Moringa oleifera Lam . : A Biofunctional Edible Plant from India , Phytochemistry and Medicinal Properties

Moringa oleifera is a versatile horticulture tree with important medicinal, nutritional and industrial applications, widely distributed and used in India. The Moringa tree originated in India and was introduced to Africa from India and other countries as a health supplement. Almost all parts of the plant have shown nutritional value and are used in India for a variety of food preparations. In India, M. oleifera leaves are available in powder to treat mild malnourishment in children. About all parts like leaves, seeds and pods are used as vegetables. Phytochemicals such as flavonoids, tannins, triterpenoids, saponins, flavonoids, anthraquinones, alkaloids and others, are responsible for the medicinal value of this plant. This species is rich in protein, fatty acids, vitamins and minerals that form part of its quality as superfood. It has been reported to have strong antimicrobial, antioxidant, anti-inflammatory, hepatoprotective, diuretic, anthelminthic and antiurolithiatic properties, among others. People in India use this species to treat common illnesses because of its availability and easy preparation. This review provides information on the significant potential of Moringa and its nutritional, medicinal, pharmaceutical and industrial values.


Introduction
The genus Moringa belongs to the monogeneric family Moringaceae and comprises thirteen species distributed from semi-arid Africa to Asia.Of these, M. oleifera Lam.(Figure 1) is the most commonly known species distributed in the northwest India (Mabberley, 2017;Nadkarni, 1976;Ramachandran et al., 1980;Jahn 1988;Somali et al., 1984;Mughal et al., 1999,).The tree ranges in height from 5 to 10m (Morton, 1991).This tree grows rapidly, with recording growth of 6-7 m in areas with rainfall of less than 400 mm per year (Odee, 1998).Although it is wild in NW India, it can be cultivated in different areas, growing at elevations of up to 1,000 m above sea level on pasturelands, river basins or hillsides.
Moringa oleifera is also known with different names including, horseradish tree, ben oil tree, drumstick tree, miracle tree, and "Mother's Best Friend", Kelor tree (Anwar andBhanger, 2003, Prabhu et al., 2011).This species was introduced to Africa at the beginning of the twentieth century as a health supplement (Muluvi et al., 1999).The ben oil seems to show promise for the manufacture of soap with high washing efficiency.This makes it suitable for poor areas where people cannot afford buying these products but they have the plant available for use.This nutritional plant is little known in the western world despite of being considered one of the world's most beneficial trees due to the potential use of each part of plant (Table 1) either as fodder, vegetable or medicine in South Asia (Odebiyi and Sofowora, 1999).The leaves, fruit, flower and immature pods (Figure 1) of this tree are commonly used as a nutritious vegetable in several countries, making it a great potential food source in dry season areas where food could be scarce.Countries such as India, Pakistan and Philippines (Gopalakrishnan et al., 2016;Anwar et al., 2005;Anwar and Bhanger, 2003;D'souza and Kulkarni.1993)use this species widely.Moringa is being used in diverse culinary ways and as a health supplement (McBurney et al., 2004;Fahey, 2005;DanMalam et al., 2001;Iqbal et al., 2006).A leaf powder from the plant can be used for children with malnutrition, pregnant and lactating woman (Price, 1985).For example, In the Philippines, this plant is commonly used to increase the production of milk in lactating women, hence its name of "mother's best friend"; and it has also been prescribed to patients with anemia (Siddhuraju and Becker, 2003;Estrella et al., 2000).
Interestingly, this species is reported to have natural and organic sunscreens with an SPF value of 2 at low concentrations (2-4%), giving a 50% sun protection (Baldisserotto et al., 2018), a potential alternative for use in children in tropical countries.

Root
Used as a substitute for horseradish To treat tumors, promote digestion, antilithic, antifertility and anti-inflammatory.Beneficial against rheumatism, constipation, kidney pain or back pain.

Medicinal Value
Moringa is known in folk medicine in India (Fuglie, 1999.) because of its versatile medicinal properties and it has been used since ancient times by people.It is recognized for its anti-inflammatory, diuretic, abortifacient, antispasmodic, emmenagogue and ecbolic properties and it has been reported to be useful in the treatment of tumors, leukoderma and biliousness etc. (Das et al., 1957, Shaw andJana, 1982).Interestingly, ethanolic extracts of Moringa leaves seem to have a radioprotection effect against damaged induced by high doses of ionizing radiation (Elwan et al., 2018) showing the versatility and potential uses of this plant.

Antimicrobial Properties
Virtually all parts of this species have shown antimicrobial properties (Caceres et al., 1991;Ali et al., 1999;Senthil Kumar and Reetha 2009); this includes leaves, bark, fruit, root and flowers (Khalil 1996;Tsaknis et al., 1999).This is important because there is a great need for antimicrobial compound in the medical community due to the development of antibiotic resistance.More studies need to be done to evaluate the use of this species and to isolate the proper compounds that can be use in allopathic medicine.

Antioxidant Properties
The antioxidant properties of this species is important to prevent of damage to important macromolecules such as DNA, proteins and lipids so cells can function properly (Ryter et al., 2007;Limon-Pacheco and Gonsebatt, 2009).The seeds and leaves of Moringa are a good source of antioxidants (Chumark et al., 2008) with 65.1 % in methanolic extracts and 66.8% in ethanolic extracts (Lalas and Tsaknis, 2002;Siddhuraju and Becker, 2003).Some studies have shown that quercetin and kaempferol seem to be responsible for this antioxidant activity (Bajpai et al., 2005;Siddhuraju and Becker, 2003).The qualitative properties of antioxidant in Moringa have been highlighted.Sreelatha and Padma (2009) indicated that the antioxidants in both mature and young leaves have a great potential to scavenge free radicals, along with nutritional antioxidants such as Vitamins A, C, and E (Limon-Pacheco and Gonsebatt, 2009).The highest therapeutic value of M. oleifera is further substantiated in terms of its high antioxidant level present in leaves, seeds, flowers and pods (Chumark et al., 2008;Verma et al., 2009;Atawodi et al., 2010).Kumar et al. (2007) demonstrated these antioxidant properties could be responsible for reduction of the chance of cancer development and other damage to the cell.

Anti-inflammatory Properties
The pathophysiology of many diseases, such as diabetes, obesity, hypertension and others can involve immunological responses (Rana et al., 2007).Leaf extracts from Moringa leaf extracts seem to modulate cellular immunity in rats and mice (Sudha et al., 2010;Gupta et al., 2010).Leaf preparations have shown anti-inflammatory properties in rodent models (Sulaiman et al., 2008;Mahajan and Mehta, 2009).Studies suggest that the anti-inflammatory properties are stronger in fruit and seed extracts (Mahajan and Mehta, 2010;Cheenpracha et al., 2010;Muangnoi et al., 2011).

Hypocholesterolemic Activity
Moringa leaves contain phytosterols (Jain et al., 2010); that seem to be implicated in the reduction of cholesterol uptake by the intestines (Lin et al., 2010).It is possible that this could result in a decrease in cholesterol levels and an increase in excreted cholesterol seen in experimental rodents (Mehta et al., 2003;Jain et al., 2010).The high-fiber content (12% w/w) may also play a role in the hypocholesterolemic effect due to enhanced excretion/gastric emptying (Bortolotti et al., 2008;Joshi and Mehta, 2010).

Anti-asthmatic Activity
The Moringa alkaloid moringine closely resembles ephedrine, inducing relaxation of the bronchioles (Kirtikar and Basu, 1975).The seeds and kernels of Moringa have been used successfully for the treatment of bronchial asthma, by decreasing the severity of the symptoms, resulting in the improvement of respiratory problems in patients (Agrawal and Mehta, 2008).

Analgesic Activity
Ethanolic extracts of Moringa fruits have shown good analgesic properties when tested in Male Sprague-Dawley rats (Rao et al., 2008).The authors used the Ugo Basile 37215 analgesia-meter to evaluate pain and adjuvant-induced arthritis to evaluate anti-inflammatory properties.They found strong analgesic activity and anti-inflammatory properties in this plant.Sutar et al. (2008) used Wister male albino rats and tested pain threshold using the licking or paw/jumping response of the animal and the tail immersion method.The authors found that Moringa seems to have a strong analgesic activity.There is a great potential for this plant to be used by people that may not have access to more expensive analgesics but have the plant available for their use.In addition, extracts of this plant could eventually be commercialized for medicinal uses.

Antidiabetic Activity
Experiments in Wistar and Goto-Kakizaki (GK) rats with type 2 diabetes show a positive effect of Moringa leaves, with a significant decrease in blood glucose levels (Ndong et al., 2007).In addition, in high-fat-diet mouse models, the extracts of this plant have shown improved glucose tolerance (Jaja-Chimedza et al., 2018).The lowering blood sugar levels within 3 h after ingestion has been observed (Mittal et al., 2007) and is likely to be due to extracts' inhibitory activity against α-Glucosidase enzyme (Natsir et al., 2018).It is possible that polyphenols such as 3-glycoside, kaempferol glycosides and others (Ndong et al., 2007) could have an effect in this antidiabetic activity.Studies have shown the antioxidant activity of Moringa can rescue apoptosis of beta cells, therefore preventing damage to these cells, leading to the beneficial properties against diabetes (Al-Malki et al., 2015;Mbikay, 2012;Kaneto et al., 1999).Additional studies may lead to the commercialization of Moringa extracts for conventional treatment of diabetes.

Conclusion
This review shows that different parts of Moringa (leaves, flowers, fruits and seeds) possess a great variety of compounds with high nutritional and medicinal content that could make it an ideal complementary and alternative medicine and/or nutritional supplement.The presence of antimicrobial compounds could lead to the development of alternative treatments against infectious diseases.Research has shown that every part of the plant has some medicinal application that could be further develop to produce more affordable medicines.M. oleifera is nutritional and medicinally very active against free radicals formed during oxidative stress due to the strong phytochemical constituents present in virtually all parts of the plant.There is a great potential for the widespread use of this plant.

Table 1 .
Common uses of different parts of Moringa