Wild and domesticated Moringa oleifera differ in taste, glucosinolate composition, and antioxidant potential, but not myrosinase activity or protein content

Comparative Metabolomic Analysis of Moringa oleifera Leaves of Different Geographical Origins and Their Antioxidant Effects on C2C12 Myotubes

Moringa oleifera is widely grown throughout the tropics and increasingly used for its therapeutic and nutraceutical properties. These properties are attributed to potent antioxidant and metabolism regulators, including glucosinolates/isothiocyanates as well as flavonoids, polyphenols, and phenolic acids. Research to date largely consists of geographically limited studies that only examine material available locally. These practices make it unclear as to whether moringa samples from one area are superior to another, which would require identifying superior variants and distributing them globally. Alternatively, the finding that globally cultivated moringa material is essentially functionally equivalent means that users can easily sample material available locally. We brought together accessions of Moringa oleifera from four continents and nine countries and grew them together in a common garden. We performed a metabolomic analysis of leaf extracts (MOLE) using an LC-MSMS ZenoTOF 7600 mass spectrometry system. The antioxidant capacity of leaf samples evaluated using the Total Antioxidant Capacity assay did not show any significant difference between extracts. MOLE samples were then tested for their antioxidant activity on C2C12 myotubes challenged with an oxidative insult. Hydrogen peroxide (H2O2) was added to the myotubes after pretreatment with different extracts. H2O2 exposure caused an increase in cell death that was diminished in all samples pretreated with moringa extracts. Our results show that Moringa oleifera leaf extract is effective in reducing the damaging effect of H2O2 in C2C12 myotubes irrespective of geographical origin. These results are encouraging because they suggest that the use of moringa for its therapeutic benefits can proceed without the need for the lengthy and complex global exchange of materials between regions.

Nutritional value and therapeutic potential of Moringa oleifera: a short overview of current research

A member of the Moringaceae family, Moringa Oleifera Lam is a perennial deciduous tropical tree known as the 'Miracle Tree' for its medicinal and nutritional benefits. Food and nutrition are crucial aspects of the development and maintenance of healthy health. Moringa oleifera is a multi-purpose herbal bush that is used as both human food and a medical alternative all over the world. Various parts of the tree are used to treat chronic diseases such as hypertension, heart disease, inflammation, oxidative stress, diabetes, and cancer. Moringa is an excellent source of essential nutrients and has been found to have a significant impact on improving nutritional deficiencies in populations with limited access to food. Moringa oleifera contains essential amino acids, carotenoids, minerals, fats, carbohydrates, proteins, phytochemicals, vitamins, and fibre. Moringa offers nutritional and economic advantages, medicinal and therapeutic uses, and future biological potential for human well-being.

Development of Moringa oleifera as functional food targeting NRF2 signaling: antioxidant and anti-inflammatory activity in experimental model systems

Pharmacological activation of nuclear factor erythroid 2 related factor 2 (NRF2) provides protection against several environmental diseases by inhibiting oxidative and inflammatory injury. Besides high in protein and minerals, Moringa oleifera leaves contain several bioactive compounds, predominantly isothiocyanate moringin and polyphenols, which are potent inducers of NRF2. Hence, M. oleifera leaves represent a valuable food source that could be developed as a functional food for targeting NRF2 signaling. In the current study, we have developed a palatable M. oleifera leaf preparation (henceforth referred as ME-D) that showed reproducibly a high potential to activate NRF2. Treatment of BEAS-2B cells with ME-D significantly increased NRF2-regulated antioxidant genes (NQO1, HMOX1) and total GSH levels. In the presence of brusatol (a NRF2 inhibitor), ME-D-induced increase in NQO1 expression was significantly diminished. Pre-treatment of cells with ME-D mitigated reactive oxygen species, lipid peroxidation and cytotoxicity induced by pro-oxidants. Furthermore, ME-D pre-treatment markedly inhibited nitric oxide production, secretory IL-6 and TNF-α levels, and transcriptional expression of Nos2, Il-6, and Tnf-α in macrophages exposed to lipopolysaccharide. Biochemical profiling by LC-HRMS revealed glucomoringin, moringin, and several polyphenols in ME-D. Oral administration of ME-D significantly increased NRF2-regulated antioxidant genes in the small intestine, liver, and lungs. Lastly, prophylactic administration of ME-D significantly mitigated lung inflammation in mice exposed to particulate matter for 3-days or 3-months. In conclusion, we have developed a pharmacologically active standardized palatable preparation of M. oleifera leaves as a functional food to activate NRF2 signaling, which can be consumed as a beverage (hot soup) or freeze-dried powder for reducing the risk from environmental respiratory disease.

Supplementation of cooked broccoli with exogenous moringa myrosinase enhanced isothiocyanate formation

Brassica vegetables, especially broccoli, have health benefits such as anticancer activity, which are attributed to isothiocyanate (ITC), products of glucosinolate hydrolysis. This study aimed to explore the effect of cooking time and addition of exogenous myrosinase (MYR) from moringa seeds on the yield of ITCs. The results showed that raw broccoli produced a significantly high amount of ITCs, which decreased by almost 40% after microwaving the broccoli for 1 min. Introducing exogenous MYR by adding ground moringa seeds to cooked broccoli caused a notable increase in ITC of 38%. At pH 4.0-6.0, MYR showed optimal activity, and the thermal stability of MYR from moringa seeds was better than that from broccoli. The kinetic parameters indicated that MYR from moringa seeds had a higher affinity to sinigrin than that from broccoli seeds. This study was novel in reporting that adding ground moringa seeds to cooked broccoli enhanced ITC formation.

The Future of Moringa Foods: A Food Chemistry Perspective

The tree Moringa oleifera Lam. provides its leaves, pods, flowers and seeds for human nutrition. The chemical profile of all these Moringa products varies substantially, not only among the different parts of the plants used. Cultivating, processing as well as storage conditions chiefly determine the contents of nutrients and anti-nutritive constituents. Anti-nutrients, e.g., phytic acid or tannins, are present in notable amounts and may affect micronutrient bioavailability. Although Moringa oleifera products have been promoted for several health benefits and are discussed as an alternative treatment in various diseases, risk assessment studies evaluating contamination levels are scarce. Recent investigations have demonstrated alarming contents of heavy metals, polycyclic aromatic hydrocarbons and mycotoxins in Moringa oleifera products, indicating the need for a comprehensive risk assessment and contingent legal regulation of these products. In this mini review, we briefly outline pivotal, food chemistry and nutrition related data on Moringa preparations in order to stimulate in-depth research to close the presented knowledge gaps.

The Metabolism of Glucosinolates by Gut Microbiota

Glucosinolates (GLS) and their derivatives are secondary plant metabolites abundant in Brassicaceae. Due to the enzymatic reaction between GLS and myrosinase enzyme, characteristic compounds with a pungent taste are formed, used by plants to defend themselves against insect herbivores. These GLS derivatives have an important impact on human health, including anti-inflammation and anti-cancer effects. However, GLS derivatives' formation needs previous enzymatic reactions catalyzed by myrosinase enzyme. Many of the brassica-based foods are processed at a high temperature that inactivates enzymes, hindering its bioavailability. In the last decade, several studies showed that the human gut microbiome can provide myrosinase activity that potentially can raise the beneficial effects of consumption of vegetables rich in GLS. The variability of the human gut microbiome (HGM) in human populations and the diverse intake of GLS through the diet may lead to greater variability of the real dose of pro-healthy compounds absorbed by the human body. The exploitation of the genetic and biochemical potential of HGM and correct ecological studies of both isolated strains and mixed population are of great interest. This review focuses on the most recent advances in this field.

Effect of Solid-State Fermentation on Nutritional Quality of Leaf Flour of the Drumstick Tree (Moringa oleifera Lam.)

The drumstick tree is a fast-growing multipurpose tree with a large biomass and high nutritional value. However, it has rarely been exploited as a protein source. This study investigated solid-state fermentation induced by Aspergillus niger, Candida utilis and Bacillus subtilis to obtain high-quality protein feed from drumstick leaf flour. The results showed that fermentation induced significant changes in the nutritional composition of drumstick leaf flour. The concentrations of crude protein, small peptides and amino acids increased significantly after fermentation. The protein profile was also affected by the fermentation process. Macromolecular proteins in drumstick leaf flour were degraded, whereas other high molecular weight proteins were increased. However, the concentrations of crude fat, fiber, total sugar and reducing sugar were decreased, as were the anti-nutritional factors tannins, phytic acid and glucosinolates. After 24 h fermentation, the concentrations of total phenolics and flavonoids were increased. The antioxidant capacity was also significantly enhanced.

Therapeutic Potentials of Antiviral Plants Used in Traditional African Medicine With COVID-19 in Focus: A Nigerian Perspective

The coronavirus disease 2019 (COVID-19) pandemic is caused by an infectious novel strain of coronavirus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which was earlier referred to as 2019-nCoV. The respiratory disease is the most consequential global public health crisis of the 21st century whose level of negative impact increasingly experienced globally has not been recorded since World War II. Up till now, there has been no specific globally authorized antiviral drug, vaccines, supplement or herbal remedy available for the treatment of this lethal disease except preventive measures, supportive care and non-specific treatment options adopted in different countries via divergent approaches to halt the pandemic. However, many of these interventions have been documented to show some level of success particularly the Traditional Chinese Medicine while there is paucity of well reported studies on the impact of the widely embraced Traditional African Medicines (TAM) adopted so far for the prevention, management and treatment of COVID-19. We carried out a detailed review of publicly available data, information and claims on the potentials of indigenous plants used in Sub-Saharan Africa as antiviral remedies with potentials for the prevention and management of COVID-19. In this review, we have provided a holistic report on evidence-based antiviral and promising anti-SARS-CoV-2 properties of African medicinal plants based on in silico evidence, in vitro assays and in vivo experiments alongside the available data on their mechanistic pharmacology. In addition, we have unveiled knowledge gaps, provided an update on the effort of African Scientific community toward demystifying the dreadful SARS-CoV-2 micro-enemy of man and have documented popular anti-COVID-19 herbal claims emanating from the continent for the management of COVID-19 while the risk potentials of herb-drug interaction of antiviral phytomedicines when used in combination with orthodox drugs have also been highlighted. This review exercise may lend enough credence to the potential value of African medicinal plants as possible leads in anti-COVID-19 drug discovery through research and development.

Effects of Adding Moringa oleifera Leaves Powder on the Nutritional Properties, Lipid Oxidation and Microbial Growth in Ground Beef during Cold Storage

The utilisation of Moringa oleifera leaves powder (MOLP) to improve the nutritional properties and inhibit lipid oxidation and the proliferation of microorganisms in ground beef during cold storage was examined. The effects of 0.2, 0.4, 0.6, and 0.8% MOLP on the nutritional properties (proximate composition, total phenolic and total flavonoid content), thiobarbituric acid reactive substances (TBARS), microbial composition, physicochemical characteristics (pH value, colour attributes, and cooking properties), and sensory analysis of ground beef were investigated. The findings showed that ash, protein, polyphenolic compounds, pH, colour, and microbial growth increased significantly, while moisture, fat content, and TBARS decreased significantly, with an increase in the concentration of MOLP during cold storage. Moderate levels (0.2 and 0.4%) of MOLP did not affect the sensory attributes of stored ground beef. Evidently, MOLP can be utilised as a natural preservative in ground beef to improve the nutritional value and inhibit lipid oxidation.

Glucosinolates and Isothiocyanates from Moringa oleifera: Chemical and Biological Approaches

Alternative therapies, such as phytotherapy, are considered to improve the health status of people with chronic non-communicable diseases (CNCDs). In this regard, Moringa oleifera is currently being studied for its nutritional value and its total phenolic content. Besides phenolic compounds, the phytochemical composition is also of great interest. This composition is characterized by the presence of glucosinolates and isothiocyanates. Isothiocyanates formed by the biotransformation of Moringa glucosinolates contain an additional sugar in their chemical structure, which provides stability to these bioactive compounds over other isothiocyanates found in other crops. Both glucosinolates and isothiocyanates have been described as beneficial for the prevention and improvement of some chronic diseases. The content of glucosinolates in Moringa tissues can be enhanced by certain harvesting methods which in turn alters their final yield after extraction. This review aims to highlight certain features of glucosinolates and isothiocyanates from M. oleifera, such as their chemical structure, functionality, and main extraction and harvesting methods. Some of their health-promoting effects will also be addressed.

Solid state fermentation of Moringa oleifera leaf meal by mixed strains for the protein enrichment and the improvement of nutritional value

Moringa oleifera Lam. (MO) is a fast-growing multi-purpose deciduous tree with high biomass and nutritional value. However, the presence of antinutritional factors, poor palatability, and indigestibility of Moringa oleifera leaf meal (MOLM) restrict its application to animal feed. This study aimed to obtain high-quality protein feeds via solid-state fermentation (SSF) of MOLM. The process conditions for increasing the true protein (TP) content using Aspergillus niger, Candida utilis and Bacillus subtilis co-cultures were optimized, and the chemical composition of MOLM was compared before and after fermentation. The results of this study showed that the highest TP content could be obtained through mixed-strain culture of A. niger, C. utilis and B. subtilis at a ratio of 1:1:2. The MOLM was inoculated with A. niger, followed by C. utilis and B. subtilis 24 h later. The optimized co-culture parameters were as follows: total inoculation size, 24%; temperature, 32 °C; fermentation time, 6.5 days; and initial water content, 60%. The maximum TP yield was 28.37%. Notably, in the fermented MOLM (FMOLM), the content of nutrients such as crude protein (CP), small peptides, and total amino acids (AAs) were significantly increased relative to unfermented MOLM, whereas the contents of crude fiber (CF), tannin, and phytic acid were significantly decreased. MOLM analysis using scanning electron microscopy (SEM) revealed that SSF disrupted the surface structure of MOLM, and sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) indicated that macromolecular proteins were degraded. The in vitro protein digestibility (IVPD) of FMOLM was also improved significantly. Our findings suggest that multi-strain fermentation with A. niger, C. utilis and B. subtilis improves the nutritional quality of MOLM, rendering it a viable functional feedstuff for use in livestock industries in the future.

Evolutionary analysis of the Moringa oleifera genome reveals a recent burst of plastid to nucleus gene duplications

It is necessary to identify suitable alternative crops to ensure the nutritional demands of a growing global population. The genome of Moringa oleifera, a fast-growing drought-tolerant orphan crop with highly valuable agronomical, nutritional and pharmaceutical properties, has recently been reported. We model here gene family evolution in Moringa as compared with ten other flowering plant species. Despite the reduced number of genes in the compact Moringa genome, 101 gene families, grouping 957 genes, were found as significantly expanded. Expanded families were highly enriched for chloroplastidic and photosynthetic functions. Indeed, almost half of the genes belonging to Moringa expanded families grouped with their Arabidopsis thaliana plastid encoded orthologs. Microsynteny analysis together with modeling the distribution of synonymous substitutions rates, supported most plastid duplicated genes originated recently through a burst of simultaneous insertions of large regions of plastid DNA into the nuclear genome. These, together with abundant short insertions of plastid DNA, contributed to the occurrence of massive amounts of plastid DNA in the Moringa nuclear genome, representing 4.71%, the largest reported so far. Our study provides key genetic resources for future breeding programs and highlights the potential of plastid DNA to impact the structure and function of nuclear genes and genomes.

Glucosinolates: Natural Occurrence, Biosynthesis, Accessibility, Isolation, Structures, and Biological Activities

Glucosinolates (GSLs) are secondary plant metabolites abundantly found in plant order Brassicales. GSLs are constituted by an S-β-d-glucopyrano unit anomerically connected to O-sulfated (Z)-thiohydroximate moiety. The side-chain of the O-sulfate thiohydroximate moiety, which is derived from a different amino acid, contributes to the diversity of natural GSL, with more than 130 structures identified and validated to this day. Both the structural diversity of GSL and their biological implication in plants have been biochemically studied. Although chemical syntheses of GSL have been devised to give access to these secondary metabolites, direct extraction from biomass remains the conventional method to isolate natural GSL. While intact GSLs are biologically inactive, various products, including isothiocyanates, nitriles, epithionitriles, and cyanides obtained through their hydrolysis of GSLs, exhibit many different biological activities, among which several therapeutic benefits have been suggested. This article reviews natural occurrence, accessibility via chemical, synthetic biochemical pathways of GSL, and the current methodology of extraction, purification, and characterization. Structural information, including the most recent classification of GSL, and their stability and storage conditions will also be discussed. The biological perspective will also be explored to demonstrate the importance of these prominent metabolites.

HPLC analysis, cytotoxicity, and safety study of Moringa oleifera Lam. (wild type) leaf extract

The study was planned to evaluate toxicity of M. oleifera leaf methanol extract in Wistar rats, cytotoxic potential and chemically characterize it. Acute toxicity study revealed no mortality at 2,000 mg/kg dose. In subchronic toxicity, 150, 300, and 600 mg/kg extract were administered in both sexes for 90 days. A decrease in body weight, cholesterol, and low-density lipoproteins, as well as an increase in the platelet count were observed. The histology of heart, lung, and kidney was normal. The oxidative stress biomarkers were normal in the liver tissue. In vitro cytotoxicity assay revealed that IC50 of the plant extract was more than 1,000 µg/ml. FTIR explored various functional groups and HPLC analysis indicated the presence of kaempferol and quercetin in the plant extract. These results showed that the plant extract might be safe up to 2,000 mg/kg single dose. The long term use of the plant extract was mostly devoid of major system toxicities. PRACTICAL APPLICATIONS: M. oleifera is a multipurpose tree. It is a cruciferous plant that has nutritional as well as medicinal properties. It is exhibited a multitude of nutraceutical or pharmacological properties such as anti-inflammatory, lipid-lowering, anticancer, hypoglycemic, and antihypertensive activities. It is widely used by local inhabitants for their health, food, agriculture, and cosmetic purposes. Among other plant parts, its leaves are mostly used as a functional food because of abundant proteins, β-carotene, polyphenol, vitamin C, and vitamin E. The current study was designed to validate its safety in acute and long term use. The data of this study suggested that the plant can be safely used as a nutraceutical as well as a nutritional food.

The glucosinolates and their bioactive derivatives in Brassica: a review on classification, biosynthesis and content in plant tissues, fate during and after processing, effect on the human organism and interaction with the gut microbiota

The present study is a systematic review of the scientific literature reporting content, composition and biosynthesis of glucosinolates (GLS), and their derivative compounds in Brassica family. An amended classification of brassica species, varieties and their GLS content, organized for the different plant organs and in uniformed concentration measure unit, is here reported for the first time in a harmonized and comparative manner. In the last years, the studies carried out on the effect of processing on vegetables and the potential benefits for human health has increased rapidly and consistently the knowledge on the topic. Therefore, there was the need for an updated revision of the scientific literature of pre- and post-harvest modifications of GLS content, along with the role of gut microbiota in influencing their bioavailability once they are ingested. After analyzing and standardizing over 100 articles and the related data, the highest GLS content in Brassica, was declared in B. nigra (L.) W. D. J. Koch (201.95 ± 53.36 µmol g^-1), followed by B. oleracea Alboglabra group (180.9 ± 70.3 µmol g^-1). The authors also conclude that food processing can influence significantly the final content of GLS, considering the most popular methods: boiling, blanching, steaming, the latter can be considered as the most favorable to preserve highest level of GLS and their deriviatives. Therefore, a mild-processing strategic approach for GLS or their derivatives in food is recommended, in order to minimize the loss of actual bioactive impact. Finally, the human gut microbiota is influenced by Brassica-rich diet and can contribute in certain conditions to the increasing of GLS bioavailability but further studies are needed to assess the actual role of microbiomes in the bioavailability of healthy glucosinolate derivatives.

Glucosinolate structural diversity, identification, chemical synthesis and metabolism in plants

The glucosinolates (GSLs) is a well-defined group of plant metabolites characterized by having an S-β-d-glucopyrano unit anomerically connected to an O-sulfated (Z)-thiohydroximate function. After enzymatic hydrolysis, the sulfated aglucone can undergo rearrangement to an isothiocyanate, or form a nitrile or other products. The number of GSLs known from plants, satisfactorily characterized by modern spectroscopic methods (NMR and MS) by mid-2018, is 88. In addition, a group of partially characterized structures with highly variable evidence counts for approximately a further 49. This means that the total number of characterized GSLs from plants is somewhere between 88 and 137. The diversity of GSLs in plants is critically reviewed here, resulting in significant discrepancies with previous reviews. In general, the well-characterized GSLs show resemblance to C-skeletons of the amino acids Ala, Val, Leu, Trp, Ile, Phe/Tyr and Met, or to homologs of Ile, Phe/Tyr or Met. Insufficiently characterized, still hypothetic GSLs include straight-chain alkyl GSLs and chain-elongated GSLs derived from Leu. Additional reports (since 2011) of insufficiently characterized GSLs are reviewed. Usually the crucial missing information is correctly interpreted NMR, which is the most effective tool for GSL identification. Hence, modern use of NMR for GSL identification is also reviewed and exemplified. Apart from isolation, GSLs may be obtained by organic synthesis, allowing isotopically labeled GSLs and any kind of side chain. Enzymatic turnover of GSLs in plants depends on a considerable number of enzymes and other protein factors and furthermore depends on GSL structure. Identification of GSLs must be presented transparently and live up to standard requirements in natural product chemistry. Unfortunately, many recent reports fail in these respects, including reports based on chromatography hyphenated to MS. In particular, the possibility of isomers and isobaric structures is frequently ignored. Recent reports are re-evaluated and interpreted as evidence of the existence of "isoGSLs", i.e. non-GSL isomers of GSLs in plants. For GSL analysis, also with MS-detection, we stress the importance of using authentic standards.

Correction to: Moringa oleifera leaf extracts attenuate Complete Freund's adjuvant-induced arthritis in Wistar rats via modulation of inflammatory and oxidative stress biomarkers

In our article entitled "Moringa rivae leaf extracts attenuate Complete Freund's adjuvant-induced arthritis in Wistar rats via modulation of inflammatory and oxidative stress biomarkers", we described the anti-arthritic effects of the plant leaves from Pakistan that we referred to as Moringa rivae (Saleem et al. 2019). Unfortunately, the identity of the plant material was incorrect. In fact, the plant leaves under study were later identified as belonging to wild type Moringa oleifera Lam. rather than Moringa rivae Chiov.

Dynamics of Bacterial Community and Fermentation Quality during Ensiling of Wilted and Unwilted Moringa oleifera Leaf Silage with or without Lactic Acid Bacterial Inoculants

Moringa oleifera leaf is a high-quality feed source for livestock and is increasingly used all over the world. Ensiling might be an effective method for preservation of the leaves. In the practice of silage making, lactic acid bacterial inoculants and wilting are commonly used to improve nutrition preservation. Monitoring the changes in a bacterial community during fermentation gives an insight into understanding and improving the ensiling process. Our results suggest that wilting and lactic acid bacterial inoculants had an influence on the bacterial community and fermentation process of M. oleifera leaf silage. Wilting showed positive effects on silage fermentation by decreasing the abundance of Enterobacter spp., while LF and LL improved the fermentation quality by inhibiting Enterobacter spp. and enhancing Lactobacillus spp. Both LF and LL accelerated the ensiling process from cocci (like Lactococcus, Enterococcus, and Leuconostoc spp.) to lactobacilli.

To investigate the effects of wilting and lactic acid bacterial inoculants on the fermentation quality and bacterial community of Moringa oleifera leaf silage, fresh and wilted M. oleifera leaves were ensiled with or without Lactobacillus farciminis LF or Lactococcus lactis LL for 1, 7, 14, 30, and 60 days. The results showed that wilting, inoculants, and their interaction exerted significant (P < 0.05) effects on the fermentation characteristics covering dry matter loss, pH value, lactic acid bacterial number, the ratio of lactic acid to acetic acid, and the relative abundances of bacteria, like for species of Lactobacillus, Lactococcus, Pediococcus, Enterococcus, Leuconostoc, and Enterobacter. Both LF and LL improved the fermentation quality of wilted and unwilted M. oleifera leaf silage by accelerating lactic acid production and pH decline, decreasing dry matter loss, and inhibiting yeast and coliform bacterial growth through the whole fermentation process. During ensiling, the abundances of Lactococcus, Enterococcus, and Leuconostoc spp. increased from day 1 to day 7 and then declined sharply from day 7 to day 14. Members of these genera and Enterobacter were inhibited, whereas Lactobacillus spp. were enhanced by these two lactic acid bacterial inoculants. The relative abundances of Enterobacter, Enterococcus, and Pediococcus spp. in inoculated silages were relatively low during the whole ensiling process. A lower abundance of Enterobacter spp. was observed in wilted silages than in unwilted silages. In summary, wilting and lactic acid bacterial inoculants had an influence on bacterial community and the fermentation process; LF and LL improved the fermentation quality of wilted and unwilted M. oleifera leaf silage.

IMPORTANCEMoringa oleifera leaf is a high-quality feed source for livestock and is increasingly used all over the world. Ensiling might be an effective method for preservation of the leaves. In the practice of silage making, lactic acid bacterial inoculants and wilting are commonly used to improve nutrition preservation. Monitoring the changes in a bacterial community during fermentation gives an insight into understanding and improving the ensiling process. Our results suggest that wilting and lactic acid bacterial inoculants had an influence on the bacterial community and fermentation process of M. oleifera leaf silage. Wilting showed positive effects on silage fermentation by decreasing the abundance of Enterobacter spp., while LF and LL improved the fermentation quality by inhibiting Enterobacter spp. and enhancing Lactobacillus spp. Both LF and LL accelerated the ensiling process from cocci (like Lactococcus, Enterococcus, and Leuconostoc spp.) to lactobacilli.

A Strategy to Deliver Precise Oral Doses of the Glucosinolates or Isothiocyanates from Moringa oleifera Leaves for Use in Clinical Studies

The tropical tree Moringa oleifera produces high yields of protein-rich leaf biomass, is widely used as a food source, contains an abundance of phytochemicals, and thus has great potential for chronic disease prevention and perhaps, treatment. We have developed and characterized standardized ways of preparing aqueous “teas” from moringa leaves to deliver precisely calibrated levels of phytochemicals for use in clinical trials. These phytochemicals, especially the glucosinolate glucomoringin and the isothiocyanate moringin, produced from it following hydrolysis by the enzyme myrosinase, provide potent anti-inflammatory and cytoprotective indirect antioxidant activity. The taste of both hot and cold teas is palatable without the need for flavor masking. These teas can be easily and reproducibly prepared in underserved tropical regions of the world where moringa is cultivated. Isothiocyanate yield from a cold extraction was rapid and essentially complete after 30 min and its anti-inflammatory potential is comparable to that of equimolar purified moringin. A preparation similar to this may be safe to consume with respect to its bacterial titer even after 48 h without refrigeration. Thus, facile delivery of moringa tea to both adults and children for clinical evaluation of their effects on such conditions as autism, diabetes, and hypertension, is now possible.

Effect of Moringa oleifera Leaf Powder on Postprandial Blood Glucose Response: In Vivo Study on Saharawi People Living in Refugee Camps

The hypoglycemic effect in humans of Moringa oleifera (MO) leaf powder has, to date, been poorly investigated. We assessed the chemical composition of MO leaf powder produced at Saharawi refugee camps, its in vitro ability to inhibit α-amylase activity, and its sensory acceptability in food. We then evaluated its effect on postprandial glucose response by randomly administering, on 2 different days, a traditional meal supplemented with 20 g of MO leaf powder (MOR20), or not (control meal, CNT), to 17 Saharawi diabetics and 10 healthy subjects. Capillary glycaemia was measured immediately before the meal and then at 30 min intervals for 3 h. In the diabetic subjects the postprandial glucose response peaked earlier with MOR20 compared to CNT and with lower increments at 90, 120, and 150 min. The mean glycemic meal response with MOR20 was lower than with CNT. The healthy subjects showed no differences. Thus, MO leaf powder could be a hypoglycemic herbal drug. However, given the poor taste acceptability of the 20 g MO meal, lower doses should be evaluated. Moreover, the hypoglycemic effects of MO leaf powder should also be demonstrated by trials evaluating its long-term effects on glycaemia.

The Diversity of Chemoprotective Glucosinolates in Moringaceae (Moringa spp.)

Glucosinolates (GS) are metabolized to isothiocyanates that may enhance human healthspan by protecting against a variety of chronic diseases. Moringa oleifera, the drumstick tree, produces unique GS but little is known about GS variation within M. oleifera, and even less in the 12 other Moringa species, some of which are very rare. We assess leaf, seed, stem, and leaf gland exudate GS content of 12 of the 13 known Moringa species. We describe 2 previously unidentified GS as major components of 6 species, reporting on the presence of simple alkyl GS in 4 species, which are dominant in M. longituba. We document potent chemoprotective potential in 11 of 12 species, and measure the cytoprotective activity of 6 purified GS in several cell lines. Some of the unique GS rank with the most powerful known inducers of the phase 2 cytoprotective response. Although extracts of most species induced a robust phase 2 cytoprotective response in cultured cells, one was very low (M. longituba), and by far the highest was M. arborea, a very rare and poorly known species. Our results underscore the importance of Moringa as a chemoprotective resource and the need to survey and conserve its interspecific diversity.