Isolation of ellagic acid from the aqueous extract of the roots of Decalepis hamiltonii: Antioxidant activity and cytoprotective effect

Preparation, In Vivo and Molecular Docking Study of Nano-Emulsion Obtained From the Isolated Phytoconstituents of Symplocos racemosa for Mitigating Depression

Depression is a prevalent, chronic, and debilitating disorder characterized by high treatment resistance. Symplocos racemosa, containing phenols and triterpenoids, acts as an antidepressant by elevating brain monoamine levels. This study aimed to enhance the targeted delivery of S. racemosa via nano-emulsion and improve its therapeutic efficacy against depression. In addition, it sought to elucidate the molecular mechanisms underlying its effects through molecular docking studies. S. racemosa bark was extracted using methanol and ethyl acetate, yielding six phytoconstituents (ellagic acid, betulinic acid, acetyl oleanolic acid, salireposide, oleanolic acid, and symlocoside) through column chromatography. Molecular docking against MAO-A was performed to confirm significant binding affinity. A chitosan-loaded herbal nano-emulsion containing these phytoconstituents was formulated for enhanced brain delivery tested using animal studies using forced swim test (FST) and actophotometer models. Docking studies confirmed that all the components exhibit a good binding toward MAO-A, comparable to standard moclobemide, and among all salireposide has the most significant and better binding affinity, higher than moclobemide. Nano-emulsion, at both dosages, reduced the immobility time in the FST and increased the locomotor activity in the actophotometer of depressed mice. Nano-emulsion of isolated phytoconstituents from S. racemosa exhibited synergistic effects, effectively managing depression by inhibiting MAO-A.

Ellagic Acid: A Green Multi-Target Weapon That Reduces Oxidative Stress and Inflammation to Prevent and Improve the Condition of Alzheimer's Disease

Oxidative stress (OS), generated by the overrun of reactive species of oxygen and nitrogen (RONS), is the key cause of several human diseases. With inflammation, OS is responsible for the onset and development of clinical signs and the pathological hallmarks of Alzheimer's disease (AD). AD is a multifactorial chronic neurodegenerative syndrome indicated by a form of progressive dementia associated with aging. While one-target drugs only soften its symptoms while generating drug resistance, multi-target polyphenols from fruits and vegetables, such as ellagitannins (ETs), ellagic acid (EA), and urolithins (UROs), having potent antioxidant and radical scavenging effects capable of counteracting OS, could be new green options to treat human degenerative diseases, thus representing hopeful alternatives and/or adjuvants to one-target drugs to ameliorate AD. Unfortunately, in vivo ETs are not absorbed, while providing mainly ellagic acid (EA), which, due to its trivial water-solubility and first-pass effect, metabolizes in the intestine to yield UROs, or irreversible binding to cellular DNA and proteins, which have very low bioavailability, thus failing as a therapeutic in vivo. Currently, only UROs have confirmed the beneficial effect demonstrated in vitro by reaching tissues to the extent necessary for therapeutic outcomes. Unfortunately, upon the administration of food rich in ETs or ETs and EA, URO formation is affected by extreme interindividual variability that renders them unreliable as novel clinically usable drugs. Significant attention has therefore been paid specifically to multitarget EA, which is incessantly investigated as such or nanotechnologically manipulated to be a potential "lead compound" with protective action toward AD. An overview of the multi-factorial and multi-target aspects that characterize AD and polyphenol activity, respectively, as well as the traditional and/or innovative clinical treatments available to treat AD, constitutes the opening of this work. Upon focus on the pathophysiology of OS and on EA's chemical features and mechanisms leading to its antioxidant activity, an all-around updated analysis of the current EA-rich foods and EA involvement in the field of AD is provided. The possible clinical usage of EA to treat AD is discussed, reporting results of its applications in vitro, in vivo, and during clinical trials. A critical view of the need for more extensive use of the most rapid diagnostic methods to detect AD from its early symptoms is also included in this work.

Current trends in natural products for the treatment and management of dementia: Computational to clinical studies

The number of preclinical and clinical studies evaluating natural products-based management of dementia has gradually increased, with an exponential rise in 2020 and 2021. Keeping this in mind, we examined current trends from 2016 to 2021 in order to assess the growth potential of natural products in the treatment of dementia. Publicly available literature was collected from various databases like PubMed and Google Scholar. Oxidative stress-related targets, NF-κB pathway, anti-tau aggregation, anti-AChE, and A-β aggregation were found to be common targets and pathways. A retrospective analysis of 33 antidementia natural compounds identified 125 sustainable resources distributed among 65 families, 39 orders, and 7 classes. We found that families such as Berberidaceae, Zingiberaceae, and Fabaceae, as well as orders such as Lamiales, Sapindales, and Myrtales, appear to be important and should be researched further for antidementia compounds. Moreover, some natural products, such as quercetin, curcumin, icariside II, berberine, and resveratrol, have a wide range of applications. Clinical studies and patents support the importance of dietary supplements and natural products, which we will also discuss. Finally, we conclude with the broad scope, future challenges, and opportunities for field researchers.

Potentiation of paraquat toxicity by inhibition of the antioxidant defenses and protective effect of the natural antioxidant, 4-hydroxyisopthalic acid in Drosophila melanogaster

Exposure to pesticides such as paraquat (PQ) is known to induce oxidative stress-mediated damage, which is implicated in neurodegenerative diseases. The antioxidant enzymes are part of the endogenous defense mechanisms capable of protecting against oxidative damage, and down-regulation of these enzymes results in elevated oxidative stress. In this study, we have evaluated the protective action of 4-hydroxyisophthalic acid (DHA-I), a novel bioactive molecule from the roots of D. hamiltonii, against PQ toxicity and demonstrated the protective role of endogenous antioxidant enzymes under the condition of oxidative stress using Drosophila model. The activity of the major antioxidant enzymes, superoxide dismutase 1 (SOD1) and catalase, was suppressed either by RNAi-mediated post transcriptional gene silencing or chemical inhibition. With the decreased in vivo activity of either SOD1 or catalase, Drosophila exhibited hypersensitivity to PQ toxicity, demonstrating the essential role of antioxidant enzymes in the mechanism of defense against PQ-induced oxidative stress. Dietary supplementation of DHA-I increased the resistance of Drosophila depleted in either SOD1 or catalase to PQ toxicity. Enhanced survival of flies against PQ toxicity indicates the protective role of DHA-I against oxidative stress-mediated damage under the condition of compromised antioxidant defenses.

In vitro-derived plants grown from low nitrate medium produced quality tubers in Decalepis hamiltonii Wight & Arn

In the present study, influence of nitrate concentration on in vitro rooting and its ex vitro hardened tubers were investigated in D. hamiltonii. In vitro multiple shoots established on the MS medium were used as explants for this study and concentration of indole-3-butyric acid (1.23 µM) required for root initiation was determined. The effect of different nitrate concentrations in MS medium for in vitro rooting was investigated and positive (¼ and ½ strength) influence was observed on 14 days inoculation. The in vitro rooted plants (IVP) showed 80% survival upon hardening and exhibited similar growth pattern to seedling plants. The 1-year grew ex vitro hardened plants were evaluated for their tuber quality with reference to their yield and flavor metabolite 2-hydroxy-4-methoxy benzaldehyde (2H4MB) content. The IVP grown from ¼ nitrate strength media produced 155 ± 4.85 g FW of tuber biomass which is observed to be higher than full nitrate strength IVP (112 ± 2.52 g) which are grown under similar conditions in the greenhouse. The flavor metabolite content, total phenolics, total flavonoids, and antioxidant potential of these IVP tubers were evaluated. Upregulation of flavor biosynthetic pathway genes DhPAL, DhC4H and DhCoMT were observed in tubers of potted plants that developed from low nitrate strength culture media. In this study, superiority of tissue cultured plants was evident, wherein in vitro plants developed in low nitrate strength medium and acclimatized could produce a higher yield in tuber biomass and maintain relative content of flavor compounds in this endangered plant.

Neuroprotective Potential of Ellagic Acid: A Critical Review

Ellagic acid (EA) is a dietary polyphenol present in various fruits, vegetables, herbs, and nuts. It exists either independently or as part of complex structures, such as ellagitannins, which release EA and several other metabolites including urolithins following absorption. During the past few decades, EA has drawn considerable attention because of its vast range of biological activities as well as its numerous molecular targets. Several studies have reported that the oxidative stress-lowering potential of EA accounts for its broad-spectrum pharmacological attributes. At the biochemical level, several mechanisms have also been associated with its therapeutic action, including its efficacy in normalizing lipid metabolism and lipidemic profile, regulating proinflammatory mediators, such as IL-6, IL-1β, and TNF-α, upregulating nuclear factor erythroid 2-related factor 2 and inhibiting NF-κB action. EA exerts appreciable neuroprotective activity by its free radical-scavenging action, iron chelation, initiation of several cell signaling pathways, and alleviation of mitochondrial dysfunction. Numerous in vivo studies have also explored the neuroprotective attribute of EA against various neurotoxins in animal models. Despite the increasing number of publications with experimental evidence, a critical analysis of available literature to understand the full neuroprotective potential of EA has not been performed. The present review provides up-to-date, comprehensive, and critical information regarding the natural sources of EA, its bioavailability, metabolism, neuroprotective activities, and underlying mechanisms of action in order to encourage further studies to define the clinical usefulness of EA for the management of neurological disorders.

Anti-sickling activities of two isolated compounds from the root of Combretum racemosum P. beauv. (Combretaceae)

ETHNOPHARMACOLOGICAL RELEVANCE

Evaluation of plants such as Combretum racemosum with claimed traditional use in the management of sickle cell anaemia in Nigeria and other parts of West Africa could serve as a useful research strategy in the search for potential anti-sickling drugs and templates.

AIM OF THE STUDY

This study aimed at evaluating the antisickling potential of C. racemosum by activity-guided purification and isolation of its active constituents.

MATERIALS AND METHODS

Crude methanol extract of the root of C. racemosum and the fractions obtained by partitioning with chloroform, ethyl acetate, and aqueous were investigated for anti-sickling activity against sodium metabisulphite induced sickling of sickle cell haemoglobin (HbSS). Repeated chromatographic separations were conducted on the most active chloroform fraction to purify and isolate bioactive compounds for further tests for anti-sickling activity. The characterization of the isolated compounds was done by mass spectrometry (FD⁺MS) and nuclear magnetic resonance (¹HNMR) spectroscopy.

RESULTS

The chloroform fraction (FA) (% sickled erythrocyte ranged from 3.0 to 34.1) exhibited better anti-sickling activity than aqueous (% sickled erythrocyte ranged from 38.9 to 51.5) as well as the crude methanol (% sickled erythrocyte ranged from 19.1 to 30.4). Hence, the phytochemical investigation was focused on the chloroform fraction, which led to the identification of two ellagic acid derivatives (3,3',4'-tri-O-methyl ellagic acid (A) and 3,3'-di-O- methyl ellagic acid (B). The two isolated compounds possessed good, comparable anti-sickling activities with compound A exhibiting a slightly better in vitro activity.

CONCLUSION

This paper reports for the first time anti-sickling principles from C. racemosum and therefore, provided some justification for the ethnomedicinal use of the plant in the management of sickle cell disease.

Cytotoxic Compounds from the Stem Bark of Two subsp. of Bersama abyssinica

Three new bufadienolides, namely, paulliniogenin A (1), paulliniogenin B (2), and 16β-formyloxybersamagenin 1,3,5-orthoacetate (3), together with two known bufadienolides and six known phenolic substances, were isolated from the stem bark of Bersama abyssinica subsp. abyssinica and B. abyssinica subsp. paullinioides. The structures of the compounds were elucidated based on their NMR and HRMS data analyses. The relative configurations were defined by single-crystal X-ray crystallography and NOESY correlations. Cytotoxicity against the L929 and KB3.1 cancer cell lines of the isolated compounds was investigated using an MTT assay. Paulliniogenin A (1) and 16β-hydroxybersamagenin-1,3,5-orthoacetate (4) showed cytotoxicity against the KB3.1 cell line with IC₅₀ values of 1.4 ± 0.77 and 1.6 ± 0.81 μM, respectively. Moreover, paulliniogenin A (1) and paulliniogenin B (2) demonstrated weak activity against Staphylococcus aureus.

Pectin-Based Formulations for Controlled Release of an Ellagic Acid Salt with High Solubility Profile in Physiological Media

Among bioactive phytochemicals, ellagic acid (EA) is one of the most controversial because its high antioxidant and cancer-preventing effects are strongly inhibited by low gastrointestinal absorption and rapid excretion. Strategies toward an increase of solubility in water and bioavailability, while preserving its structural integrity and warranting its controlled release at the physiological targets, are therefore largely pursued. In this work, EA lysine salt at 1:4 molar ratio (EALYS), exhibiting a more than 400 times increase of water solubility with respect to literature reports, was incorporated at 10% in low methoxylated (LM) and high methoxylated (HM) pectin films. The release of EA in PBS at pH 7.4 from both film preparations was comparable and reached 15% of the loaded compound over 2 h. Under simulated gastric conditions, release of EA from HM and LM pectin films was minimal at gastric pH, whereas higher concentrations—up to 300 μM, corresponding to ca. 50% of the overall content—were obtained in the case of the HM pectin film after 2 h incubation at the slightly alkaline pH of small intestine environment, with the enzyme and bile salt components enhancing the release. EALYS pectin films showed a good prebiotic activity as evaluated by determination of short chain fatty acids (SCFAs) levels following microbial fermentation, with a low but significant increase of the effects produced by the pectins themselves. Overall, these results highlight pectin films loaded with EALYS salt as a promising formulation to improve administration and controlled release of the compound.

Unravelling the Antibacterial Activity of Terminalia sericea Root Bark through a Metabolomic Approach

Terminalia sericea Burch. ex. DC. (Combretaceae) is a popular remedy for the treatment of infectious diseases. It is widely prescribed by traditional healers and sold at informal markets and may be a good candidate for commercialisation. For this to be realised, a thorough phytochemical and bioactivity profile is required to identify constituents that may be associated with the antibacterial activity and hence the quality of raw materials and consumer products. The aim of this study was to explore the phytochemistry and identify the antibacterial constituents of T. sericea root bark, using a metabolomic approach. The chemical profiles and antibacterial activities of 42 root bark samples collected from three districts in the Limpopo Province, South Africa, were evaluated. Dichloromethane:methanol (1:1) extracts were analysed using ultraperformance liquid chromatography (UPLC)-mass spectrometry (MS), and chemometric models were constructed from the aligned data. The extracts were tested against Bacillus cereus (ATCC 11778), Staphylococcus epidermidis (ATCC 12223), Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 8739), Klebsiella pneumoniae (ATCC 13883), Pseudomonas aeruginosa (ATCC 27853), Shigella sonnei (ATCC 9292) and Salmonella typhimurium (ATCC 14028), using the minimum inhibition microdilution assay. Nine compounds; sericic acid, sericoside, resveratrol-3-O-β-rutinoside, ellagic acid, flavogallonic acid dilactone, methyl-flavogallonate, quercetin-3-(2′′-galloylrhamnoside), resveratrol-3-(6′′-galloyl)-O-β-d-glucopyranoside and arjunetin, were isolated from the root bark. All the compounds, with the exception of sericic acid, sericoside and resveratrol-3-O-β-rutinoside, were isolated for the first time from the root bark of T. sericea. Chemometric analysis revealed clustering that was not population specific, and the presence of three groupings within the samples, characterised by sericic acid, sericoside and an unidentified compound (m/z 682/4.66 min), respectively. The crude extracts from different populations displayed varied antibacterial activities against S. typhimurium (minimum inhibitory concentrations (MICs) 0.25–1.0 mg/mL), but similar activity towards Bacillus cereus (1.0 mg/mL). Several compounds present in the root bark were highly active towards all or most of the pathogens tested, but this activity was not reflected by the chemical profiles of extracts prepared from the individual samples. Among the pure compounds tested, only flavogallonic acid dilactone and methyl-flavogallonate exhibited broad-spectrum activity. A biochemometric analysis indicated that there was no consistent association between the levels of phytochemicals and the activity of the active or non-active extracts. Although it was deduced that the major constituents of T. sericea root bark contributed to the chemotypic variation, further investigation of the interactions of compounds present in the root bark may provide antibacterial efficacies not evident when examining compounds singularly. The data reported herein will provide information that is fundamentally important for the development of quality control protocols.

The Potential Use of Plant Natural Products and Plant Extracts with Antioxidant Properties for the Prevention/Treatment of Neurodegenerative Diseases: In Vitro, In Vivo and Clinical Trials

Neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease and Huntington's disease, present a major health issue and financial burden for health care systems around the world. The impact of these diseases will further increase over the next decades due to increasing life expectancies. No cure is currently available for the treatment of these conditions; only drugs, which merely alleviate the symptoms. Oxidative stress has long been associated with neurodegeneration, whether as a cause or as part of the downstream results caused by other factors. Thus, the use of antioxidants to counter cellular oxidative stress within the nervous system has been suggested as a potential treatment option for neurological disorders. Over the last decade, significant research has focused on the potential use of natural antioxidants to target oxidative stress. However, clinical trial results have lacked success for the treatment of patients with neurological disorders. The knowledge that natural extracts show other positive molecular activities in addition to antioxidant activity, however, has led to further research of natural extracts for their potential use as prevention or treatment/management of neurodegenerative diseases. This review will cover several in vitro and in vivo research studies, as well as clinical trials, and highlight the potential of natural antioxidants.

Escalation of liver malfunctioning: A step toward Herbal Awareness

ETHNOPHARMACOLOGICAL RELEVANCE

About 2-5% of the world's population is suffering from liver toxicity including Pakistan with the second highest rate of hepatitis prevalence. Liver is a vital body organ which not only performs metabolic activities but also aids in detoxification, storage and digestion of food. Now a day's malnutrition, alcohol consumption and drug addiction are major causes of liver diseases throughout the world. In fact, there is no possible outcome to compensate liver malfunction for long term, and transplantation of liver is the only option left after the irretrievable injury of hepatic function. Subsequently, natural based therapeutic approaches are in the process of scrupulous testing as strong hepatoprotective mediator. In this regard plants are well thought hepatoprotective agents having multiple active components. In this review, based on species' pharmacology and safety we have compiled some plants which show strong hepatoprotective activity, main phytoconstituents with biological activities and few commercially used herbal formulations.

MATERIALS AND METHODS

Ethnopharmacological information was gathered by an extensive literature survey like WHO monographs on selected herbal medicinal plants (Vol 1-Vol 4); Principles and Practice of Phytotherapy, Mills S and Bone K, Churchill Livingstone, London, UK; Herbal Drugs and Phytopharmaceuticals, Wichtl M Medpharm Press, Stuttgart 3rd edn; Pharmacology and Applications of Chinese Materia Medica Vols 1 and 2, Chang H-M and But P P-H World Scientific, Singapore; British Herbal Compendium Vol. 2, Bradley P British Herbal Medicine Association, Bournemouth, UK; ESCOP Monographs 2nd edn. Thieme, Stuttgart, Germany; as well as by using electronic databases such as Pubchem, Chemspider, http://www.herbal-ahp.org; http://www.ahpa.org; http://whqlibdoc.who.int/publications/2003/9241546271.pdf; http://www.escop.com, Pubmed, HubMed and Scopus.

RESULTS

Data for more about 29 plants have been accomplished for their bioactive constituent(s), biological activities and medicinal uses. Some of the plants have been identified as strong hepato-modulator. Such knowledge about traditional medicinal plants can be globally applied for safe and evidence based use in pharmacological applications.

CONCLUSION

With the rise in liver risks a meek struggle has been made to draw attention toward herbal therapy. Hepatoprotective constituents of said plants are expressed with chemical structures. However, for certain plants active constituents are not still isolated/purified but overall plant extract was found effective in providing protection against hepatic injury. As a future perspective, there is need to purify plant active constituents for ethnomedical rationale.

Antiaflatoxigenic and Antimicrobial Activities of Schiff Bases of 2-Hydroxy-4-methoxybenzaldehyde, Cinnamaldehyde, and Similar Aldehydes

2-Hydroxy-4-methoxybenzaldehyde (HMBA) is a nontoxic phenolic flavor from dietary source Decalipus hamiltonii and Hemidesmus indicus. HMBA is an excellent antimicrobial agent with additional antiaflatoxigenic potency. On the other hand, cinnamaldehyde from cinnamon is a widely employed flavor with significant antiaflatoxigenic activity. We have attempted the enhancement of antiaflatoxigenic and antimicrobial properties of HMBA, cinnamaldehyde, and similar molecules via Schiff base formation accomplished from condensation reaction with amino sugar (d-glucamine). HMBA derived Schiff bases exhibited commendable antiaflatoxigenic activity at the concentration 0.1 mg/mL resulting in 9.6 ± 1.9% growth of Aspergillus flavus and subsequent 91.4 ± 3.9% reduction of aflatoxin B₁ with respect to control.

Effect of different polyphenol sources on the efficiency of ellagic acid release by Aspergillus niger

Fungal hydrolysis of ellagitannins produces hexahydroxydiphenic acid, which is considered an intermediate molecule in ellagic acid release. Ellagic acid has important and desirable beneficial health properties. The aim of this work was to identify the effect of different sources of ellagitannins on the efficiency of ellagic acid release by Aspergillus niger. Three strains of A. niger (GH1, PSH and HT4) were assessed for ellagic acid release from different polyphenol sources: cranberry, creosote bush, and pomegranate used as substrate. Polyurethane foam was used as support for solid-state culture in column reactors. Ellagitannase activity was measured for each of the treatments. Ellagic acid was quantified by high performance liquid chromatography. When pomegranate polyphenols were used, a maximum value of ellagic acid (350.21 mg/g) was reached with A. niger HT4 in solid-state culture. The highest amount of ellagitannase (5176.81 U/l) was obtained at 8h of culture when cranberry polyphenols and strain A. niger PSH were used. Results demonstrated the effect of different polyphenol sources and A. niger strains on ellagic acid release. It was observed that the best source for releasing ellagic acid was pomegranate polyphenols and A. niger HT4 strain, which has the ability to degrade these compounds for obtaining a potent bioactive molecule such as ellagic acid.

Attenuation of neuromotor deficits by natural antioxidants of Decalepis hamiltonii in transgenic Drosophila model of Parkinson's disease

Oxidative stress is believed to be a major factor for the onset of Parkinson's disease (PD). In this study, we have investigated oxidative status in transgenic Drosophila model of PD. Our results revealed elevated levels of reactive oxygen species (ROS) and lipid peroxidation (LPO) in A30P and A53T α-synuclein PD model flies compared to control. We have demonstrated for the first time the ameliorating potential of natural antioxidants characterized from the roots of Dh in A30P and A53T α-synuclein PD model flies. Feeding of transgenic flies with aqueous Dh root extract for 21 days significantly improved their climbing ability and circadian rhythm of locomotor activity which was associated with reduction in levels of ROS and LPO and enhancement in the activities of catalase (CAT) and superoxide dismutase (SOD). Dh protected against paraquat (PQ) sensitivity in α-synuclein transgenic flies and delayed the onset of PD-like symptoms which appears to be mediated by suppression of oxidative stress.

Phytochemistry of the carnivorous sundew genus Drosera (Droseraceae) - future perspectives and ethnopharmacological relevance

Species of the carnivorous genus Drosera L. have long been a source of valuable natural products. The various phytochemicals characteristic of these species, particularly 1,4-naphthoquinones and flavonoids, have contributed to the diverse utilization of sundews in traditional medicine systems worldwide. A growing number of studies have sought to investigate the comparative phytochemistry of Drosera species for improved sources of pharmaceutically important compounds. The outcomes of these studies are here collated, with emergent trends discussed in detail. Important factors which affect production of secondary metabolites in plants are critically examined, such as environmental influences and in vitro culture, and recommendations subsequently presented based on this. Explicitly, the current review aims to i) present an updated, comprehensive listing of the phytochemical constituents of the genus (including quantitative data where available), ii) summarize important factors which may influence the production of phytopharmaceuticals in plants, and iii) recommend guidelines for future research based on the above, including improved standardization and quality control. We have also included a section discussing future perspectives of research on Drosera spp. based on three different research lines i) the potential to produce much needed lead compounds for treatment of tuberculosis, ii) the potential role of anthocyanins in nitrogen transport, and iii) research into 'Natural Deep Eutectic' solvents produced by Drosera spp. in the droplets or 'dew' employed to capture insect prey.

Ellagic acid: an unusually versatile protector against oxidative stress

Several aspects related to the antioxidant activity of ellagic acid were investigated using the density functional theory. It was found that this compound is unusually versatile for protecting against the toxic effects caused by oxidative stress. Ellagic acid, in aqueous solution at physiological pH, is able of deactivating a wide variety of free radicals, which is a desirable capability since in biological systems, these species are diverse. Under such conditions, the ellagic acid anion is proposed as the key species for its protective effects. It is predicted to be efficiently and continuously regenerated after scavenging two free radicals per cycle. This is an advantageous and unusual behavior that contributes to increase its antioxidant activity at low concentrations. In addition, the ellagic acid metabolites are also capable of efficiently scavenging a wide variety of free radicals. Accordingly, it is proposed that the ellagic acid efficiency for that purpose is not reduced after being metabolized. On the contrary, it provides continuous protection against oxidative stress through a free radical scavenging cascade. This is an uncommon and beneficial behavior, which makes ellagic acid particularly valuable to that purpose. After deprotonation, ellagic acid is also capable of chelating copper, in a concentration dependent way, decreasing the free radical production. In summary, ellagic acid is proposed to be an efficient multiple-function protector against oxidative stress.

In vitro antiplasmodial activity of some medicinal plants of Burkina Faso

Malaria remains a major public health problem due to the emergence and spread of Plasmodium falciparum drug resistance. There is an urgent need to investigate new sources of antimalarial drugs which are more effective against Plasmodium falciparum. One of the potential sources of antimalarial drugs is traditional medicinal plants. In this work, we studied the in vitro antiplasmodial activity of chloromethylenic, methanolic, and MeOH/H2O (1/1) crude extracts and decoction obtained from eight medicinal plants collected in Burkina Faso and of total alkaloids for five plants. Extracts were evaluated in vitro for efficacy against Plasmodium falciparum strain K1, which is resistant to chloroquine, pyrimethamine and proguanil using the fluorescence-based SYBR Green I assay. The antiproliferative activity on human-derived hepatoma cell line HepG2 and Chinese hamster ovary (CHO) cells was evaluated using the 3-[4,5-dimethylthyazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) test in order to determine the selectivity index. Among the plant extracts tested for in vitro antiplasmodial activity, 16 were considered to be inactive (with IC50 > 10 μg/ml), six showed a moderate activity (5 < IC50 ≤ 10 μg/ml), and six were found to have a good in vitro activity with IC50 value ≤ 5 μg/ml. The highest antiplasmodial activity was found for extracts from: the alkaloid leaf extract and the chloromethylenic extracts of Combretum fragrans (IC50 = 3 μg/ml, IC50 = 5 μg/ml), the total alkaloids and the chloromethylenic leaf extracts of Combretum collinum (IC50 = 4 μg/ml), the MeOH/H2O leaf extract of Terminalia avicennioides (IC50 = 3.5 μg/ml), and the alkaloid leaf extract of Pavetta crassipes (IC50 = 5 μg/ml). Three other extracts showed moderate antiplasmodial activity (5 < IC50 ≤ 10 μg/ml): Terminalia avicennioides and Combretum fragrans methanolic extracts and Acacia kirkii alkaloid leaf extract (IC50 = 6.5, 9 and 10 μg/ml respectively). The Terminalia avicennioides crude MeOH/H2O (80:20 v/v) extract of the leaves was submitted to a successive liquid/liquid extraction with ethylacetate and n-butanol respectively. The extracts were investigated for in vitro antiplasmodial activity and antioxidant properties using DPPH(·), ABTS(+) and FRAP methods. The ethylacetate extract showed the best antiplasmodial activity (7 μg/ml) and the active constituent was isolated as ellagic acid by bioguided fractionation with an IC50 = 0.2 μM on Plasmodium falciparum and SI = 152. Besides, Terminalia avicennioides leaf extract and ellagic acid showed a good antioxidant activity. Our finding confirms the importance of investigating the antimalarial activity of plant species used in traditional medicine. Overall, two plants belonging to the Combretaceae family, Combretum fragrans and Combretum collinum appeared to be the best candidates and will be further investigated for their antiplasmodial properties, in order to isolate the molecules responsible for the antiplasmodial activity.

Prevention of hexachlorocyclohexane-induced neuronal oxidative stress by natural antioxidants

OBJECTIVE

Decalepis hamiltonii roots are traditionally consumed as general vitalizer and used in ayurvedic medicine preparations. We have isolated/characterized potent antioxidants from the aqueous extract of the root of this plant. In this study, we examined the antioxidant potential of the aqueous extract of the roots of D. hamiltonii (DHAE) against hexachlorocyclohexane (HCH)-induced oxidative stress in four major regions of the rat brain.

METHODS

The antioxidant activity of the standardized DHAE with known antioxidant constituents was tested against HCH-induced oxidative stress in the major brain regions of 60-day-old adult male Wistar rats.

RESULTS

Pretreatment of rats with multiple doses of DHAE, 50 and 100 mg/kg body weight (b.w.), for 7 consecutive days significantly prevented the HCH-induced (single dose -500 mg/kg b.w.) increase in lipid peroxidation, reduction in glutathione, and altered antioxidant enzyme activities viz. superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, and glutathione-S-transferase in major rat brain regions viz. cortex, cerebellum, midbrain, and brain stem. DHAE, per se, elevated the antioxidant status of the rat brain.

DISCUSSION

DHAE shows protective action against HCH-induced oxidative stress in rat brain regions. The protective effect of DHAE could be ascribed to the isolated/characterized antioxidant compounds which could be prospective novel nutraceuticals.

Decalepis hamiltonii inhibits tumor progression and metastasis by regulating the inflammatory mediators and nuclear factor κB subunits

Metastasis is an extremely complex process that is a major problem in the management of cancer. In the present study, we had evaluated the antimetastatic activity of DECALEPIS HAMILTONI: using B16F-10 melanoma-induced experimental lung metastasis in a C57BL/6 mice model.

D HAMILTONI

treatment significantly ( : < .01) inhibited lung tumor nodule formation and reduced the lung collagen hydroxyproline, hexosamine, and uronic acid levels. Similarly serum sialic acid and γ-glutamyl transpeptidase levels were also significantly inhibited after

D HAMILTONI

treatment. The levels of proinflammatory cytokines such as tumor necrosis factor α, interleukin (IL)-1β, IL-6, granulocyte monocyte colony-stimulating factor, and IL-2 in the serum of these animals were significantly altered after

D HAMILTONI

treatment. The serum NO level was also found to be significantly decreased after

D HAMILTONI

treatment. This decreased NO level after

D HAMILTONI

treatment was also accompanied by decreased inducible NO synthase and cyclooxygenase-2 expression. The study reveals that

D HAMILTONI

treatment could alter proinflammatory cytokine production and could inhibit the activation and nuclear translocation of p65 and p50 subunits of nuclear factor κB in B16F-10 cells.

Decalepis hamiltonii root extract attenuates the age-related decline in the cognitive function in Drosophila melanogaster

Age-associated accumulation of oxidative damage linked to decline of antioxidant defense mechanism, leads to impairment of cognitive function in many organisms. These damages can pass through generations and affect the cognitive quality of progenies. In Drosophila, classical olfactory conditioning results in the formation of different types of memory. Age-related memory impairment (AMI) causes reduction in middle term memory (MTM) and parental senescence causes decline in short-term memory (STM) of the offspring. We have further examined the neuromodulatory effect of Decalepis hamiltonii (Dh) root extract, which is a cocktail of novel antioxidant molecules, on the biochemical oxidative defenses in relation to cognitive ability of the aged flies and their offspring. There is a strong correlation between the age-related decline in the activity of the antioxidant enzymes and the lower cognitive ability of the aged flies and their offspring. Feeding of aged flies in the diet containing 0.1% Dh, markedly enhances the cognitive ability of both aged flies and their offspring which is associated with enhanced antioxidant defenses as evident for the activity of superoxide dismutase (SOD) and catalase. Our findings, for the first time, show that the antioxidant-rich Dh root extract attenuates the age-related decline in cognitive ability of Drosophila, and also shows ameliorative effect on the memory of the offspring.

Amelioration of cyclophosphamide-induced hepatotoxicity by the root extract of Decalepis hamiltonii in mice

Hepatoprotective potential of the aqueous extract of the roots of Decalepis hamiltonii (DHA) against cyclophosphamide (CP)-induced oxidative stress has been investigated in mice. Administration of CP (25mg/kg b.w., i.p) for 10 days induced hepatic damage as indicated by the serum marker enzymes aspartate and alanine transaminases (AST, ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH). Parallel to these changes CP induced oxidative stress in the liver as evident from the increased lipid peroxidation (LPO), reactive oxygen species (ROS), depletion of glutathione (GSH), and reduced activities of the antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione-S-transferase (GST). Treatment with DHA (50 and 100 mg/kg b.w., po) mitigated the CP-induced oxidative stress. Moreover, expression of genes for the antioxidant enzymes, were down-regulated by CP treatment which was reversed by DHA. Our study shows the DHA protected the liver from toxicity induced by CP and therefore, it could be serve as a safe medicinal supplement during cyclophosphamide chemotherapy.

One new pyrroline compound from Callistemon viminalis (Sol. Ex Gaertner) G.Don Ex Loudon

One new compound: 3,4-dihydro-2-(hydroxymethyl)-4-methyl-2H-pyrrol-2-ol (5) was isolated from the fruits and bark of Callistemon viminalis along with the known compounds lupeol (1), octacosanol (2), β-sitosterol (3), betulin (4), betulinic acid (6), ursolic acid (7), corosolic acid (8), β-sitosterol-3-O-β-D-glucoside (9), methyl gallate (10), gallic acid (11), catechin (12), ellagic acid (13) and 3-O-acetylursolic acid (14) (compound 14 was isolated from the bark and not detected in the fruits). Structures of these compounds were elucidated on the basis of their spectroscopic data (NMR, MS, IR spectra and COSY and HR-MS for 5a). The antioxidant activity of the total extracts, petroleum ether, CH2Cl2 and EtOAc fractions together with the compounds 6, 7, 9, 10, 11, 12 and 13 was comparable with that of the standard antioxidant, ascorbic acid.

Decaleside: a new class of natural insecticide targeting tarsal gustatory sites

Natural sources for novel insecticide molecules hold promise in view of their eco-friendly nature, selectivity, and mammalian safety. Recent progress in understanding the biology of insect olfaction and taste offers new strategies for developing selective pest control agents. We have isolated two natural insecticidal molecules from edible roots of Decalepis hamiltonii named Decalesides I and II, which are novel trisaccharides, highly toxic to household insect pests and stored-product insects. We have experimentally shown that insecticidal activity requires contact with tarsi on the legs but is not toxic orally. The insecticidal activity of molecules is lost by hydrolysis, and various sugars modify toxic response, showing that the insecticidal activity is via gustatory sites on the tarsi. Selective toxicity to insects by virtue of their gustatory site of action and the mammalian safety of the new insecticides is inherent in their chemical structure with 1-4 or 1-1 α linkage that is easily hydrolyzed by digestive enzymes of mammals. Decalesides represent a new chemical class of natural insecticides with a unique mode of action targeting tarsal chemosensory/gustatory system of insects.

Quantitative determination of bioactive 4-hydroxy-α-tetralone, tetralone-4-O-β-D-glucopyranoside and ellagic acid in Ammannia baccifera (Linn.) by reversed-phase high-performance liquid chromatography

Ammannia baccifera is an important component of various Chinese herbal formulations for which a rapid, simple, sensitive, gradient and reproducible reversed-phase high-performance liquid chromatographic method has been developed for the quantitative estimation of its bioactive constituents, 4-hydroxy-α-tetralone (4H), tetralone-4-O-β-D-glucopyranoside (T4) and ellagic acid (EA). The chromatographic separation of samples was performed on a Chromatopak Peerless C18 (250 × 4.6 mm i.d., 5 µm) column by gradient elution with 0.1% trifluoroacetic acid in water and methanol at a flow rate of 0.6 mL/min, a column temperature at 25°C and ultraviolet detection at λ 254 nm. The limit of detection (LOD) and limit of quantification (LOQ) were 1.51 and 5.06 µg/mL for EA, 0.70 and 2.33 µg/mL for T4 and 0.22 and 0.73 µg/mL for 4H, respectively. Good results were achieved with respect to linearity (r(2) > 0.999), repeatability (relative standard deviation ≤ 1.73%) and recovery (99.06-100.76%). The method was validated for linearity, accuracy, repeatability, LOQ and LOD. The method is simple, accurate and precise and was successfully applied to the analysis of these three analytes in five different leaf and root samples of A. baccifera; the method may be recommended for routine quality control analysis of various Chinese herbal formulations containing A. baccifera.

2,4,8-trihydroxybicyclo [3.2.1]octan-3-one scavenges free radicals and protects against xenobiotic-induced cytotoxicity

Currently, there is a great deal of interest in the study of natural compounds with free-radical-scavenging activity because of their potential role in maintaining human health and preventing diseases. In this paper, we report the antioxidant and cytoprotective properties of 2,4,8-trihydroxybicyclo [3.2.1]octan-3-one (TBO) isolated from the aqueous extract of Decalepis hamiltonii roots. Our results show that TBO is a potent scavenger of superoxide (O(2)·-), hydroxyl (·OH), nitric oxide (·NO) and lipid peroxide (LOO·) - physiologically relevant free radicals with IC(50) values in nmolar (42-281) range. TBO also exhibited concentration-dependent secondary antioxidant activities such as reducing power, metal-chelating activity and inhibition of protein carbonylation. Further, TBO at nmolar concentration prevented CuSO(4)-induced human LDL oxidation. Apart from the in vitro free-radical-scavenging activity, TBO demonstrated cytoprotective activity in primary hepatocytes and Ehrlich ascites tumour (EAT) cells against oxidative-stress-inducing xenobiotics. The mechanism of cytoprotective action involved maintaining the intracellular glutathione (GSH), scavenging of reactive oxygen species (ROS) and inhibiting lipid peroxidation (LPO). Based on the results, it is suggested that TBO is a novel bioactive molecule with implications in both prevention and amelioration of diseases involving oxidative stress as well as in the general well-being.

14-aminotetradecanoic acid exhibits antioxidant activity and ameliorates xenobiotics-induced cytotoxicity

Natural compounds with free-radical scavenging activity have potential role in maintaining human health and preventing diseases. In this study, we report the antioxidant and cytoprotective properties of 14-aminotetradecanoic acid (ATDA) isolated from the Decalepis hamiltonii roots. ATDA is a potent scavenger of superoxide (O(2) (•-)), hydroxyl ((•)OH), nitric oxide ((•)NO), and lipid peroxide (LOO(•)) physiologically relevant free radicals with IC(50) values in nM (36-323) range. ATDA also exhibits concentration-dependent secondary antioxidant activities like reducing power, metal-chelating activity, and inhibition of protein carbonylation. Further, ATDA at nM concentration prevented CuSO(4)-induced human LDL oxidation. ATDA demonstrated cytoprotective activity in primary hepatocytes and Ehrlich ascites tumor cells against oxidative stress inducing xenobiotics apart from the in vitro free-radical scavenging activity. The mechanism of cytoprotective action involved maintaining the intracellular glutathione, scavenging of reactive oxygen species, and inhibition of lipid peroxidation. It is suggested that ATDA is a novel bioactive molecule with potential health implications.

Antioxidant activities and phenolic compounds of date plum persimmon ( Diospyros lotus L.) fruits

In the present study, phenolic compounds are extracted from the date plum persimmon fruits using water, methanol and acetone as solvents. Antioxidant activities of the phenolic extracts are measured using four different tests, namely, DPPH, hydroxyl radical scavenging activities, chelating and reducing power assays. All the extracts show dose dependent DPPH radical scavenging activity, reducing and chelating powers and moreover, they are well correlated with the total phenolic and total flavonoid substances, suggesting direct contribution of phenolic compounds to these activities. In further, the extracts are identified and quantified by HPLC-ECD. Results show that gallic acid is the most abundant phenolic compound, with amounts ranging between 45.49and 287.47 μg/g dry sample. Myricetin is the dominant flavonoid in all extracts. Its level varied from 2.75 μg/g dry sample in acetone extract to 5.28 μg/g dry sample in water extract. On the basis of the results obtained, the date plum persimmon fruits phenolic extract is a potential source of natural antioxidants owing to its significant antioxidant activities.

Antioxidant and cytoprotective properties of 2-(hydroxymethyl)-3-methoxybenzaldehyde

Currently there is a great deal of interest in the study of natural compounds with free radical scavenging activity because of their potential role in maintaining human health and preventing diseases. In this paper, we report the antioxidant and cytoprotective properties of 2-(hydroxymethyl)-3-methoxybenzaldehyde (HMMB) isolated from the aqueous extract of Decalepis hamiltonii roots. Our results show that HMMB is a potent scavenger of superoxide (O2(-)), hydroxyl (OH), nitric oxide (NO), and lipid peroxide (LOO) physiologically relevant free radicals with IC50 values in the nmolar (5-214) range. HMMB also exhibited concentration dependent secondary antioxidant activities, such as reducing power, metal chelating activity, and inhibition of protein carbonylation. Further, HMMB at nmolar concentration prevented CuSO4-induced human LDL oxidation. Apart from the in vitro free radical scavenging activity, HMMB demonstrated cytoprotective activity in primary hepatocytes and Ehrlich Ascites Tumour (EAT) cells against oxidative stress inducing xenobiotics. The mechanism of cytoprotective action involved maintaining the intracellular glutathione (GSH), scavenging of reactive oxygen species (ROS), and inhibition of lipid peroxidation (LPO). Based on the results it is suggested that HMMB is a novel bioactive molecule with health implications in both prevention and amelioration of diseases involving oxidative stress, as well as in the general well being.

Insecticidal activity of the root extract of Decalepis hamiltonii against stored-product insect pests and its application in grain protection

Root extracts of Decalepis hamiltonii were tested for insecticidal activity against the stored products pests, Rhyzopertha domonica, Sitophilus oryzae, Stigobium pancieum, Tribolium castaneum and Callosobruchus chinensis, in residual and contact toxicity bioassays. Methanolic extract showed LC50 value of 0.14 mg/cm(2) for all the test species in a filter paper residual bioassay. The extract was effective as a grain protectant for wheat and green gram. Reduction of F1 progeny was observed in treated grain stored for 3-4 months. The extract did not affect the germination of the treated grains. Our results indicate that methanolic extracts of D. hamiltonii has a potential to control stored product pests and could serve as a natural grain protectant.

Anti inflammatory potential of Decalepis hamiltonii (Wight and Arn) as evidenced by down regulation of pro inflammatory cytokines-TNF-alpha and IL-2

ETHNOPHARMACOLOGICAL RELEVANCE

Ancient tribes in the Western Ghats of India use the roots of Decalepis hamiltonii Wight and Arn (Asclepiadaceae) for several medicinal purposes particularly inflammation.

AIM

To investigate whether the pure compounds obtained from the Decalepis hamiltonii have anti inflammatory activity.

MATERIALS AND METHODS

The bioactive lead molecules from the roots of Decalepis hamiltonii were extracted into dichloromethane/methanol and purified by silica gel column chromatography. Structural elucidation of the purified compounds was performed with (1)H and (13)C NMR and mass spectrometry. The in vitro anti inflammatory activity of the pure compounds was studied in mitogen induced peripheral blood mononuclear cells (PBMCs) employing [(3)H] thymidine uptake assay and their effect on cytokine expression by reverse transcriptase polymerase chain reaction (RT-PCR). The inhibition of nuclear factor kappaB (NF-kappaB) activity in the presence of pure compounds was determined in J774 A.1 cells. The cytotoxicity of the compounds was tested using 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay kit.

RESULTS AND DISCUSSION

Lupeol acetate (Compound 1) and (2S)-5,7,4'-trihydroxy flavanone 4'-O-beta-d-glucoside (Compound 2) isolated from Decalepis hamiltonii roots inhibited the proliferation of mitogen induced PBMCs with an IC(50) value of 8 and 0.5mug/ml respectively. MTT assay revealed the compounds to be non-cytotoxic. Though, both the compounds down regulated the synthesis of mRNA of the pro inflammatory cytokines, interleukin-2 (IL-2) and tumour necrosis factor-alpha (TNF-alpha), the anti inflammatory cytokine interleukin-10 (IL-10), was found to be up regulated. NF-kappaB activation in J774 A.1 cells were also inhibited by both the compounds.

CONCLUSION

Lupeol acetate and (2S)-5,7,4'-trihydroxy flavanone 4'-O-beta-d-glucoside isolated from Decalepis hamiltonii roots showed anti inflammatory activities by down regulating TNF-alpha and IL-2 specific mRNA, besides up regulating the synthesis of mRNA of IL-10.

Identification of major phenolic compounds from Nephelium lappaceum L. and their antioxidant activities

Nephelium lappaceum is a tropical fruit whose peel possesses antioxidant properties. Experiments on the isolation and identification of the active constituents were conducted, and on their antioxidant activity using a lipid peroxidation inhibition assay. The methanolic extract of N. lappaceum peels exhibited strong antioxidant properties. Sephadex LH-20 chromatography was utilized in the isolation of each constituent and the antioxidant properties of each was studied. The isolated compounds were identified as ellagic acid (EA) (1), corilagin (2) and geraniin (3). These compounds accounted for 69.3% of methanolic extract, with geraniin (56.8%) as the major component, and exhibited much greater antioxidant activities than BHT in both lipid peroxidation (77-186 fold) and DPPH* (42-87 fold) assays. The results suggest that the isolated ellagitannins, as the principal components of rambutan peels, could be further utilized as both a medicine and in the food industry.

Stereospecificity in the cytotoxic action of hexachlorocyclohexane isomers

Hexachlorocyclohexane (HCH) is a highly recalcitrant organochlorine insecticide known for its chronic toxicity. In spite of many isolated studies a clear mechanism of cytotoxic action of HCH and the structure-toxicity relationship of its isomers is not well understood. We have investigated the toxicity of HCH isomers and its mechanism in Ehrlich Ascites tumor (EAT) cells. Our studies show differential cytotoxicity of HCH isomers (alpha, beta, gamma, and delta), delta isomer being most toxic and beta the least. HCH-induced cell death was associated with induction of reactive oxygen species (ROS) formation, lipid peroxidation (LPO), and depletion of glutathione (GSH). The increase in oxidative stress was linked with increased NAD(P)H oxidase activity. HCH inhibited Na(+),K(+)-ATPase, which could be involved in raising the intracellular calcium and increased Ca(2+),Mg(2+)-ATPase activity. HCH lead to apoptotic as well as necrotic cell death as it was marked by increased caspase-3 activity and lactate dehydrogenase (LDH) leakage, respectively. Based on the results it is concluded that the HCH isomers inflict differential cytotoxicity which was highest by delta and lowest by beta. Further, this study demonstrates for the first time a clear link between Na(+),K(+)-ATPase, i[Ca(2+)] level, and oxidative stress in HCH-induced cytotoxicity.