**5. Therapeutic and prophylactic properties of the crops**

### **5.1. Bambara groundnut**

tures and carboxylic group which can inhibit lipid peroxidation are responsible for its ability

The aqueous extract of leaf (LE), fruit (FE) and seed (SE) of *M. oleifera* could significantly inhibit the OH-dependent damage of pUC18 plasmid DNA with an activity sequence of LE > FE > SE. Gallic acid, chlorogenic acid, ellagic acid, ferulic acid, kaempferol, querce‐ tin and vanillin were present in the extracts. The leaf extract was comparatively higher in total phenolics [105.04 mg gallic acid equivalents (GAE/g)], total flavonoids [31.28 mg quercetin equivalents (QE/g)] and ascorbic acid (106.95 mg/100 g) with better antioxidant activity (85.8%), anti-radical power (74.3), reducing power [1.1 ascorbic acid equivalents (ASE/ml)], inhibition of lipid peroxidation, protein oxidation, OH-induced deoxyribose degradation and scavenging power of superoxide anion and nitric oxide radicals than did the FE, SE and standard α-tocopherol [56]. Many gram negative bacteria such as *Erwinia carotovora*, *Enterobacter agglomerans*, *Chromobacterium violaceum* and *Pseudomonas aeruginosa* use N-acyl homoserine lactones (AHLs) signal molecules to monitor their own popula‐ tion density. At a threshold population density, AHLs interact with cellular receptors and trigger the expression of a set of target genes including virulence, antibiotic production, biofilm formation, bioluminescence, mobility and warming, in a process called "quorum sensing" (QS) [57]. The discovery of the QS system and its critical role in bacteria viru‐ lence and survival has revealed a novel way to attack and attenuate bacterial pathogenici‐ ty. The major advantage of this novel strategy for anti-infective therapy is that it circumvents the problem of antibiotic resistance, which is intimately connected to the use of convention‐ al antibacterial agents, as it specifically interferes with the expression of pathogenic traits rather than to impede growth of the bacteria. The efficacy and toxicity of previous reported QS blockers (halogenated furanones) have been important concerns. Hence, attention has been focused on identification of such QS blockers from natural and non-toxic sources for the development of novel non-antibiotic drugs for treating bacterial diseases in humans as well as in other animals. Singh et al. [56] reported that the leaf and the fruit extracts of *M. oleifera* inhibited violacein production, a QS-regulated behaviour in *Chromobacterium violaceum* 12472. This provides evidence on *M. oleifera* as natural antioxidant for its capacity to protect organism and cell from oxidative DNA associated with aging, cancer and denegerative diseases as well as inhibit lipid peroxidation and bacterial QS. Thus, *M. oleifera* may serve as an ideal ingredient for functional food, nutraceutical and bio-pharmaceuti‐

The seeds of *Moringa oleifera* contain 4 (α-L-Rhamnosyloxy) benzyl isothiocyanate and benzyl isothiocyanate. These are antimicrobial agents effective against several bacteria and fungi. The minimal bactericidal concentration in vitro is 40 μmol/l for *Mycobacterium phlei* and 56 μmol/l for *Bacillus subtilis* [58]. Singh et al. [10] identified ten phenolic compounds (gallic acid, pcoumaric acid, ferulic acid, caffeic acid, protocatechuric acid, cinnamic acid, catechin, epica‐ techin, vanillin and quercetin) from defatted *M. oleifera* seed flour. These natural plant phenolics could be a good source of antioxidants and antimicrobials for food and pharma‐

as free radical scavengers [55].

198 Antioxidant-Antidiabetic Agents and Human Health

cal industries.

ceutical industries.

The medicinal role of BGN is mainly based on information obtained from communities in several parts of Africa, where this crop is reportedly responsible and useful for treatment of various ailments. As a treatment for diarrhoea, a mixture of BGN and water from boiled maize are consumed. Raw BGN seeds are chewed and swallowed by pregnant women to alleviate the nausea associated with pregnancy [7]. The medicinal value of the crop have also been highlighted and reviewed by [59]. The following uses of BGN as traditional medicine have been noted by the authors (i) In several countries in sub-Saharan Africa, BGN plays an important role in the diets of especially young rural children as it helps in overcoming the protein deficiency Kwashiorkor; (ii) The Igbos tribe in Nigeria use the seeds for treatment of venereal diseases; (iii) To treat polymenorrhea it is recommended that BGN seeds be roasted before consumption; (iv) The water in which BGN seeds are boiled is used as treatment for internal bruising, and a mixture of water and crushed seeds are prescri‐ bed for treatment of cataracts; (v) BGN seeds have the highest concentration of soluble fibre as compared to other beans; this could contribute to the reduction of heart disease incidence and prevention of colon cancer; (vi) Surveys amongst local communities in northern Côte d'Ivoire revealed that the BGN seeds are mainly used for medical treatments as opposed to other parts of the plant. The seeds are used to treat anemia, ulcers (black BGN variety mixed with an unidentified plant) and menorrhagia during pregnancy (hemostatic drink prepared by a mixture of BGN flour and *Pupalia lappacea* (L.) Amaranthaceae dissolved in water). The traditional uses of BGN to treat several ailments are noteworthy, and present a gap for detailed study on the pharmaceutical value of the crop. This would provide yet another means of highlighting the potential of BGN as an underutilised legume and tap into ways of encouraging more sustained production and use of BGN.

#### **5.2.** *Moringa oleifera*

Besides the rich nutritional value of *M. oleifera* it has curative and prophylactic properties [24]. Almost all the parts (root, bark, gum, leaf, pods, flowers, seed and seed oil) of M. oleifera have been used for various ailments including the treatment of inflammation and infectious diseases along with cardiovascular, gastrointestinal, haematological, hepatorenal disorders, diabetes mellitus, CNS depressant, and for antifertility effect [40]. The plant has been used for the treatment of ascites, rheumatism and for the enhancement of cardiac function. The seed extract have been reported to be administered nasally in diseases like rhinitis and the dried seeds used successfully as an 'anti-allergic' agent by the Ayurvedic practitioners [60]. Mahajan [61] reported an antiarthritic activity of ethanolic extract of seeds of *M. oleifera* against chemical induced rheumatoid arthritis as well as an antiasthmatic activity against immune-mediated inflammatory responses in rat [62]. *M. oleifera* seed extract can act against CCl4-induced liver injury and fibrosis in rats by a mechanism related to its antioxidant properties, anti-inflammatory effect and its ability to attenuate the hepatic stellate cells activation [63].

**Author details**

Africa

**References**

82-90.

2013).

p1-10.

Victoria Adaora Jideani\*

\*Address all correspondence to: jideaniv@cput.ac.za

and Claudine Florett Diedericks

Department of Food Technology, Cape Peninsula University of Technology, Bellville, South

Nutritional, Therapeutic, and Prophylactic Properties of *Vigna subterranea* and *Moringa oleifera*

http://dx.doi.org/10.5772/57338

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Siddhuraju and others [40] reported that leaf extracts (water, aqueous methanol, aqueous ethanol) were capable of scavenging peroxyl and superoxyl radicals. The major bioactive compounds of phenolics were found to be flavonoid groups such as quercetin and kaempferol. *Moringa* leaves are therefore potential source of natural antioxidants. The ethanol leaf extract of *Moringa oleifera* is used for hypertension [64-66]. The leaves are used as hypocholesterolemic and hypoglycemic agents [64, 67-68]. Additionally, the leaves have been reported for its antitumour [69], antioxidant [46, 54, 70], radio-protective [71-72], anti-inflammatory/diuretic properties [73], antihepatotoxic [74], antifertility [75], antiurolithiatic [76] and analgesic activities [77]. Choudhary and others [78] reported that ethanolic root-bark extract of *M. oleifera* possesses valuable antiulcer, antisecretory and cytoprotective activity in rats and thus can be used as source for an antiulcer drug.

An old report from Southeast Asia says a decoction of bark stimulates menses and is used for "morning after" birth control. In parts of West Africa, *Moringa* leaves or juice are taken for diabetes and high blood pressure [12]. Traditionally, leaves, fruits, roots and seeds of this plant are used for treating abdominal tumors, hysteria, scurvy, paralytic attacks, helminitic, bladder, prostate troubles, sores and skin infections [32].

*Moringa oleifera* possess genotoxicity at a high dose 3000 mg/kg b.wt of the powdered aqueous extract. However, intake is safe at levels ≤ 1000 mg/kg b.wt. [79].
