial potency of
natural test substances and synthetic antibiotics cannot be made from these
measurements. (Rios, Recio and Villar, 1988: 142.) This is largely due to the
fact that many other factors such as diffusion ability can influence the size
of the zones of inhibition, resulting in misleading conclusions when comparing
the 2 different types of substances (Hewitt and Vincent, 1989:40).
The optimum effectiveness of the disc diffusion method has been found to
be obtained using Mueller-Hinton agar and standard micro-organisms (American
Type Culture Collection or similar) (Rios, Recio and Villar, 1988: 142).
[Margret Madejsky]
Ruderalpflanzen zeigen gegen Trittschäden auch gegen Umweltgifte beachtliche Resistenz. Sie vertragen Abgase, Reifenabrieb, metallverseuchte Böden und sauren Regen erstaunlich gut.
In dieser Anpassungsfähigkeit ist auch ihre gemeinsame Signatur verborgen. Damit beweisen sie, dass sie Widerstandskräfte gegen Umweltproblemstoffe in sich aufgebaut haben, die
möglicherweise auch dem Menschen nützlich sind. Die Pflanzen am Wegesrand sind daher als potentielle Heilpflanzen gegen sog. "Zivilisationskrankheiten" anzusehen; bspw. Allergien,
Asthma, Atemwegsreizung durch Benzol oder Ozon, Fettsucht, Infektanfälligkeit und Virusleiden, Hautleiden wie Neurodermitis und Schwermetallbelastung.
Im Grunde genommen sprechen diese Gewächse eine eindeutige Sprache. Betrachtet man einmal die Wegwarte (Cichorium intybus) -
Blat-o. = Kakerlake
Chel.
Ephestia kuehniella = Mehlmotte Arthropoda.
Felix. = cat domesticated itself for its
own survival
Laps. = Gemeinen Rainkohl
Mus muculus. = Maus
Musc-d. = Hausfliege
Onis. = Kellerassel
Panaeolus mushrooms [= Düngerlinge/= Tinterlinge/= Coprinaceae)]/an grasbewachsenen Standorten mit Dungablagerungen (auf Weideflächen mit Viehzucht)/Kulturfolger Fungi.x
Pariet. = Aufrechtes Glaskraut/wächst an/in Mauern/sucht Menschennähe
Passer.x
domesticus = Spatz
Plan-m. = Breitwegerich
Procyon. = Waschbär
Sanguis-s. = Rattenblut
Thlas. w = Hirtentäschlein/= Sheperd’s purse/Sprossteile/= Blutwurz/= Herzel/= Bauernsenf
Tineola bisselliella = Kleidermotte Arthropoda.
Tyto-alba. = Schleiereule
Wolf. ist geschaffen. als erste Begleiter des Menschen.
Urt.
Feldhasen./Feldmaus/Kohlweißling./Feldhamster/Rebhuhn/Wachtel/Feldlerche/Kiebitz/Rauch-/Mehlschwalbe/Gartenrotschwanz
Städtischen Kulturfolger: fels-/höhlenbewohnende Arten, für die die Gebäude der Menschen „Kunstfelsen“ darstellen: Stadttaube./Mauersegler/Dohle/Turmfalke./Hausrotschwanz/Winkelspinnen./Große Zitterspinne, Heimchen/Silberfischchen./Wanderratte./Eichhörnchen/Amsel