What is moringa

Moringa oleifera Lam., is the only genus in the family Moringaceae, commonly known as the ‘drumstick’ or ‘horseradish’ tree, ben oil tree, or benzoil tree. Moringaceae is a single genus family of shrubs and trees, which comprise of 13 species, distributed in the Indian subcontinent (M. oleifera and M. concanensis), Kenya (M. longituba and M. rivae), northeastern and southwestern Africa (M. stenopetala), Arabia, and Madagascar (M. drouhardii and M. hildebrandtii) 1), 2). The Moringa tree grows best in the temperature range of 25–35 °C, under direct sunlight, at an altitude of 500 m, and in slightly acidic to alkaline soil (pH 5.0–9.0); although it can tolerate excess temperature, up to 48 °C, frost in winter, altitude, and a wide variety of soil conditions 3). Moringa oleifera seeds can be planted just after maturity, as the seeds do not undergo dormancy while retaining viability up to 1 year. The tree starts bearing fruits at an age between six and 8 months, with a low fruit set in the initial one to 2 years, however, the yield increases in the subsequent years. India is the largest producer of Moringa oleifera fruits (pods) with an annual production of 1.1–1.3 million tons from an area of 38,000 ha. In India, the state of Andhra Pradesh is the major producer both area-wise (15665 ha) and in production, followed by Karnataka (10280 ha) and Tamil Nadu (7408 ha) 4).

Moringa oleifera Lam., is recognized as a vibrant and affordable source of phytochemicals, having potential applications in medicines, functional food preparations, water purification, and biodiesel production 5). Moringa oleifera is native of the sub-Himalayan mountains of northern India, but currently it is widely distributed in the Americas, Africa, Europe, Oceania and Asia 6), 7). Leaves, flowers, pods and seeds of Moringa oleifera tree are considered a food source of high nutritional value in the African continent and other countries, particularly in India, Philippines and Pakistan 8). Moringa oleifera is an affordable and readily available source of major essential nutrients and nutraceuticals, and it has the potential to eradicate malnutrition 9). The Moringa is often considered as important famine food because of its high resistance to drought and arid conditions owing to their tuberous roots 10). Almost each and every part of Moringa tree is useful for medicinal, functional food preparations, nutraceuticals, water purification, and biodiesel production; including roots, leaves, flowers, green pods, and seeds 11). The immature pods, flowers, and foliage of this tree are used for culinary purposes in different parts of the world 12). The foliage of Moringa oleifera has been established as a rich source of phenolics and glucosinolates 13), minerals 14), tocopherols 15), carotenoids 16), polyunsaturated fatty acids 17), ascorbic acid 18), and folate 19). It is suggested that Moringa oleifera-based food can be used as a significant source of folate, because of significantly higher bioavailability in animals 20). Moringa seed oil (yield 30–40 % w/w), also known as “Ben oil” is used for the production of biodiesel, because of the high content of monounsaturated fatty acids in the form of oleic acid (C18:1) 21). Moringa seed oil is a potential candidate for biodiesel production, as it meets all the main specifications of the biodiesel standards of US, Germany, and Europe 22). Thus, it has great commercial and industrial importance. The low molecular weight cationic proteins, chitin binding protein isoforms (Mo-CBP3), lectins, napins, mabinlins, and other seed proteins extracted from Moringa oleifera seeds are successfully characterized and used in domestic and industrial water purification, and hardness removal because of the potent antimicrobial and coagulant properties 23). One of the most applied properties of Moringa oleifera is the highly efficient coagulating effect of its seeds, which are used in water treatment. These seeds act as coagulants of organic matter suspended in water and are used in water treatment stations for natural cleaning before performing other cleansing processes. Furthermore, seeds have more stable activity in different pH ranges, when compared to aluminum sulfate, the most frequently used coagulating substance in water treatment stations 24). Moringa oleifera has also been assessed for its potential to treat aquaculture waste water. The results have shown the simultaneous elimination of water turbidity, suspended particles and microorganisms, making it suitable to completely or partly replace the usual coagulating agents, leading to economic, health and environmental gains 25).

All parts of the Moringa tree are edible and have long been consumed by humans. Moringa oleifera leaves can be consumed cooked or fresh and they can be stored as dried powder unrefrigerated with no nutritional losses, for several months 26). Moringa is used worldwide in the traditional medicine, for various health conditions, such as skin infections, anemia, anxiety, asthma, blackheads, blood impurities, bronchitis, catarrh, chest congestion, cholera, infections, fever, glandular, swelling, headaches, abnormal blood pressure, hysteria, pain in joints, pimples, psoriasis, respiratory disorders, scurvy, semen deficiency, sore throat, sprain, tuberculosis, for intestinal worms, lactation, diabetes, and pregnancy 27). In many regions of Africa, it is widely consumed for self-medication by patients affected by diabetes, hypertension, or HIV/AIDS 28). Moringa oil has tremendous cosmetic value and is used in body and hair care as a moisturizer and skin conditioner. It has been shown that aqueous, hydroalcohol, or alcohol extracts of Moringa oleifera leaves possess a wide range of additional biological activities including antioxidant, tissue protective (liver, kidneys, heart, testes, and lungs), analgesic, antiulcer, antihypertensive, radioprotective, and immunomodulatory actions 29). Phytochemical analyses have shown that Moringa oleifera is a rich source of potassium, calcium, phosphorous, iron, vitamins A and D, essential amino acids, as well as known antioxidants, such as β-carotene, vitamin C, and flavonoids 30). A wide variety of polyphenols and phenolic acids as well as flavonoids, glucosinolates, and possibly alkaloids are believed to be responsible for the effects of the plant 31).

Moringa oleifera nutrition facts

Among the several nutrients found in different parts of Moringa oleifera, proteins are the most abundant, accounting for approximately 25% of dry weight 32), and at least 19 amino acids have been identified in this plant (Table 4). Furthermore, Moringa oleifera also contains several minerals and vitamins (Table 1 and 2). Lipids are abundant in seeds, mainly stearic acid, saturated palmitic acid and oleic acid, representing about 30% of dry weight 33). The lipidic compounds linolenic acid and palmitic acid are the main constituents of Moringa oleifera leaves. In addition, the high nutritional content found in dried leaves is an indicator of the usefulness of the plant as a food resource 34).

Different parts of the Moringa oleifera tree have been established as being good sources of unique glucosinolates, flavonoids and phenolic acids 35), carotenoids 36), tocopherols 37), polyunsaturated fatty acids (PUFAs) 38), highly bioavailable minerals 39), and folate 40). Fresh leaves dried by lyophilisation were found best suitable to retain maximum content of trans-luteoxanthin (69.4 %), trans-lutein (51.3 %), trans-β-carotene (89.9 %), total carotenoids (60.6 %), α-tocopherol (86.7 %), ascorbic acid (97.8), chlorophyll a (75.5 %) and chlorophyll b (71.1 %) 41). Trans-lutein, trans-β-carotene and trans-zeaxanthin were found as the major carotenoids in fresh leaves, accounting for 36.9, 18.2 and 5.5 mg/100 g, respectively. Similarly, high amounts of ascorbic acid, α-tocopherol and total phenolic content (271.0, 36.9 and 512.0 mg/100 g), respectively were recorded in leaves. α-tocopherol was the most stable vitamin under all drying conditions (86.4 % retention during oven drying), compare to other studied phytoconstituents. Cabinet tray drying was found as efficient as lyophilisation to retain maximum content of total carotenoids (60.1 %), trans-β-carotene (90.1 %), 13-cis-lutein (93.2 %), and antioxidant activity, however, lutein (51.3 %) and ascorbic acid (97.8 %) was best preserved by lyophilisation. Among glucosinolates, 4-O-(a-L-rhamnopyranosyloxy)-benzylglucosinolate (glucomoringin) is the most predominant in the stem, leaves, flowers, pods and seeds of Moringa oleifera 42). Although in the roots, benzyl glucosinolate (glucotropaeolin) is the most prominent. The highest content of glucosinolate is found in the leaves and seeds. The enzymatic catabolism of glucosinolates by the endogenous plant enzyme myrosinase produces isothiocyanates, nitriles, and thiocarbamates that are known for strong hypotensive (blood pressure lowering) and spasmolytic (muscle relaxant) effects 43). Among flavonoids, flavonol glycosides (glucosides, rutinosides, and malonyl glucosides) of quercetin > kaempferol > isorhamnetin are predominantly found in various parts of the tree, except in the roots and seeds. In the leaves, the amount of quercetin and kaempferol was found to be in the range of 0.07–1.26 and 0.05–0.67 %, respectively. Also, among different varieties, the Indian varieties have shown a higher total content of quercetin and kaempferol, compared to the African indigenous samples 44). The potent antioxidant activity Moringa oleifera is attributed to the high concentration of these polyphenols.

Potassium (K), calcium (Ca), and magnesium (Mg) are the predominant minerals in the Moringa oleifera tissues. The highest content of potassium (K) is found in the vegetative parts and immature pods, whereas, leaves and seeds are a rich source of calcium (Ca) and magnesium (Mg), respectively 45). Moringa oleifera is also recorded as having a rich source of iron (Fe) (17.5 mg/100 g). In a bioavailability study conducted on a rat model, Fe from the Moringa leaf was found to be superior compared to ferric citrate, in overcoming iron deficiency 46).

Table 1. Moringa oleifera leaves (raw) nutrition facts

[Source: United States Department of Agriculture Agricultural Research Service 47)]

Table 2. Moringa oleifera pods (raw) nutrition facts

[Source: United States Department of Agriculture Agricultural Research Service 48)]

Table 3. Moringa oleifera leaf powder nutrition facts

[Source: United States Department of Agriculture Agricultural Research Service 49)]

Table 4. Amino acids of leaves, pods and seeds of Moringa oleifera

Amino acids      Moringa oleifera (g/100 g)      
LeavesPodsSeeds
Essential
 Arginine0.4–1.80.364.5
 Histidine0.1–0.70.112.3
 Leucine0.4–2.20.656.7
 Lysine0.3–1.40.151.5
 Methionine0.1–0.50.152.4
 Phenylalanine0.3–1.60.434.0
 Threonine0.1–1.30.393.1
 Tryptophan0.1–5.2ND1.6
 Valine0.4–1.40.544.3
Non-Essential
 Alanine1.8–3.0ND6.9
 Aspartate1.4–2.2ND5.0
 Cysteine0.01–0.10ND2.0
 Glutamate2.5–2.5ND20.9
 Glycine1.3–1.5ND10.9
 Proline1.2–1.4ND4.5
 Serine1.0–1.2ND4.4
 Tyrosine0.01–2.600.081.6

ND: Not determined.

[Source 50)]

Figure 1. Moringa oleifera leaves and powder

moringa benefits

Note: The leaves are the most nutritious part of the plant, being a significant source of B vitamins, vitamin C, provitamin A as beta-carotene, vitamin K, manganese, and protein, among other essential nutrients. When compared with common foods particularly high in certain nutrients per 100 g fresh weight, cooked moringa leaves are considerable sources of these same nutrients. Some of the calcium in moringa leaves is bound as crystals of calcium oxalate though at levels 1/25th to 1/45th of that found in spinach, which is a negligible amount.

The leaves are cooked and used like spinach and are commonly dried and crushed into a powder used in soups and sauces.

Figure 2. Moringa oleifera fruits

Moringa oleifera fruit

Figure 3. Moringa oleifera seeds

Moringa oleifera seeds

Note: The immature seed pods, called “drumsticks”, are commonly consumed in South Asia. They are prepared by parboiling, and cooked in a curry until soft. The seed pods/fruits, even when cooked by boiling, remain particularly high in vitamin C (which may be degraded variably by cooking) and are also a good source of dietary fiber, potassium, magnesium, and manganese.

Figure 4. Moringa oleifera seeds dried

Moringa-Oleifera-Seeds-dried

Note: The seeds, sometimes removed from more mature pods and eaten like peas or roasted like nuts, contain high levels of vitamin C and moderate amounts of B vitamins and dietary minerals.

Figure 5. Moringa Oleifera Oil

Moringa-Oleifera-Oil

Note: Mature seeds yield 38–40% edible oil called “ben oil” from its high concentration of behenic acid. The refined oil is clear and odorless, and resists rancidity. The seed cake remaining after oil extraction may be used as a fertilizer or as a flocculent to purify water. Moringa seed oil also has potential for use as a biofuel. Biofuel is a renewable and eco-friendly alternative to conventional non-renewable fossil petrodiesel fuel. Azad et al. 51), reviewed the prospect of Moringa oleifera seed oil as a sustainable biodiesel fuel and concluded that MO is one of the prospective industrial crops for biodiesel production in Austria.

Chemical constituents of moringa oleifera

The chemical constituents of moringa oleifera stems, leaves, flowers, pods and seeds have been analyzed for the presence of bioactive compounds, demonstrating the predominance of secondary metabolites, such as phenolic acids, gallic acid, ellagic acid, chlorogenic acid, ferulic acid, glucosinolates, flavonoids, quercetin, vanillin and kaempferol, which have nutritional, pharmaceutical and/or antimicrobial properties 52). However, the amount of these metabolites in moringa oleifera extracts varies according to geographic location, soil, sun exposure and climatic conditions 53). Moreover, the method and solvents used for extraction can modify the content of the compounds obtained from the plant, mainly phenols and flavonoids 54).

Many phytoconstituents of moringa oleifera have been isolated and studied, as shown in Table 5. The main phytochemicals obtained from the plant include:

  • tannins, saponins, alkaloids, flavonoids, phenols and glycosides from leaves 55);
  • tannins, steroids, flavonoids, alkaloids, glycosides, quercetin and terpenoids from flowers 56);
  • gallic acid, catechins, epicatechin, ferulic acid, vanillin, caffeic acid, protocatecuic acid, cinnamic acid, phytosterol, quercetin, glycosides and phenols from seeds 57);
  • procyanidins, aurantiamide acetate, 3-dibenzylurea, quercetin glycoside, rhamnoglucoside quercetin, and chlorogenic acid from roots; and procyanidin, sterols, triterpenoids, glycosides, tannins, alkaloids, β-sitosterol and octacosanoic acid from stem bark 58).

Table 5. Phytoconstituents of different parts of Moringa oleifera

Plant partPhytoconstituentsGroup
Seedsβ-sitosterol Phytosterol
Leaves, stem and roots4-α-l-rhamnopyranosyloxy-benzylglucosinolateGlucosinolate
Leaves, seeds and roots4-(α-l-rhamnosyloxy-benzyl) isothiocyanateGlucosinolate
Leaves4-O-glucopyranosyl-caffeoyl quinic acidCaffeoylquinic acid
SeedsGlycerol-1-(9-octadecanote)Glycoside
Seeds, leaves, stem and rootsKaempferolFlavonoid
Leaves and seedsNiazimicinGlycoside
Leaves and seedsNiazininGlycoside
Leaves(α-l-rhamnosyloxy)benzyl) carbamateGlucosinolate
Seeds, leaves, stem and rootsQuercetinFlavonoid
Roots and flowersPterygosperminGlycoside
[Source 59)]

Moringa oleifera side effects

No adverse effects were reported in any of the human studies that have been conducted to date 60). Furthermore, various preparations have been and continued to be used around the world as foods and as medicinals without the report of ill effects. Several animal studies have specifically assessed the potential toxicity of various preparations on moringa oleifera.

The safety of an aqueous leaf extract given orally to rats at doses of 400, 800, 1600, and 2000 mg/kg body weight was examined 61). The treatment was either an acute single dose or given daily for 21 days except the highest dose. Various parameters were assessed including blood cell counts and serum enzyme levels. The authors concluded that consumption of M. oleifera leaves at doses of up to 2000 mg/kg were safe. A dose-dependent decrease in body weights of the rats occurred over the 21 days of the study.

Asare et al. 62) examined the potential toxicity of an aqueous leaf extract of moringa oleifera in several different experimental systems. In one set of experiments, human peripheral blood mononuclear cells were exposed in vitro to graded doses of the extract and cytotoxicity was assessed. Cytotoxicity occurred at 20 mg/kg, a concentration not achievable by oral ingestion. In another set of experiments, rats were given 1000 and 3000 mg/kg of the extract, and the animals were assessed for up to 14 days. The M. oleifera leaf extract was shown to be genotoxic based on blood cell analysis at the 3000 mg/kg dose, a dose that greatly exceeds commonly used doses. A dose of 1000 mg/kg was deemed safe and did not produce genotoxicity when given to rats, a dose still in excess of commonly used doses.

Ambi et al. 63) divided 24 rats into four groups and fed varying amounts of M. oleifera powdered leaves mixed with standard livestock feed (25%, 50%, 75%, and control) for 93 days. Total amount of M. oleifera leaves consumed was not quantified. Following the experimental period, some organs of the treated animals had observable microscopic lesions with the 75% group developed necrosis of hepatic cells, splenic blood vessels, and neuronal glial cells. The control animals had no observable microscopic lesions in all organs examined. No photomicrographs of any tissues were provided. The amounts of leaves consumed, although not quantified by the authors, greatly exceeded doses that would be typically used in either rats or humans. For example, if the rats consumed an average of 15–20 g of chow per day, even at the low dose of 25% of the chow, the daily dose would be approximately 15–20 g of leaves per kilogram for an adult rat, which would equate to 195–260 g for an 80-kg human.

The toxicity of an aqueous extract of Moringa oleifera leaves has also been evaluated in mice 64). In an acute study, mice were administered the extract at up to 6400 mg/kg orally and 1500 mg/kg intraperitoneally. In a subchronic study, mice received 250, 500, and 1500 mg/kg orally for 60 days. The lethal dose of 50% LD50 was estimated to be 1585 mg/kg. No significant effects were observed with respect to hematological or biochemical parameters or sperm quality. A high degree of safety was observed on oral administration.

The toxicological effects associated with consumption of 50, 100, 200, or 400 mg/kg of methanol extract of M. oleifera for 8 weeks was performed in 30 rats 65). The extract was a 30:1 concentration. All experimental animals that received M. oleifera had a significant increase in body weight in a dose-dependent manner, contrary to what is observed with an aqueous extract 66). Rats that received Moringa oleifera at 200 and 400 mg/kg showed a significant increase in serum alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, and creatinine. It should be noted that the extract was prepared with methanol and not water. The 30:1 concentration of the methanol extract at a dose of 400 mg/kg would be equivalent to 12 g of leaves per kilogram, a very unrealistic dose. The composition of the extract was not reported, and it is not clear how the composition of the methanol extract relates to the composition of aqueous extracts, which are commonly used.

Bakre et al. 67) determined that the lethal dose of 50% of an orally administered ethanol extract of Moringa oleifera leaves in mice was greater than 6.4 g/kg. The dietary effects of Moringa oleifera leaves as a dietary supplement for liver function were performed by Zvinorova et al. 68). Thirty-two weanling rats were randomly assigned to diets of normal rat feed fed at 20% and 14% of body mass, or Moringa-supplemented feeds fed at 20% and 14% of body mass for 5 weeks. Moringa supplementation did not affect blood metabolite concentrations, liver glycogen, or lipid storage.

The potential toxicological effects of a single oral dose of 5000 mg/kg of an aqueous Moringa oleifera extract as well as oral doses of up to 1000 mg/kg of the same extract for 14 days on rats were examined 69). The authors noted that no overt adverse reactions were observed at these doses, and no histopathological findings were found. Small but statistically significant dose-dependent increases in several liver enzymes were observed. A dose of 1000 mg/kg in a rat is equivalent to over 30 times a typical 400 mg dose of an aqueous extract in an 80-kg human.

The genotoxicity of an aqueous Moringa oleifera seed extract was assessed using three separate assay systems including the Ames assay 70). The seed extract was not genotoxic without metabolic activation, and did not pose a risk to human health. The effect of a hexane extract of Moringa oleifera leaves on reproductive organs of male rats was examined 71). The extract was given orally at doses of 17, 170, and 1700 mg/kg body weight for 21 days. A dose-dependent increase in testis and epididymis weights, in seminiferous tubule diameter, and epididymal epithelium thickness without change in plasma gonadotropin levels was observed. The authors concluded that the changes were associated with an increase in spermatogenesis.

For the sake of completeness, several studies involving Moringa oleifera seeds and roots will be described, although the results cannot be directly compared or equated with studies involving leaves. Cytotoxicity of an aqueous extract of Moringa oleifera seeds was evaluated by Araújo et al. 72). Following 14 days of the extract administration (500 and 2000 mg/kg) in mice, no signs of systemic toxicity were observed, and all the animals survived. There were no changes in organ indices between treatment and control groups. Small but insignificant changes were observed in erythrocytes, platelets, hemoglobin, and hematocrit. All values remained within the normal range.

A methanol extract of seeds of Moringa oleifera were screened phytochemically for chemical components and used for acute and subacute toxicity studies in rats 73). The phytochemical screening revealed the presence of saponins, tannins, terpenes, alkaloids, flavonoids, carbohydrates, and cardiac glycosides but the absence of anthraquinones. Although signs of acute toxicity were observed at an extract dose of 4000 mg/kg, mortality was recorded at 5000 mg/kg. No adverse effects were observed at concentrations lower than 3000 mg/kg. The authors concluded that methanol extracts of seeds of Moringa oleifera are safe for nutritional use.

Paul and Didia 74) investigated the effect(s) of methanol extract of Moringa oleifera root on the histo-architecture of the liver and kidney of 24 guinea-pigs. Experimental conditions included daily intraperitoneal injections of the root extract at doses of 3.6, 4.6, and 7.0 mg/kg, and control for 3 weeks. Histological sections of all treated groups had ballooning degeneration of the liver, suggesting time-dependent hepatotoxicity rather than a dose-dependent response. Examination of the kidneys, demonstrated mild tubular damage and interstitial inflammation in the 4.6 mg/kg group, while the 7.0 mg/kg group had infiltration of the interstitium by inflammatory cells and amorphous eosinophilic materials. No information was provided regarding extract composition or degree of concentration. The results of this study cannot be compared or equated with studies involving aqueous extracts of leaves. This study involved a methanol extract of roots, which was given intraperitoneally and not orally.

In summary, based on human, animal, and in vitro studies, and the extrapolation of results from animal studies to humans, various preparations of Moringa oleifera leaves including aqueous extracts appear to be safe at the doses and in the amounts commonly utilized 75). Various animal studies have assessed the general safety of extracts. And no adverse effects were reported in a human study conducted with whole leaf powder at up to a single dose of 50 g or in a study using 8 g per day dose for 40 days. A typical dose of an aqueous extract in rats is approximately 300 mg/kg, which would be equivalent to a dose of about 3.9 g in an 80-kg (176 lb) human. No human studies involving aqueous extracts have been reported, and little information is available regarding the percentage of the powdered whole leaf material that is typically solubilized by extraction with water or alcohol. If 10% of the whole leaf powder is solubilized by aqueous extraction, a 4 g dose of the whole leaf powder would equate to 400 mg of an extract 76).

Moringa health benefits

Moringa oleifera has long been used in traditional medicine. The phytochemicals of Moringa oleifera have shown antidyslipidemic, anthelmintic, antihyperglycemic, anti-inflammatory, antimicrobial, antioxidant, antiproliferative, anti-ulcer, antiurolithiatic, and hepatoprotective properties (mostly in test tube and animal stduies – see Table 5). Potent antiproliferative and apoptotic properties of the Moringa oleifera leaf extract, rich in quercetin and kaempferol phenolics compounds, have been demonstrated using the human tumor (KB) cell line model. The Moringa oleifera leaf extract has shown significant morphological changes and decreased cell viability, with increased internucleosomal DNA fragmentation and reactive oxygen species generation in the KB cells 77).

Chronic hyperglycemia is an indicator of diabetes mellitus (type-2 diabetes mellitus), similarly, chronic dyslipidemia is a potential risk factor for cardiovascular disease (coronary heart disease). While data collected from human subjects are limited, several trials demonstrating potential benefits for treating hyperglycemia and dyslipidemia primarily in people with type 2 diabetes have been published.

In a single dose study with six type 2 diabetic subjects, the feeding of 50 g of a M. oleifera leaf powder with a standard meal on a one-time basis decreased blood glucose levels by 21% 78). The authors concluded that the reduced blood glucose response to Moringa oleifera was not due to alterations in insulin secretion.

Kumari 79) treated individuals with type-2 diabetes with 8 g of powdered Moringa oleifera leaf in a tablet form per day for 40 days. A total of 46 subjects were involved in the study. At the end of the study, fasting blood glucose and postprandial blood glucose were 28% and 26% lower, respectively, in the treated subjects. Furthermore, total cholesterol, triglycerides, low density lipoprotein (LDL)-cholesterol, and very low density lipoprotein-cholesterol were 14%, 14%, 29%, and 15% lower relative to the control group.

Nambiar et al. 80) examined the anti-dyslipidemic effects of Moringa oleifera in 35 type 2 diabetic subjects. The treated group received 4.6 g of a leaf powder in a tablet form daily for 50 days. Compared with the control group, the treated subjects experienced a 1.6% decrease in total plasma cholesterol and a 6.3% increase in HDL. Comparing this study with the previous studies suggests that higher doses may be more effective.

Ghiridhari et al. 81) conducted a study in which 60 type 2 diabetic subjects were given two Moringa oleifera leaf powder tablets per day or placebo for up to 3 months. Unfortunately, the weight of the tablets and therefore the actual dose of the leaf powder were not given. After 3 months, postprandial blood glucose had decreased by 29% relative to the control group, while hemoglobin A1C, an index of glycosylation related to blood glucose levels, decreased by 0.4%.

In another human study, Kushwaha et al. 82) studied 30 postmenopausal women who were supplemented daily with 7 g of Moringa oleifera leaf powder for a period of 3 months. A control group also consisted of 30 postmenopausal women. The data revealed significant increases in serum glutathione peroxidase (18.0%), superoxide dismutase (10.4%), and ascorbic acid (44.4%), with decreases in malondialdehyde (16.3%; lipid peroxidation), markers of antioxidant properties. In addition, a significant decrease in fasting blood glucose levels (13.5%) as well as an increase in hemoglobin (17.5%) was observed. No adverse effects were reported.

In summary, the previous human studies indicate that whole leaf powders of Moringa oleifera given orally exhibit significant anti-hyperglycemic, anti-dyslipidemic, and antioxidant effects in human subjects without production of adverse effects 83). None of these studies involved the use of leaf extracts.

Table 6. Biological activities of different extracts of Moringa oleifera

ExtractActivitiesReferences
Water extract of foliageHypolipidemic and antiatheroscleroticChumark et al. 84)
Aqueous extract of foliage, fruits, and seedsOxidative DNA damage protectiveSingh et al. 85)
Hydroalcoholic extract of foliageAntiperoxidative and cardioprotectiveNandave et al. 86)
Water extract of foliageAntiproliferation and apoptosis cancer cellsSreelatha et al. 87)
Hydroethanolic extracts of foliage, fruits, and seedsHepatoprotectiveUjah et al. 88)
Methanol and ethanol extract of foliageInhibition of differentiation of colon cancer cellsLea et al. 89)
Aqueous extract of foliageDown-regulation of nuclear factor-kappaBBerkovich et al. 90)
Ethanol extract of foliageUpregulation of TNF-αAkanni et al. 91)
Ethanol extract of foliageHypolipidaemic in Hypercholesterolemic RatsAtsukwei et al. 92)
Methanol extract of foliageAntioxidant, anti-inflammatory and antinociceptiveAdedapo et al. 93)
Acetone extracts of foliageAntimicrobial and antioxidantRatshilivha et al. 94)
Methanol, ethyl acetate, and aqueous extracts of seedsAntimicrobialEmmanuel et al. 95)
Isothiocyanate-rich extract of foliageWeight gain, insulin resistance and hepatic gluconeogenesisWaterman et al. 96)
Ethanol extract of foliageAntihyperglycemic and hypolipidemicIrfan et al. 97)
Aqueous extract of foliageImmunity against Herpes
Simplex Virus Type 1 (HSV-1)
Kurokawa et al. 98)
[Source 99)]

Summary

Moringa oleifera, has nutritional with potential pharmacological and antioxidant properties, thus having several medicinal applications. Moringa oleifera is used in the tropics as a food source to overcome malnutrition, especially in children and infants 100), 101). Among the several nutrients found in different parts of Moringa oleifera, proteins are the most abundant, accounting for approximately 25% of dry weight 102), and at least 19 amino acids have been identified in this plant. Furthermore, Moringa oleifera also contains several minerals and vitamins. Lipids are abundant in seeds, mainly stearic acid, saturated palmitic acid and oleic acid, representing about 30% of dry weight. The lipidic compounds linolenic acid and palmitic acid are the main constituents of Moringa oleifera leaves. In addition, the high nutritional content found in dried leaves is an indicator of the usefulness of the plant as a food resource.

The studies on therapeutic potential of Moringa oleifera leaves in hyperglycemia and dyslipidemia provide compelling, albeit very preliminary, experimental evidence. No report contradicting this evidence was found in the scientific literature. However, a common weakness of all the human studies reviewed herein was the fact that none was randomized and double-blind, raising the possibilities of bias in the allocation of patients to control and experimental groups. Further exploration of the potentials and the eventual use of Moringa oleifera therapy in humans will require that the content in fibers, phytosterols as well in antioxidant and anti-inflammatory activities be evaluated and documented in Moringa oleifera formulations destined to the treatment of atherosclerosis or diabetes.

In conclusion, based on the available experimental evidence, Moringa oleifera leaf powder holds some therapeutic potential for chronic hyperglycemia and hyperlipidemia. However, before it is advocated in any formulation for the treatment of these metabolic disorders in humans, state-of-the art clinical studies must be conducted to establish the consistency of its medicinal efficacy and the safest modalities of its administration 103).

References   [ + ]

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