TOXICITY OF BIOACTIVE COMPOUND
The general belief is that plant and
plant products are safer than the synthetic ones. But the fact is that
they are neither safe nor completely poisonous. In low amounts, they may
be ineffective and in right amount they may prove beneficial. Whereas,
high dose and prolonged use may be harmful (Jowell, 1999). The toxicity
in using plant products may be due to various reasons such as:
Inappropriate plant identification.
Furthermore, compared to
synthetic product the amount of information on the safety of herbal
products is limited (Ernst, 1998). Natural products contain many
specific molecular principles in their natural state having no definite
dose and potency data. Therefore, they have variety of influences on
human physiological and biochemical system. Thus, a bioactive compound
must be tested for its toxicity to assess its quality for application in
the health care industry. The effect of plant biomolecules have been
tested on both plant and animal model. Different workers observed the
effect of different bioactive compounds from different sources on
photosynthesis (Haque et al., 1996); pulse seed germination (Brian et
al., 1949; Wright, 1951).
Animal toxicity test have also been
performed by many workers to test the effect on liver (Teschke et al.,
2003; Espritu et al., 2012). Thus research with natural antimicrobials
has far more reaching scope and manyapplications. The antioxidant
properties contribute to the delay of many oxidative-stress related
diseases, such as cardiovascular diseases, cancer, diabetes and
Alzheimer’s (Miron et al., 2010). Moreover, plant phenols inhibits lipid
peroxidation by acting as chain-breaking peroxyl-radical scavengers
(Proestos et al., 2006). Therefore, they can play a protective role for
highly unsaturated lipids against oxidative damage (Miguel 2010), partly
substituting the use of α tocopheryl acetate or preservatives.
Bioactive molecules may also affect lipid metabolism in animal tissues
by showing beneficial effects on the antioxidative enzymes
(superoxide-dismutase and glutalthione peroxidase) activity, as well as
on polyunsaturated fatty acid composition (Hussain et al., 2008).
Flavonoids may also act as pro-oxidants (Heim et al., 2008). After
penetrating the inner cells membrane, flavonoids can be oxidized by ROS
converting into pro-oxidants, which are able to oxidize lipids, proteins
and DNA. This mechanism may lead to late apoptosis or necrosis of
damaged cells, thus playing a “protective†role by eliminating potential
mutants. Other than that it can also be used as herbicide (Sumthong,
2007), as cosmetics (Dharmananda, 2003), as pain killer (Raffauf, 1996),
as medicines in hypertension (Edema and Alaga 2012).
Apart from in
vitro experiments examining the biological activities in vivo
experiments have examined their beneficial impact as dietary supplements
in animal nutrition and also as anticoccidials (Fig 2). Antioxidant
activity Antimicrobial activity Anticoccidal activity Activities
involved Purified compound Uses Feed additives Pharma industry eg:
Growth promoters Food industry Cosmetic industry eg: medicines eg:
preservatives eg: skin products
CONCLUSION
In the end, it can be concluded that study of plants and plant wastes as antimicrobial agents is necessary for gaining insight into flora and their real value, but the use of a standard method for investigation is essential. Likewise, the concentrations or dilutions used must be appropriate with proper information about its safety. Moreover, research in this area should be carried on until the agent responsible for the activity has been determined or, as the case may be, the most active fraction or extracts have been discovered. Finally, different kinds of studies on the mechanisms of action and the pharmacokinetic profile of the extracts should be given high priority.
Showing the various application of a purified bioactive molecule from M.oleifera and J. curcas
Purification (Paper chromatography, Thin layer chromatography, Column chromatography, HPLC) Biochemical characterization (GCMS, IR, NMR) Toxicity test In vivo evaluation Solvent extraction Bioactivity screening M.oleifera and J. curcas.
