The use of natural products with therapeutic properties is as ancient as human civilization
By Ashwani Kumar
| November 5th 2009 02:51 AM | Print
The use of natural products with therapeutic properties is as ancient as human civilization and these natural products are the foundation of preventing and curing diseases. Numerous present day medicines of the western world have been developed based on traditional medicines by studing and recognozing the mechanisms of action and their receptors.
This interest in drugs of plant origin is due to several reasons, eg, abusive or incorrect use of synthetic drugs results in side effects and other problems, a huge part of the world’s population does not have access to conventional pharmacological treatment, and folk medicine and ecological awareness suggest that “natural” products are harmless. Many scientific studies of traditional medicines have lead many ways of screening for novel bioactive compounds and to design and chemically synthesizing similar structures.
Utilization of plants for medicinal purposes in India has been documented long back in ancient literature. Right from its beginning, the documentation of traditional knowledge especially on the medicinal uses of plants, has provided many important drugs of the modern day. Due to its varied geographical and agro-climatic regions, India is a rich source of plant and animal wealth. Besides its wide-ranging biodiversity, it has a varied cultural heritage too. Ayurveda and Siddha are of Indian origin and accounted for about 60% health care delivery in general and about 75% of rural Indian population depends on these traditional systems.
From ethanobotanical survey, it is clear that indigenous peoples use a wide range of plants therapeutically to maintain their health. Elderly people, whose empirical knowledge is respected by everyone in the village, practice traditional phytotherapy. They are familiar with the sign and symptoms of various common diseases and ill conditions and claimed to cure or relieve symptomatically these maladies with the locally available plant drugs.
Plants of genus Euphorbia are used in many ethnobotanical remedies in India and as well as other countries. Different parts of many Euphorbia plants are used as medicines by the local traditional healers. Among the different plant parts, the leaves are most frequently used for the treatment of diseases, followed by whole plant, fruit, stem, root, stem and root bark, seed, flower and latex.
The methods of preparation fall into many categories like, plant parts applied as a paste, juice extracted from the fresh plant parts, and powder made from fresh or dried plant parts, some fresh plant parts, and decoction. External applications (mostly for skin diseases, snakebites, and wounds) and internal consumption of the preparations were involved in the treatment of diseases.
Current research on natural molecules and products primarily focuses on plants, they can be sourced, and selected more easily based on their ethno-medicinal use. Use of ethnopharmacological knowledge is one attractive way to reduce empiricism and enhance the probability of success in new drug-finding efforts.
In a process of defense against parasites, bacteria, and viruses, plants produce secondary metabolites, and rely on these chemical for their survival. These secondary metabolites constitute the medicinal value of a plant drug, which produces a definite physiological action on human body. These are synthesized in special cells from primary metabolic and always found only in certain specific plant organ.
Resistance to the traditional antibiotics is a most important global public health problem. Infectious diseases account for approximately one-half of all deaths in countries of tropical regions. In developed nations, in spite of the progress made in the research on microorganisms, incidents of epidemics create enormous public health concerns due to drug resistant microorganisms and the appearance of new disease causing microbes
The basic mechanisms of bacterial resistance include inactivation or degradation of the antibacterial drug by enzymatic action, decline, or alteration of membrane permeability of the bacterial cell to antibiotics, or the modification of the bacterial proteins that are drug targets.
Therefore, screening of new antimicrobial agents from plants poses an enormous challenge and is important especially with the appearance of drug resistant disease strains. The crude extracts of the plants that were selected for making bioassays, many extracts had inhibiting effects on almost all test organisms. Detailed inhibition data of microbial growth in the presence of crude acetone extracts and methanol extracts, as well as the fresh extracts.
In this study, the results obtained indicated that E. coli, S.typhae and B. cereus were the most susceptible bacteria to almost all E.hirta extracts. The inhibition zone of S.aureus by Methanolic extract of leaves of E.hirta was 13.6mm at concentration of 10mg/mL. The maximum inhibition zones for B.subtilis (16.4mm) followed by E.coli (15.8mm) and B.cereus (15.2mm), were shown by fresh latex of E.hirta, which is close to the inhibition zone of Ampicilin. MIC of E.hirta extracts were also recorded as 0.1 mg/mL in case of B.cereus, S.aureus, and B.subtilis.
Acetone extract of E.tirucalli stem, exhibited more potential activity against S.typhae, S.enteritidis than methanolic extract. B.subtilis and S.aureus exhibited a prominent inhibition zone of 6.8mm at a concentration of 10mg/mL, followed by E.coli and S.tyhae at ¬6.7mm at a volume of 10mg/mL.
The E.tirucalli latex inhibited the growth of all Gram-positive bacteria’s by a inhibition zone ranging 15-18mm. latex also inhibited S.aureus at 0.05 mg/mL, which was the lowest concentration used to inhibit the growth and described as MIC in this study.
The maximum inhibition of the Acetone extract of E.pulcherrima stem against E.coli, K.pneumoniae, and S.typhae ranged at 8.5-6.7mm at conc. of 10mg/mL. While B.cereus and B.subtilis ranged between 5.2-5.3mm at 10mg/mL. In case of methanolic extract, root extract showed the maximum inhibition against E.coli ranging at 7.8mm at 10mg/mL, while minimum inhibition was shown by S.typhae at 4.3mm
Root extract of E.thymifolia was proved a less potent extract with very less antimicrobial activity, than any other plant parts. The maximum inhibitory zones recorded by E.coli and S.aureus isolates were between 7.2 to 6.7mm. 10mg/mL of methanolic extract induced a minimum inhibition in case of S.enteritidis as both extracts showed inhibition zone of 2.1mm range.
The inhibitory activity of fresh latex was most promising than any extract or any plant part. The fresh latex of E.hirta showed maximum activity against S.aureus (16.3mm), which is more than Ampicilin (standard antibiotic). This promosing antibacterial activity was followed by E.coli (15.8mm), S.aureus (15.3mm), and B.cereus (15.2), which is also of the range of most standard antibiotics used.
In case of E.tirucalli maximum inhibition zone was shown by E.coli (15.8mm) followed by S.aureus (15.3mm) and B.cereus (15.2mm), which is also in the range of standard antibiotic streptomycin (10µg). B.subtilis was most resistant microbe and did not show any inhibiton.
Latex of E.pulcherrima showed maximum inhibition against S.enteritidis (14.8mm), followed by S.typhae (13.2mm). Minimum inhibition was recorded in case of K.pneumoniae (9.8mm), and S.aureus did not show any inhibition.
E.thymifolia latex was most active against B.subtilis (14.2mm), followed by B.cereus (13.6mm) and S.enteritidis (13.2mm). While it was almost inactive against S.aureus and it did not showed any inhibition.
There are wide varieties of clinical diseases produced by the fungi’s of the genus Aspergillus and Fusarium. In the present antifungal study, Aspergillus spp. were found to exhibit wide-ranging sensitivity to methanol extracts of different plants. Among different solvent systems analyzed, methanol was observed to have highest antifungal activity against all the fungi tested.
In the preliminary antifungal screening, leaf extracts of E.hirta showed more than 13 mm in diameter of the zone of inhibition against Aspergillus niger and Fusarium oxysporum. The MIC of methanolic extract of E.hirta, methanolic extract of root of Euphorbia thymifolia, and methanolic extract of Euphorbia pulcherrima was found to be 0.1 mg/mL while the MIC of methanolic extracts of leafs of Euphorbia tirucalli were 1.0 mg/mL. On further studies, fresh latex of E. hirta was found to be a potential fungi-static.
Therefore, results shows that the extract contains substance that can inhibit the growth of some microorganisms. Other workers have also shown that extracts of some plants inhibited the growth of various microorganisms at different concentrations. The observed antibacterial effects on the isolates is believed to be due to the presence of alkaloids, tannins and flavonoids which have been shown to posses antibacterial properties.
The practitioner, who was able to identify the correct plant species, produced traditional herbal medicines using the old methods. This practice of the traditional practitioner administrating his own medicines is being progressively shifted to herbal drug stores that are profit-oriented. Therefore, there is no guarantee of the authenticity and quantity of plant material used in the preparations.
The quality of such traditional medicines varies extensively and may not even be effective. Therefore, there is a need to select suitable technologies for the industrial production of traditional medicines such that the effectiveness of the preparation is maintained. Traditional methods used have many disadvantages which could be corrected by selecting the suitable technologies.
It is to be stated that the traditional methods were dependent on the status of technology that was available at that time. It therefore follows that these can be modified and improved using the technologies available today to make them more effective, stable, reproducible, controlled and in dosage forms that can easily be transported.
There is need to pay a little more attention to these plants to find out more potential uses such as antimicrobial activities related to them. Through such investigations, many more new potential plant species can be discovered from the unique folklores lying hidden among the traditional communities of other ethnobotanically unexplored areas, and which may be utilized to the well being of human health. These efforts will certainly pay dividends in terms of the discovery of new therapeutic agents of plant origin for many diseases and conditions for which still there are no satisfactory cures in modern medicine.
These plants are all active against one or more of the test organisms. The combination of the ten different test organisms used during this research covers both fungi and bacteria. It includes human pathogens, Gram-positive and Gram-negative bacteria, and some harmful fungal strains. This makes it possible to detect different kinds of growth inhibition by plant extracts.
Therefore, this study was sought to collect information from local population concerning the use of some euphorbious medicinal plants; identify the most important species used and to determine the relative importance of the species surveyed.
This study emphasizes the efficacy of these plants in traditional remedies, and that it inspires people to realize the importance of protecting natural resources for sustainable use, not in the least for its potent pharmaceuticals. This study also illustrates the strong dependence of certain people on traditional medicine and the creativeness in which plants and their secondary metabolites can be utilized. This will not only provide recognition of this undocumented knowledge but will also help in conservation of such rare, gradually vanishing important desert species.