CHAPTER ONE
Introduction
Natural product derived from plants has
remained central to traditional medicine and has helped serve as sources
of new drugs with good therapeutic effect and low toxicity.
Unfortunately, the sleeping giant of pharmaceutical industrystill has
several of thousands of plants species yet to be investigated for their
phytoconstituents and invariably, their biological potentials(Hambuger
and Hostetham, 1991). Therefore, the need for continuous search into the
phytochemicals or such plants cannot be undermined. Nauclea latifolia
is a shrub or small tree native to tropical Africa. The leaves are
glabrous, opposite, rounded-ovate, glossy green with tufts of hairs. The
fruits are usually fleshy, shallow-pitched, with numerous and brownish
with a pleasant taste but could be emetic if taken in excess (wu,1993).
Traditionally, the plant has been reported as an antimalarial,(Abbiw,
1990) antibacterial(wu etal,1999) and antiviral, (Moral,1994). Other potentials of the fruits include, as a laxative(Jiofact etal, 2010) and hypocholesterolemic(Omale et al, 2011).Phytochemicals such as alkaloids(Atta-ur-Rahman, 2003),saponins (Morah, 1994), tannins, oxalates, phytates(Nkafamiya et al., 2006) and phthalates(Fadipe, 2014) have been detected and isolated from various parts of the plant.
In view of the continuous search for more phytochemicals from the leaves of N.latifolia, this study was conducted to investigate the antioxidant potentials in the aqueous extract of the leaves and fruits of Nauclea latifolia as these could be the contributing factors to their health beneficial effects.
LITERATURE REVIEW
NAUCLEA LATIFOLIA
Nauclea latifolia is a
straggling evergreen, multistemmed shrub or small tree which is native
to tropical Africa and Asia. The fruits serve as a key source of food
for the baboons, livestock,reptives birds and man. It is called
“African quinine” in northern Nigeria. The Fulanis in Nigeria use the
leaf extract to regularly deworm animals (Adebowale, 1993). Parts of the
plant are commonly prescribed traditionally as a remedy for diabetes
mellitus. The plant is also used in the treatment of ailments like
malaria(Kokwaro, 1976), gastrointestinal tract disorders (Maduabunyi,
1995), sleeping sickness(Kerharo,1994), prolong menstral flow( Elujoba,
1995),hypertension(Akabue and Mittal, 1982) and as a chewing
stick(Asubiojo et al., 1982).
BOTANICAL DESCRIPTION
N. latifolia is a straggling
shrub or small spreading tree. It is a smalldeciduous soft-wooded tree
with corky bark. The tree was up to 7.6m highwith a large broad leaf of
about 15 – 20cm. N. latifolia belongs to thefamily of
Rubiaceae, the family that consists of 150 genic and 350species of
deciduous tree. It is easily identified by its compound broadleaves.
It bears an interesting flower, a large red ball with longprojecting stamens. The fruit is red, edible, but not appealing.
ORIGIN
It is a plant of the family, rubiaceae
native to savannah and fringe tropical forest of west Africa (Irvine,
1961). It is wide spread in the humid and tropical rain-forests or in
savannah woodlands of west and central Africa.
TAXONOMY
Kingdom: plantae
Phylum: Tracheophyta
Subphylum: Euphyllophyhna
Class: Angiospermae
Subclass: Dicotyledon
Order: Rubiales
Family: Rubiaceae
Genrs : Nauclea
Species: Latifolia
Common names
English: pin cushiontree
Igbo: Uburu inu
Yoruba: egbesi
Hausa: tabasiya
ECOLOGY
African peach is a deciduous shrub or
tree with an open canopy, usually branching from low down the hole. It
varies widely in height from around 10meters up to 30metres according to
soil and moisture conditions. The edible fruits is gathered from the
wild for local use. Much appreciated by the local populace, it is often
sold in local markets.
PROPERTIES OF N. LATIFOLIA
Rhynchophylline is an interesting alkaloid with many health benefits. It is also a major constituent in Kratom (Mitragyna speciosa), and is also found in N. latifolia. The presence of phychoactive substances are indicated in the aqueous extract of the root bark of N. latifolia.
Key constituents are indole-quinolizidine alkaloids and glycoalkaloids
and saponins. The major one include nauclefine and naucletine. A novel
indole alkaloid, nauclefolinine and five known triterpenic compounds,
rotundic acid, a-L-rhamnoquinovic acid, 3-0-b-D-
glucopyranosyl-bsitosterol, squalene and sitosterol-3-0.6’-
stearoyl-b-D-glucopyranoside have been isolated from the roots of N. latifolia (Deeni, 1991).
USES OF N. LATIFOLIA
N. latifolia plant is used as a tonic and fever medicine, chewing stick,toothaches, dental caries, septic mouth and diarrhoea (Lamidi et al.,1995). There are studies showing that root of N. latifolia has antibacterial activity against gram positive and gram negative bacteriaand antifungal activity (Iwu, 1993). The root of N. latifolia is mosteffective against Corynebacterium diphtheriae, Streptobacillus spp,Streptococcus spp, Neisseria spp, Pseudomonas aeruginosa, Salmonellaspp (Deeni, 1991). In Congo, the roots of N. latifolia are
used as aphrodisiac and analgesic. The roots are also used in the Congo
for sexual asthenia (loss ofstrength). In Guinea, the roots are used as
a tonic/stimulant/restorative.The stem bark is used as an aphrodisiac
in Nigeria. The wood known as‘njimo’ is used as a stimulant and tonic. A soft drink is prepared from thefruit (Deeni, 1991). N. latifolia is
also used in the treatment of ailments like malaria. (Kokwaro, 1976;
Akabue and Mittal, 1982; Boye, 1990), gastrointestinal tract disorders
(Maduabunyi, 1991), sleeping sickness (Kerharo, 1974), prolong menstrual
flow (Elujoba, 1995), hypertension (Akabue andMittal, 1982); jaundice,
diarrhoea and dysentery.
TRADITIONAL MEDICINE
Herbal
medicine is a practice that involves the use of natural plant substances
(botanicals) to treat and prevent illness. Herbal medicine is sometimes
called botanical medicine or phytotherapy. Herbal medicine is the use
of plant, their water or solvent extracts, essentials oils, gums,
resins, exudates or other form of advanced products made from plant
parts used therapeutically to provide proacture support of various
physiological systems; or in a more conventional medical sense to treat,
cure, prevent disease in animals or humans (Thompson et al.,
2009). It has medicinal use in Igbo land, the decoction of the leaves is
recommended for stomach upset, especially in children. The infusion of
the root is also used as a remedy for stomach upset in adults. The dose
is one tea cup twice daily (Pais and Dumitrasco, 2013). The fruits is
recommended for piles, dysentery, colic, pretic and menstrual disorders.
The root is chewed as chew-sticks. Other ethno uses of N.Lalifolia
include malaria, leprosy, piles, gonorrhoea, debility dyspepsia and
gastro enteritis (Nikolova, et al., 2013).
Traditional birth attendant in Nigeria have used the ethanolic extract of Narclea latifolia(stem
and root) bark in arresting preterm contradictions in pregnant women.
Thuterus is a hollow, thick-walled muscular organ located in the female
pelvis between the bladder and rectum. (Cortis-jofreptal, 2002). It lies
between the blader in front and the pelvic sigmoid colon and rectum
behind, and is completely within the pelvis so that its base is below
the level of superior pelvic apertune.
Natural products derived from
plants have remained central to traditional medicine and has helped
served as sources of new drugs with good therapeutic effect and low
toxicity. Unfortunately, the (Hamburger and Hostettman, 1991) sleeping
giant of pharmaceutical industry still has several of thousand of plants
species yet to be investigated for their phytoconstituents
andinvariably, their biological potentials. Parts of the plants are
commonly prescribed traditionally as a remedy for diabetes mellitus. The
plant is also used in the treatment of ailments like malaria, gastro
intestinal tract disorders (Maduabunyi, 1995), sleeping sickness (
Kerbaro, 1974), prolong menstrual flow (Elujoba, 1995), hypertension (
Akabre and Mittal, 1982) and as a chewing stick (Asubiojo et al.,1982).
ROLE OF TRADITIONAL MEDICINE: ITS BENEFITS AND CHALLENGES
Despite many achievements in human
healthcare in the twentiethcenturies, many of the world’s population in
developing countries lackregular access to affordable essential drugs.
For these people, modernmedicine is never likely to be a realistic
treatment option. In contrast,traditional medicine is widely available
and affordable, even in remoteareas. It is important for primary
healthcare delivery and the use iswidespread in developing countries
(Badami et al., 2003).
Traditional medicine is also cheaper
than modern medicine. It issometimes the only affordable source of
healthcare especially for theworld’s poorest patients. In addition to
its cheaper price, traditionalmedicine has a wider acceptability among
the people of developingcountries than modern medicine due partly to
inaccessibility of modernmedicine. But the major contributing factor is
the fact that traditionalmedicine blends readily into the socio-cultural
life of the people in whoseculture it is deeply rooted. Furthermore,
traditional medicine remainspopular because the practitioners have
wisely formed an importanteconomic contract to the mutual benefit of
their practice and thepopulation they serve (Gidday et al.,
2003). Apart from the advantages oftraditional medicine, many problems
must be tackled to maximize thepotential of traditional medicine as a
source of health care (WHO, 2002).Perhaps one of the greatest arguments
against traditional medicine todayis the lack of scientific proof for
its efficacy. There is no thoroughscientific investigation on most of
the claims made by the traditionalmedicine practitioners (Sofowora,
1993).In 1964, the OAU set up the Scientific and Technical
ResearchCommission to initiate research on the proof of efficacy of
medicinalplants. This initiative has greatly enhanced the development of
medicinalplant research but there are challenges facing institutions
conductingresearch on traditional medicine. One of the main challenges
is lack ofcoherent national health policies and development plans that
will includetraditional medical research (AACHRD, 2002). In addition,
utilization ofherbs may possibly expose the patient to unknown dangers
(Gidday etal., 2003). Other problem with traditional medicine
is the criticism thattraditional medicine lack hygiene and precise
dosage (Sofowora, 1993).
TRADITIONAL MEDICINE AND DRUG DISCOVERY FROM PLANTS
For centuries, people have used plants
for healing. Until recently, plantswere important sources for the
discovery of novel pharmacological activecompounds, with many drugs
being derived directly or indirectly fromplants (Cordell, 2000). Many
modern drugs have their origin in theethno-pharmacology (Badami et al.,
2003). A survey of pharmacopoeiasof developed and developing countries
was done to determine whetherethnobotanical information did indeed lead
to successful drug discovery.The survey showed that from 122 compounds
identified in the study,80% of the compounds were used for the same (or
related)ethnobotanical purposes. Information based on long-term use of
plantsby humans (ethnomedicine) likely helps to isolate safer
activecompounds from plants than isolating active compounds from
plantswith no history of human use (Lamidi et al., 1995). Thus,
instead ofrelying on trial and error, as in random screening
procedures, traditionalknowledge helps scientists to target plants that
may be medicinallyuseful (Cordell, 2000). Indeed, traditional medicine
is a potential sourceof new drugs and as a source of cheap starting
products for the synthesisof known drugs. Some examples include
reserpine from Rauwolfiaspecies, viablastine from Catharanthus roseus (Sofowora, 1993).