Diabetes is a burning issue all over the world. World health organization has shown concerns on the prevalence and incidents of diabetes. In USA, 29.1 million people or 9.3% of the population; diagnosed or undiagnosed have diabetes. (CDC, 2012). As per National Diabetes Fact Sheet, 2011 215, 000 people in USA have type-I or type-II diabetes. Thus, diabetes is a disease penetrating all age groups. Treatment of diabetes has a few advancement in the recent past. Apart from general oral hypoglycemic agents and injectable insulin there are islet transplantation surgeries also available for diabetes. There is a wide scope of treatment of diabetes in non-conventional line of treatment. There is an increase in the number of patients opting for herbal drugs for treating diabetes. One such drug is ‘Moringa Oliefera.’ It is a tree with many names depending on the region and geography. Many studies have proven the effects of this plant on beta cells. In this dissertation, the topic of discussion is the effectiveness of novel drugs from the natural product (Moringa Oliefera) used for the treatment of diabetes. Commonly known as drumsticks, ‘The magic tree’ is another name for it because of its properties to counteract diabetes.
It has been a global estimation that 347 million people have diabetes. By year 2030, it is a projection that this disease will be the 7th leading cause of death (World Health Organization). People with diabetes mellitus develop serious health diseases. A few of them are cardiovascular dysfunction, hypertension, stroke, osteoporosis, neuropathy, retinopathy, foot problems and renal vascular diseases (Sowers, et al. 2001; NHS; Asche, 2011). Diabetes is a metabolic disorder that has characteristic high concentration of glucose in the bloodstream. The glucose in the blood comes from ingested food, and the accumulation of glucose occurs due to the insufficient hormone insulin. The hormone insulin controls the level of glucose in the blood. There are two types of diabetes, characteristics of Type 1 diabetes is by the lack of insulin in the bloodstream. The treatment of type I of diabetes is with daily insulin injections. The diabetes Type 2 is the most common form of diabetes, and persistent hyperglycemia is symptom of diabetes mellitus. (Diabetes, UK). The diabetes Type 2 is currently treated with oral medication to control the level of glucose in the blood. Also, the change of lifestyle, physical exercise and the loss of weight can help control this type of diabetes. The drugs available in the market to treat diabetes Type 2 includes the Biguanides and Metformin that decrease the level of glucose released from the liver. The sulfonylureas, Meglitinides, D-Phenylalanine and DPP-4 Inhibitors Derivatives help activate the cells of the pancreas to produce insulin. The inhibitors Alpha-glucosidase slow down carbohydrates metabolism in the blood. The Thiazolidinediones Pioglitazone (TZDs) sensitize the body to insulin. These drugs help control the levels of glucose in the bloodstream of people with diabetes. However, these medications cause unpleasant side effects. Major side effects include diarrhoea, gas, loss of appetite, edema, bloating, upset stomach, skin rash, low glucose in blood, constipation nausea, upper respiratory infections (Joslin Diabetes Center). The side effects of diabetic drugs lower the quality of lifestyle of diabetic patients. Because of the lack of medication with less side effects to treat diabetes, it is important to find new therapeutic drugs to treat diabetic patients.
The plant Moringa oleifera is and edible plant that is native from the sub-Himalayan areas. The plant’s roots, leaves, seeds, bark, fruits and flowers have medicinal and nutritional properties. M. oleifera plant is useful as an alternative medicine to treat diabetes and many other diseases. The leaves of Moringa oleifera are rich in calcium, potassium, iron, vitamins A and D, phosphorous and essential amino acids. In addition, this plant has antioxidants compounds such as carotene, flavonoids and vitamin C (Mbikay, 2012). The medicinal properties of Moringa oleifera is due to an especial combination of flavonoids and phenolic acid including Quercetin, zeatin, kaempferol, caffeoylquinic acid, beta-sitosterol (Anward, et al. 2007). The characteristic phytochemical compounds with hypoglycaemic properties are not yet available. Several studies using animal models and human volunteers showed the benefits of Moringa oleifera to control the glucose in the blood. However, the studies were subjective with only use of the powder of leaves. Dièye, et al. (2008) performed a cross-sectional survey of people that was using Moringa oleifera to treat diabetes. In this study, only 65% of people answered that this plant was effective to treat diabetes, however 20% of people mentioned had side effects. Kumari et al, (2010) performed studies in human subjects using the leaves of Moringa oleifera, the participants took 8g of leaves powder during 40 days. Interestingly, the authors observed a decrease in blood glucose and lipid levels. The authors reported no side effects in the participants. The improvement in glucose tolerance was evident. In these studies, it was used the whole leaves of Moringa oleifera, without knowing the bioactive compound with anti-diabetic properties. This plant has a complex phytochemical compounds that can have side effects when using inappropriately (Dièye, et al. 2008). Taken together, these scientific studies suggest that Moringa oleifera have chemical compounds that are useful for the development of new therapeutic drugs to treat diabetic patients. Then, it is important to isolate and characterize the chemical compounds of leaves to identify the bioactive compounds with hypoglycemic properties.
2.0 INTRODUCTION ON DIABETES
Diabetes is a metabolic disorder. The word meaning of ‘Diabetes’ is from original Greek word mellitus, meaning ‘Like Honey.’ It is a disorder in which the consistency, taste and density of the patient’s urine is like honey. The causative mechanism of diabetes mellitus is dysfunctional glucose metabolism. In diabetes, the blood glucose level is high. There are a number of various mechanisms responsible for diabetes. Unhealthy lifestyle is one of the causative factor for this disease. People with the sedentary lifestyle, unhealthy diet and alcoholism are more prone to diabetes. Especially, smoking and alcohol are more influential on the diabetes causing metabolism. Diabetes is a chronic metabolic disorder, resulting from insulin deficiency with prominent symptoms like hyperglycemia, dysfunctional metabolism of protein, lipid, carbohydrates and risk of vascular complications. Diabetes is not a single disease; it is a group of different diseases and symptoms.
The function of the pancreas in the body is endocrine and exocrine. The endocrine pancreas produces insulin, glucagon and somatostatin from beta cells and alpha cells respectively. These hormones work with counter mechanism with regulation from hypothalamus. The function of insulin is to resupply the glucose to the cells. Insulin maintains the blood glucose level by providing glucose molecules to the cells. On the contrary, glucagon releases glucose from the stored glycogen and fat cells from the liver. This way glucagon increases the blood glucose level. In a normal condition, the opposite functionality of insulin and glucagon maintains the normal level of glucose level for optimum body function. However, in diabetes the function of beta cells of the pancreas producing insulin is under compromise. The depleting levels of insulin cannot stop the increasing glucose in the blood stream, causing diabetes mellitus. An individual is diabetic when the blood glucose levels are as follows: Blood glucose ≥126mg/dL after an overnight fast, and ≥200mg/dL 2h after an oral glucose intake of 75g (oral glucose tolerance test, OGTT; Alberti and Zimmet, 1998). There are two types of DM. Type 1 DM (T1DM) results from autoimmune destruction of pancreatic β cells and represents only 5% of all cases; type-2 DM (T2DM) is the most common form of the disease. In its early stages, T2DM is characterized by chronic hyperglycemia and increased levels of insulin, due tissue damage sensitivity to insulin and the compensatory secretion of the hormone by islet β cells. Its progression involves a complex grid of intermingling cellular and functional modifications leading to β cell failure. Gluco-toxicity and lipo-toxicity are the most frequently raised mechanisms for the failure of beta cells (Robertson et al., 2004).
There may be many causes for the incapacitation of beta cells, accidental physical injuries, hormonal imbalance, genetic predisposition or chronic unhealthy lifestyle and diet are a few of the causes. According to Lawrence Dolan, (2006) there are increased incidence of non-insulin-dependent diabetes mellitus among adolescents. The objective of the study was to determine whether an increase in the cases of non-insulin-dependent diabetes mellitus (NIDDM) has supplemented the upsurge in obesity in the pediatric population. In an adult population, NIDDM has a larger contribution in increasing obesity. In the observational study of 1027 patients, a review of data was according to the National Diabetes Data Group. At the end of the study, it was clear that the increase incidents of Non-Insulin Dependent Diabetes Mellitus (NIDDM) is usually in association with the increased number of obesity.
There are three major types of diabetes, Type-I, Type-II and Gestational diabetes. Increased level of glucose in plasma is Hyperglycemia. Lack of insulin causes hyperglycemia, which leads to glycosuria resulting into osmotic diuresis. Due to osmotic diuresis, the essential minerals like sodium, potassium level is under depletion.
Juvenile diabetes occurs before the age of 30. It is an auto-immune disease of beta cells of the pancreas. The insulin production in such patients is low since the birth due to genetic predisposition. Patients with juvenile diabetes mellitus have to rely on external insulin for maintenance of glucose level. Type-II diabetes usually, occurs after the age of 40, here the insulin level fluctuates in the body. Abnormalities of glucose-receptors in beta cells forces them to respond to the higher glucose concentration. The treatment of diabetes ranges from oral hypoglycemic agents to injectable insulin supplements. Diabetes mellitus is a disease that is manageable with moderate quality of life.
The oral hypoglycemic agents range from insulin secretagogue, an insulin sensitizer, alpha-glycosidase inhibitors, meglitinides, biguanides, and thiazolidinediones. Insulin secretagogue drugs act by promoting insulin secretion from beta cells, reducing serum glucagon concentration and potentiation of insulin action on target tissues. The popular example of insulin secretagogue drugs is Sulphonylurea. Insulin sensitizer is the class of drugs that increases insulin uptake, and utilization by tissue. Rosiglitazone and pioglitazone are a few of the examples of insulin sensitizer group. Alpha-glycosidase inhibitors act by delaying the digestion of carbohydrates, inhibiting intestinal alpha- glycosidase and reducing post-prandial increase in blood glucose. Meglitinides bind to the same KATP channels as Sulphonylurea to cause insulin secretion. Biguanides increase peripheral glucose utilization, inhibit gluconeogenesis and reduces glucose absorption from the digestive tract. Thiazolidinediones act by reducing hepatic glucose output, increase glucose uptake and oxidation in muscles. Thiazolidinediones are not responsible for hypoglycemia. According to Norah, 2002, in a cross-sectional study, use of herbal medication in the treatment of diabetes mellitus was the topic of evaluation. The frequency of the use of the herbal medication and demographic characteristics of the use was additional objective of the study. The result was 98.6% of the patient population under evaluation used alternative herbal medications for their diabetes. From the aforementioned study is a proof that the use of herbal medication in diabetes is not rare. Many people divert their intervention towards herbal stream of medication as an alternative way to fight the disease. Herbal medication seems better intervention considering the harmful Side-effects of the conventional drugs.
Various groups of drugs act on a different physiology to inhibit diabetes. Depending on the patient’s disease and body, the right choices of medicine can control diabetes. However, there are potential side-effects of each of these drug classes. Long exposure to these drugs can damage internal organs like liver, digestive tract and spleen. These drug classes can help keeping diabetes mellitus at bay. They cannot cure the disease completely. There are many natural plant derivatives to control diabetes. Many of the herbal plants have natural anti-oxidants and hypoglycemic agents. As an alternative medicine, these plants can be helpful in tackling diabetes. Turner, 1998 states that coronary artery disease is in association with NIDDM. There are a few complications of prolonged diabetes. Most of the complications are vascular. Diabetic cardiopathy, diabetic neuropathy and diabetes retinopathy are three major complications of diabetes mellitus. 3055 patients with NIDDM and risk factors like smoking, alcoholism, high cholesterol were the target population. The conclusion of the study proves the association of coronary heart disease with NIDDM.
3.0 INTRODUCTION ON MORINGA OLEIFERA
Moringa is a plant that is native to some parts of Eastern Asia, India, Pakistan and Afghanistan. It is also available in the tropics. The leaves, bark, flowers, fruit, seeds, and root contains active ingredients. There are much medicinal uses of Moringa. Anemia, pancreatitis, swelling, arthritis, cancer, constipation, etc. are a few diseases where different parts and formulations of Moringa becomes helpful. Moringa is also a remedy to reduce swelling, aphrodisiac, supplement for abortion, and boost the immune system. Some people use it as a nutritional supplement or tonic. I few parts of India, Moringa is a food product and a regular ingredient of curries. In alternative medicinal systems of India, China and Gulf countries, it is a potential drug for treating many common ailments. According to world-Agro forestry, 2009 Moringa is a deciduous tree growing up to 10 meters in height. Its bark is corky, soft, thick and deeply fissured. The wood is soft. The leaves are tripinnate, 30.5cm long; leaflets elliptic and alternate with opposite pinnae. Flowers are bisexual, irregular, fragrant, white and loose axillary panicles available throughout the year. The fruit has a common name as ‘Drumsticks.’ Fruits are pod, triangular, ribbed, pendulous, greenish, 22.5-50.00 cm or more in length. Slightly restricted at the intervals and slightly tapering towards the end. Seeds are trigons, winged (flowers in February-March and fruits in March –April). A few preparations of Moringa oleifera parts useful in folk medicine for the treatment of diabetes (Dieye et al., 2008) in T2DM patients. Five studies aimed at verifying the properties of M. oleifera using leaves were identified in the scientific literature (Ndong et al., 2007b; Jaiswal et al.,2009) (William et al., 1993; Kumari, 2010; Ghiridhari et al., 2011). A few of them were animal studies, and few were on diabetic patients.
Moringa oleifera, (Moringa pterygosperma Gaertn) is a member of the Moringaceae family. The Moringaceae family includes 12 other species (Olson, 2002). It is found in native of the northern parts of India, (Ramachandran et al., 1980).
Moringa oleifera is a plant useful in regular cuisines of the host regions. A wide variety of nourishing and remedial features are available in M. oleifera. A few of them are available in its roots, bark, leaves, flowers, fruits, and seeds (Ramachandran et al., 1980; Anwar et al., 2007; Kumar et al., 2010). Phytochemical analyses shows richness in potassium, calcium, phosphorous, iron and vitamins A. There are other micro-nutrients like vitamin D, essential amino acids, as well as such known antioxidants such as β-carotene, vitamin C, and flavonoids (Bennett et al., 2003; Aslam et al., 2005; Manguro and Lemmen, 2007; Amaglo et al., 2010; Gowrishankar et al., 2010).
The therapeutic use of M. oleifera parts in the Indian subcontinent dates back to Ancient times. In Indian traditional medicine the therapeutic use of M. Oleifera appears to have been known by the wide population (Thurber and Fahey, 2009; Torimiro et al., 2009). However, that is not true and in other parts of the world. Indian medicinal system ‘Ayurveda,’ the name of M. Oleifera is ‘Shigru.’ M. oleifera is supposed to alleviate disease of nerves, constipation, pancreas and urinary system. A search on the Internet, using the Google browser and the words moringa, drumstick, or malunggay as keys within page titles, reported a huge amount of websites. Most of these sites describe this plant as a good medicinal plant for alleviating malnutrition and a vast range of diseases. There are many other names of this plant available in various sources. A few of them are Miracle Tree, Tree of Life, Mother’s Best Friend, God’s Gift to Man and Savior of the Poor. In many regions of Africa, it is widely consumed for self-medication by patients affected by diabetes. M. oleifera is also useful in hypertension, or HIV/AIDS (Dieye et al., 2008; Kasolo et al., 2010; Monera and Maponga, 2010). In a similar search of the PubMed database of biomedical publications, merely 163 papers were fetched; 76% of them were in publication in the last decade (Figure (Figure1).1). A similar search produced about 1250 articles; the vast majority of articles were in scientific journals. However, they were not indexed in PubMed, and a good number in non-peer-reviewed book chapters, patents, citations, or other documents. Clearly, the plant M. Oleifera have a large range of medicinal properties with a lot of potential active ingredients, essential oils and nutritional values. But the popularity of the plant among research community is not satisfactorily rising.
Major chemical constituents of the different parts of M. Oliefera contains many essential active ingredients. The bark contains sterols and terpenes (bayrenol).
The whole tree has moringine, moringinine, bayrenol, indole acetic acid, pterogospermine, carotene, etc. chemicals. The root, bark, stem-bark, leaves and fruits of M. Oleifera are rich with all the active chemicals and are major parts containing the medicinal properties. Moringa tree is a good source of essential amino acids like methionine and cysteine. Other parts of the tree are a good source of various purposes. According to Gupta, 2012 the pre- clinical studies of Moringa Oleifera on diabetic rats showed protective effects against diabetes. M. oleifera showed antioxidant activity. 4 (a-L-rhamnosyloxi) isothiocyanate showed antimicrobial activity (Ind. J. Exp. Biol; 1981) and anti-bacterial activity (Phillipp. J. Sci., 1990) (Bhatnagar et al; 1961 and Bhavasar 1965). Juice from the leaves and stem bark of M. oleifera inhibited Staph aurus (Bhawasar et al; 1965). The bark extracts showed anti-fungal activity against Micro. Gypseum, Tricho. Mentagrophites, Candida albicans and Helmin. Sativum (Bhatnagar et al., 1961). 50% ethanolic extracts of root bark showed anti-viral activity. (Dhar et al., 1968 and Babbar et al., 1970). M. Oliefera root extract (50% ethanolic) at a dose of 200 mg per kilo led to foetal resorption in 60% female pregnant rats. (Prakash and Mathur, 1976). Ethanolic extract (50%) of the fruit, root and root bark were also found to have spasmogenic effect on the isolated guinea pig ileum. (Dhar et al., 1968). In a controlled study with untreated T2DM patients, William, (1993) examined how M. oleifera addition to a standardized meal, taken after an overnight fast, affected the oral glucose load. Compared to the glucose load, standard meals with or without vegetable supplements induced a significantly lower rise in PPPG (glycemic response) as derived from AUCs. However, when leaf-supplemented meals were compared to standard meals, only the M. oleifera leaf-supplemented meal elicited a lower response (−21%, P<0.01). Plasma insulin AUCs
The alcoholic extracts of the root bark showed anti-inflammatory activity against formalin-induced rat paw edema. There was implantation of cotton palate and granuloma pouch in doses of 500, 750 and 1000mg/kg oral doses respectively in albino rats. It also showed analgesic activity (Singh et al., 1972). The seed extract agglutinated blood cells of various animals (Sathe et al., 1970). The alcoholic extract of the leaves caused an initial rise in B.P. in mongrel dogs and cats. The rise in B.P. was before a gradual fall lasting for a considerable duration. And it also potentiated the response of nor-epinherine on B.P. and nictitating membrane. Its reaction on B.P. suggested the presence of potent adrenergic neuron blocking substance(s) in the alcoholic extract (Singh et al., 1976). The fruit extracts of M. concanensis showed the LD50>1000mg/kg (Aswal et al; 1984 b).
Jaiswal, 2009 claimed the use of M. oleifera as an ethno-medicine to treat diabetes mellitus. In the study, variable doses of injectable aqueous extracts of M. oleifera on the diabetic animals showed reduction in FBG and PPG levels by 69.2 and 51.2%. The total protein, body weight and hemoglobin increase by 11.3, 10.5 and 10.9% respectively after 21 days of treatment. The aim of the study to evaluate the effect of M. oleifera on glycemic control, hemoglobin, total protein, urine sugar, and urine-protein with body weight was invariably a success in this study. The effect of M. oleifera on the diabetes was evident. The leaves of Moringa contains Quercetin and chlorogenic acid, as well other phytochemical compounds with anti-diabetic properties. In an article by Mahmoud MF, 2013 it is clear that Quercetin protects against diabetes-induced exaggerated vasoconstriction in rats. The results showed that Quercetin protected against diabetes-induced inflated constrictions of the bold vessels and depleted the increased blood pressure. In addition, Quercetin repressed diabetes-related adventitial leukocyte infiltration, endothelial pyknosis and increased collagen deposition. The decrease in serum level of both TNF-α and CRP and restraint of aortic NF-κB by Quercetin in both models of diabetes conveyed the result of the study. Quercetin did not affect glucose level in any of the used diabetic models. Protective effect of Quercetin is in mediation by its anti-inflammatory effect rather than its metabolic effects. The Chlorogenic acid stimulates glucose uptake in skeletal muscle through the activation of AMPK. (Khang Wei Ong, 2013).
4.0 PHYTOCHEMICAL COMPOUNDS OF MORINGA OLEIFERA
The phytochemical compounds of Moringa oleifera with pharmaceutical interest are glucosinolates, flavonoids and phenolic acid. The content of these compounds varies with the place of cultivation, climate and the collection of plants. The chemical compounds with pharmacologic interest are glucosinolates and their hydrolyzed compounds isothiocyanates, thiocyanates, nitriles. The information is available about these compounds that they have antihypertensive properties. The phenolic compounds, flavonoids and phenolic acids have antioxidant properties that can inactivate free radicals that can be damaging the cells of the pancreas. One compound that has been found abundantly in the leaves of Moringa Oleifera is Quercetin, which has antioxidants properties (Mbikay, 2012). The study of Rivera, et.al 2008 using a rodent model, found anti-obese effects, improved hypertension and dyslipidemia. Soliman, G.Z.A. (2013) administered the leaves of Moringa oleifera in powder to diabetic rats, and found reduced glucose in the blood. Interestingly, these authors did not find toxicity Moringa in the rodents. They suggested that Moringa has the direct effect on the utilization of glucose by tissues. Also, another mechanism proposed is the inhibition of the hepatic glycogenesis, and the inhibition of the absorption of glucose by muscle and adipose tissue. Furthermore, the authors proposed that Moringa oleifera can simulate the cells of the pancreas though the terpenoids. These studies demonstrated that Moringa has phytochemical active compounds in the leaves with anti-hyperglycemic properties that require illumination.
Because of the chemical complexity of the M. oleifera medicinal formulations used in the studies, their ostensible therapeutic effects could be due to the joint actions of various bioactive mechanisms found in the plant. These mechanisms are with inclusion of trace metal ions, vitamins, alkaloids, carotenoids, polyphenols, fats, carbohydrates, and proteins (Coppin, 2008; Amaglo et al., 2010). Some compounds may collectively affect broad aspects of physiology, such as nutritional absorption and processing, redox state, or immunity. Moringa oleifera leaves have a huge amount of phytosterols such as β-sitosterol (Jain et al., 2010). These compounds are known to reduce intestinal uptake of dietary cholesterol (Lin et al., 2010). They could partly account for the reduction of plasma cholesterol, and the rise of fecal cholesterol observed in numerous studies (Mehta et al., 2003; Jain et al., 2010). M. oleifera leaf powder also contain about 12% (w/w) fibers (Joshi and Mehta, 2010). Dietary fibers reduce gastric emptying (Bortolotti et al., 2008). The actions of dietary fibers of M. oleifera are effective on the greater stomach content. The improved OGTT response (Ndong et al., 2007b), as well as the progressive improvement of PPPG levels in treated T2DM patients is also an improvement. (Ghiridhari et al., 2011).
Moringa oleifera is rich in compounds containing the simple sugar, rhamnose and the unique group of compounds called glucosinolates and isothiocyanates (Fahey et al., 2001; Bennett et al., 2003). The stem bark has been reported to contain two alkaloids, namely moringine and moringinine (Kerharo, 1969). Vanillin, β-sitosterol, β-sitostenone, 4-hydroxymellin and octacosanoic acid have been isolated from the stem of M. oleifera (Faizi et al., 1994a). Purified, whole-gum exudate from M. oleifera has been found to contain L-arabinose, -galactose, -glucuronic acid, and L-rhamnose, -mannose and –xylose. While a homogeneous, degraded-gum polysaccharide consisting of L-galactose, -glucuronic acid and L-mannose is obtainable on mild hydrolysis of the whole gum with acid (Bhattacharya et al., 1982). Flowers contain nine amino acids, sucrose, D-glucose, traces of alkaloids, wax, quercetin and kaempferat; the ash is rich in potassium and calcium (Ruckmani et al., 1998). They have also been reported to contain some flavonoid pigments such as alkaloids, kaempherol, rhamnetin, isoquercitrin and kaempferitrin (Faizi et al., 1994a; Siddhuraju and Becker, 2003). Antihypertensive compounds thiocarbamate and isothiocyanate glycosides have been isolated from the acetate phase of the ethanol extract of Moringa pods (Faizi et al., 1998). The cytokinins have been shown to be present in the fruit (Nagar et al., 1982). A new O-ethyl-4-(α-L-rhamnosyloxy) benzyl carbamate.
An informative historical account of research in the phyto-chemistry of M. oleifera prior to 1995 is available in Saleem’s doctoral thesis available on-line (Saleem, 1995). Since then, the research has been expanded and refined, not only on the chemical structures of plant molecules, but also on their nutritional and medicinal properties. A few of the major medicinal interest are three structural classes of phytochemicals: glucosinolates, flavonoids, and phenolic acids. (Saleem, 1995; Bennett et al., 2003; Lako et al., 2007; Manguro and Lemmen, 2007; Coppin, 2008; Amaglo et al., 2010; Kasolo et al., 2010). Their content in M. oleifera leaves varies somewhat with the geographic and climatic conditions. Under these conditions, the plant was under development. The processing methods for the collected leaves were also under the progress. (Bennett et al., 2003; Coppin, 2008; Mukunzi et al., 2011).
Glucosinolates are characterized by β-thioglucoside N-hydroxysulfate motif. In M. oleifera leaves, most phytochemicals of this class carry a benzyl-glycoside group linked to the single carbon of the motif. The most abundant of them is 4-O-(α-l-rhamnopyranosyl-oxy)-benzylglucosinolate, otherwise known as glucomoringin (Amaglo et al., 2010). Enzymatic hydrolysis of the glucosinolate motif of members of this class leads to the formation of corresponding isothiocyanates, thiocyanates, or nitriles. Several of these by-products have been shown to possess antihypertensive properties (Faizi et al., 1992, 1994, 1998). In the studies reviewed in this report, no acute or sub-acute toxicity was reported following treatment with M. oleifera leaves at the dosage used.
Identification of phytochemical groups in the extracts the qualitative methods already established to test for classes of compounds in plant extracts by Ciulei (1964) and Chitravadivu et al. (2009) were under progress. The substances that went under the testing phase included: Alkaloids, steroids and triterpenoids, tannins, anthracenosides, reducing sugars, flavones, saponins and coumarins which are reported to have biological activities on animal tissues. The dry extracts of M. oleifera leaves, ether, ethanol and water extracts were useful to determine the compounds. Test for alkaloids One milligram of dried extract was dissolved in six props of 2% hydrochloric acid. The solution was in division of three aliquots; to the first portion which acted as a reference, 2 ml of distilled water was added. There are many studies available in the research community assessing a wide range of phytochemical activities of active ingredients of M. Oleifera on variety of diseases. Some of the research studies have evidence of potential activities of M. Oleifera as antihypertensive, diuretic and cholesterol lowering (The Wealth of India, 1962; Dahot, 1988). There were evidence of M. Oleifera being effective on hypertension (Faizi et al., 1994a; 1994b; 1995). Another study on the ethanol and aqueous extracts of whole pods and its parts, i.e. coat, pulp and seed revealed that the blood pressure lowering effect of seed was more pronounceable. These studies were comparable with results in both ethanol and water extracts indicating that the activity is widely distributed. (Faizi et al., 1998). Activities. Antispasmodic, antiulcer and hepatoprotective activities of M. Oleifera is evident in the study of (Caceres et al., 1992) and (Gilani et al., 1992; 1994a; Dangi et al., 2002). Antitumor and anticancer activities of M .oleifera is evident in the study that was under execution by (Murakami et al., 1998). Antibacterial and antifungal activities of Oleifera is apparent in the variety of studies of (Eilert et al., 1981) and (Nikkon et al., 2003). The bark extract has been shown to possess antifungal activity (Bhatnagar et al., 1961).
The juice extract showed anti-bacterial effects on the microorganisms like Pseudomonas aeruginosa and Staphylococcus aureus, (Caceres et al., 1991). A recent report showed that M. oleifera leaf may be applicable as a prophylactic or therapeutic anti-HSV (Herpes simplex virus type 1) medicine. These leaves may be operative against the acyclovir-resistant variant (Lipipun et al., 2003). The observations depicts some collective medicinal uses of different parts of this plant. The flowers and leaves also are measured to be of high medicinal value with anthelmintic action (Bhattacharya et al., 1982). An infusion of leaf juice was shown to reduce glucose levels in rabbits (Makonnen et al., 1997). According to the Wealth of India, 1962; Padmarao et al., 1996; Dahot, 1988; Ruckmani et al.,(1998), the roots of M. Oleifera are Antilithic, rubefacient, vesicant, carminative. The leaves also have antifertility, anti-inflammatory and stimulant in paralytic afflictions. The leaves act as a cardiac/circulatory tonic, useful as a laxative and abortifacient. They are helpful in treating rheumatism, inflammations, articular pains, lower back or kidney pain and constipation. As per the studies of Morton, 1991; Fuglie, 2001; Makonnen et al., 1997; The Wealth of India, 1962; Dahot, 1988, the leaves of M. Oleifera are Purgative, applied as poultice to sores and rubbed on the temples for headaches. They are also useful for piles, fevers, sore throat, bronchitis, eye and ear infections, scurvy and catarrh. The leaf juice is believed to control glucose levels and applicable to reduce glandular swelling. The researches of Bhatnagar et al., 1961; Siddhuraju and Becker, 2003 states that the stem bark of M. Oleifera is rubefacient, vesicant and used to cure eye diseases. It is also useful for the treatment of delirious patients, prevent enlargement of the spleen and formation of tuberculous glands of the neck. It can be useful to destroy tumors and to heal ulcers. The juice from the root bark is put into ears to relieve earaches and also placed in a tooth cavity as a pain alleviator, and has anti-tubercular activity. Fuglie, 2001 stated that the gum of the plant is used for dental caries, and is astringent and rubefacient. The Gum, mixed with sesame oil, is used to relieve headaches, fevers, intestinal complaints, dysentery, and asthma. It is sometimes used as an abortifacient, and to treat syphilis and Rheumatism. Studies of Nair and Subramanian, 1962; Bhattacharya et al., 1982; Dahot, 1998; Siddhuraju and Becker, 2003; Mehta et al., 2003 showed that the flowers of M. Oleifera are of High medicinal value as a stimulant, aphrodisiac, abortifacient and cholagogue. It is useful to cure inflammations, muscle diseases, hysteria, tumors, and enlargement of the spleen; lower the serum cholesterol, phospholipid and triglyceride. It also reduces the levels of VLDL, LDL cholesterol to phospholipid ratio and atherogenic index. It decrease lipid profile of liver, heart and aorta in
