Mangrove plants as a source of lead compounds for the development of new antiplasmodial drugs from South East coast of India

Antimalarial compounds from the climbing stems of salacia debilis

Salacia debilis Walp., (Celastraceae) is used traditionally in West Africa for the treatment of malaria. However, no scientific reports validating these effects and its active constituents are on record. Therefore, this study is aimed at evaluating the antimalarial effects, of its ethanolic extract and isolated compounds against Plasmodium falciparum 3D7 and P. berghei ANKA strains. Using chromatographic, spectrometric and spectroscopic techniques three compounds were isolated and characterised. The extract of S. debilis was active against P. falciparum 3D7, in an in vitro assay with IC50 of 12.0 ± 0.32 µg/ml. The three isolated compounds, namely 1,10-dihydroxy-6H-benzo[c]chromen-6-one (1), 8- hydroxy-3,4-dimethoxydibenzo[b,d]furan-1-carboxylic acid (2) and benzyl-2-methoxybenzoate (3), also showed antimalarial activity against Plasmodium berghei ANKA strain in curative and suppressive in vivo assays. The ethanolic extract and isolated compounds of S. debilis possess antimalarial effects. The isolated compounds may be responsible, at least in part, for the observed activities of the extract.

In vitro and in silico analysis for elucidation of antioxidant potential of Djiboutian Avicennia Marina (Forsk.) Vierh. phytochemicals

The present work aims to study the phytochemical composition, the antioxidant capacity of the crude extracts, and the fraction of extract giving the best antioxidant activity of Avicennia marina. The leaves contain high TFC compared to other parts of the plant, whereas fruits have the highest amount of TPC. Fat-soluble pigments are strongly present in the leaves of Avicennia marina i.e. β-carotene, lycopene, chlorophyll a, and chlorophyll b. The crude methanolic flower extracts showed strong DPPH and ABTS radical scavenging activity with IC50 values of 0.30 and 0.33 mg/mL respectively compared to the leaf and stem methanolic extracts for the DPPH and ABTS models with a value IC50 greater than 1 mg/mL. The crude fruit extract shows good activity with the ABTS model, unlike the DPPH model whose IC50 values are 0.95 and 0.38 mg/mL, respectively. Fractionation improved the antioxidant effect of crude flower extract. The ethyl acetate fraction exhibits the best antioxidant activity for both DPPH and ABTS methods with IC50 values of 0.125 and 0.16 mg/mL. The HR-LCMS/MS led to the identification of 13 compounds: 6 flavonoids and 7 iridoid glycoside compounds in the different parts of the plant. A bioinformatics study was performed to evaluate the antioxidant activity of the three major Iridoid glycosides towards the target protein Catalase compound II through free binding energy. Out of these three iridoid glycosides, compound C10 does not represent any toxicity, unlike C8 and C9 which showed an irritancy effect. Furthermore, molecular dynamics shows good stability of the C10-2CAG complex. HighlightsExtraction and fractionation of different part (leaf, stem, flower and fruit) of Avicennia marina.Botanical description and phytochemical analysis of crude extract methanolic. Investigation by HR-LCMS characterization of polyphenols and iridoid glycosides.Evaluation the antioxidant activity of crudes extracts methanolics by two methods in vitro DPPH and ABTS.Antioxidant activity of the fraction of the crude flower extracts presenting the best biological response.Evaluate the contribution of three major compounds 2'-Cinnamoylmussaenosidic acid, 10-O-[E-Cinnamoyl]-geniposidic acid and 10-O-[(E)-p-Coumaroyl]-geniposidic acid in the ethyl acetate fraction on the antioxidant activity through docking and dynamic molecular.Communicated by Ramaswamy H. Sarma.

Chemical Constituents and Biological Activities of Bruguiera Genus and Its Endophytes: A Review

The genus Bruguiera, a member of the Rhizophoraceae family, is predominantly found in coastal areas as a mangrove plant, boasting a rich and diverse community of endophytes. This review systematically compiled approximately 496 compounds derived from both the Bruguiera genus and its associated endophytes, including 152 terpenoids, 17 steroids, 16 sulfides, 44 alkaloids and peptides, 66 quinones, 68 polyketides, 19 flavonoids, 38 phenylpropanoids, 54 aromatic compounds, and 22 other compounds. Among these, 201 compounds exhibited a spectrum of activities, including cytotoxicity, antimicrobial, antioxidant, anti-inflammatory, antiviral, antidiabetic, insecticidal and mosquito repellent, and enzyme inhibitory properties, etc. These findings provided promising lead compounds for drug discovery. Certain similar or identical compounds were found to be simultaneously present in both Bruguiera plants and their endophytes, and the phenomenon of their interaction relationship was discussed.

Anti-leishmanial activity of Avicennia marina (Avicenniaceae family) leaves hydroalcoholic extract and its possible cellular mechanisms

Natural products are the main source of potent antioxidants and anti-leishmanial agents. This study was aimed to evaluate Avicennia marina (Avicenniaceae family) extract inhibitory effect against Leishmania tropica by accessing apoptotic markers and arginase activity. The A. marina were extracted and phytochemical analysis conducted. The inhibitory effect of A. marina was evaluated on L. tropica promastigote and amastigote forms, compared to meglumine antimoniate (Glucantime, MA) as standard drug. The level of apoptosis, Reactive Oxygen Species (ROS) production and arginase activity was assessed in A. marina-treated cells compared to control group. Phytochemical screening of A. marina extract showed strong presence of tannins and saponins. We demonstrated the inhibitory effect of A. marina on promastigote stages in a dose dependent manner. Also, lower 50% inhibitory concentration (IC₅₀) value of amastigotes was indicated in A. marina group compared with the standard group of Glucantime (60.57 ± 1.46 vs. 73.19 ± 10.12 μg/mL, respectively, P < 0.05). Besides, A. marina represented no cytotoxicity as the selectivity index (SI) was 10.7. Also, it showed the potential to induce early apoptosis of 46.5% in promastigotes at 125 μg/mL concentration. Significant reduction of arginase level was observed in both A. marina-treated cells and promastigotes. The promising results indicated higher effectiveness of A. marina in decreasing parasite growth, inducing apoptosis in promastigotes, increasing ROS production and decreasing arginase level. So, A. marina can be a native plant candidate for anti-leishmanial drug in tropical regions with cutaneous leishmaniasis due to L. tropica.

Antimalarial, Antioxidant, and Toxicological Evaluation of Extracts of Celtis africana, Grosseria vignei, Physalis micrantha, and Stachytarpheta angustifolia

In many parts of the world, malaria undoubtedly poses a serious threat to health care systems. Malaria treatment has increasingly become complicated, primarily due to the emergence of widespread resistance of the malaria parasites to cheap and affordable malaria therapeutics. The use of herbal remedies to treat various ailments, including malaria and malaria-like ailments in Ghana is common. We herein report on the antiplasmodial and antioxidant activities as well as toxicological evaluation of four medicinal plants (Celtis africana, Grosseria vignei, Physalis micrantha, and Stachytarpheta angustifolia) commonly used to treat malaria in Ghana. Following Soxhlet extraction of plant samples in ethanol, extracts were screened against Plasmodium falciparum (3D7 strain) in an in vitro antiplasmodial assay. The phosphomolybdenum and DPPH (1, 1-diphenyl-2 picrylhydrazyl) assays were used to evaluate antioxidant activities while toxicity assessment was carried out in mice using the acute toxicity test and kidney and liver function tests. Extracts from Celtis africana and Physalis micrantha were very active towards the parasites with half-maximal inhibitory concentrations (IC50's) of 29.1 and 3.5 µg/mL, respectively. Extracts of Grosseria vignei and Stachytarpheta angustifolia were inactive, having IC50 values greater than 50 µg/mL. All extracts exhibited excellent total antioxidant capacities (>800 mg/g AAE) and good DPPH radical scavenging potential (IC50 range of 300-900 µg/mL). The median lethal dose (LD50) of all extracts in the toxicological evaluation was greater than 2000 mg/kg and there was no effect of extracts on the levels and activities of key biomarkers of liver and kidney function. The activities of these plants obtained in this study partly give credence to their folkloric use in herbal medicines and suggest that they could provide promising lead compounds for malaria drug discovery programs.

In vitro antioxidant, antibacterial, and antihyperlipidemic potential of ethanolic Avicennia marina leaves extract supported by metabolic profiling

This study aimed to examine the impact of ethanolic Avicennia marina (A. marina) leaves extract against seven pathogenic bacteria and the protective effect of this plant against hyperlipidemia caused by dexamethasone (DEX)-treated rats. Forty-eight male rats weighing between 150 and 200 g were randomly selected into six groups containing eight rats in each group. Moreover, in vitro antioxidant DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free radical scavenging activity, FRAP (ferric reducing antioxidant power), and ABTS assay were also analyzed for leaf extract. Results showed that the IC₅₀ values were observed as 193.9 ± 1.03 μg/mL, 340.29 ± 8.16 μM TE/mg, and 326.8 ± 6.14 μM TE/mg for DPPH, FRAP, and ABTS radical scavenging activities, respectively. A. marina leaves ethanolic extract exhibited higher activity against Candida albicans and Bacillus subtilis, moderate activity against Salmonella typhimurium, and Vibrio damsel. The administration of DEX resulted in significant (P < 0.05) increase in the levels of MDA concentration, TG, TC, LDL, LDH, and glucose but decreased significantly in HDL. Treatment with A. marina extract positively reversed the distorted lipid profile and peroxidation and improved MDA, GSH, NO, and SOD activities in DEX-administered rats. Histological investigation of liver tissue sections showed that the treatment with A. marina leaves extract moderate the fatty change caused by DEX. It is concluded that A. marina leaves extract improved the hypolipidemic property of DEX administration in comparison with standard treatment with atorvastatin.

Biological Efficacy and Toxicological Evaluation of Ethanolic Extract of Cassia nodosa Buch.-Ham. (Leguminosae)

Medicinal plants are used worldwide to treat various diseases. However, scientific validation of the therapeutic potential of most medicinal plants is absent, and little to no information on their potential toxicity exists. It is therefore important to assess the efficacy and toxicity of various medicinal plants commonly used in traditional herbal medicine. The main goal of this study was to evaluate the efficacy and toxicity of the ethanolic extract of Cassia nodosa, a plant used in the treatment of fever, cold, gastric pain, diabetes mellitus, and malaria in Ghana. The stem bark extract of Cassia nodosa was obtained by cold maceration. Following phytochemical examination via standard procedures, the extract was screened for antiplasmodial, anti-inflammatory, and antioxidant activities. The extract was also evaluated for acute oral toxicity and its toxicity to the liver and kidney of rats. Phytochemicals present in the extract included sterols, alkaloids, tannins, glycosides, and coumarins. In the in vitro antiplasmodial activity test, the Cassia nodosa extract showed moderate antiplasmodial activity with an IC50 value of 23.98 ± 2.07 µg/ml. An ED50 value of 8.52 ± 2.83 mg/kg in the anti-inflammatory test indicated that the Cassia nodosa extract administered orally was very active in reducing inflammation. The total antioxidant capacity of the extract was determined to be 48.49 ± 5.24 gAAE/100 g with the total phenolic content being 28.48 ± 3.13 (gGAE/100 g) extract. In the DPPH radical scavenging assay, the concentration required for 50% inhibition of DPPH radical was found to be 78.71 ± 6.84 µg/mL. There was a gradual increase in the body weight of rats in both treated and control groups during the acute toxicity test. Clinical biochemical tests did not show any significant differences between control and treated groups of animals in terms of liver and renal functions, 14 days after administration of Cassia nodosa extracts. Taken together, these results provide scientific validation for the use of the plant in traditional medicine.

Phytochemical Screening, Antimicrobial and Antioxidant Activities of Selected Mangrove Species

Background:

Mangrove plant extracts are used in folkloric medicine as aphrodisiac, sedative, antioxidant, antimicrobial and antimalarial. Screening for antimicrobial, phytochemical and antioxidant activities of fourteen mangroves plant species (Aegiceras corniculatum, Acanthus ilicifolius, Avicennia alba, Avicennia marina, Avicennia officinalis, Bruguiera cylindrica, Bruguiera gymnorhiza, Ceriops tagel, Excoecaria agallocha, Kandelia candel, Rhizophora apiculata, Rhizophora mucronata, Sonneratia alba, and Sonneratia caseolaris) in various solvents are reported in this work.

Methods:

The antimicrobial screening was carried out using agar well diffusion method. In this study, nine pathogenic strains were used, including three Gram-positive and six Gram-negative bacteria. Phytochemical screening, total flavonoids, total phenolic and antioxidant activity was tested by DPPH radical scavenging assay. Four phenolic compounds (gallic acid, vanillin, tannic acid and quercetin) were quantified by LC-MS/MS in selected mangrove species.

Results:

Antimicrobial screening showed Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and Pseudomonas aeruginosa were most susceptible to ethyl acetate extract as compared to ethanol and methanol extract. Ethyl acetate extract of Avicennia marina and Bruguiera gymnorhiza showed strong antibacterial activity against Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and Pseudomonas aeruginosa. Phytochemical analysis revealed the presence of saponins, phenolics, flavonoids, alkaloids, tannins, and terpenoids, which was found to be variable as per the solvent used for extraction. In addition, total phenolics and total flavonoids content with different solvents were found in the range of 11.08 to 196.76 mg GAE/g and 12.92 to 110.3 mg QE/g of extract respectively. Moreover, antioxidant capacities expressed in terms of IC50 (mg/mL) showed that methanol extract exhibited higher antioxidant capacity followed by ethanol extract. LC-MS/MS analysis showed gallic acid and tannic acid are present in higher concentration in Aegiceras corniculatum and Sonneratia caseolaris than other species. The vanillin and quercetin were found in the least concentration.

Conclusion:

Mangroves species are rich source of antioxidant, phenolics and antimicrobial compounds.

Modulatory Effect of Polyphenolic Compounds from the Mangrove Tree Rhizophora mangle L. on Non-Alcoholic Fatty Liver Disease and Insulin Resistance in High-Fat Diet Obese Mice

No scientific report proves the action of the phytochemicals from the mangrove tree Rhizophora mangle in the treatment of diabetes. The aim of this work is to evaluate the effects of the acetonic extract of R. mangle barks (AERM) on type 2 diabetes. The main chemical constituents of the extract were analyzed by high-performance liquid chromatography (HPLC) and flow injection analysis electrospray-iontrap mass spectrometry (FIA-ESI-IT-MS/MS). High-fat diet (HFD)-fed mice were used as model of type 2 diabetes associated with obesity. After 4 weeks of AERM 5 or 50 mg/kg/day orally, glucose homeostasis was evaluated by insulin tolerance test (kiTT). Hepatic steatosis, triglycerides and gene expression were also evaluated. AERM consists of catechin, quercetin and chlorogenic acids derivatives. These metabolites have nutritional importance, obese mice treated with AERM (50 mg/kg) presented improvements in insulin resistance resulting in hepatic steatosis reductions associated with a strong inhibition of hepatic mRNA levels of CD36. The beneficial effects of AERM in an obesity model could be associated with its inhibitory α-amylase activity detected in vitro. Rhizophora mangle partially reverses insulin resistance and hepatic steatosis associated with obesity, supporting previous claims in traditional knowledge.

Antimalarial efficacy of Pongamia pinnata (L) Pierre against Plasmodium falciparum (3D7 strain) and Plasmodium berghei (ANKA)

Background

The objective of the current study was to assess the in vitro antiplasmodial activities of leaf, bark, flower, and the root of Pongamia pinnata against chloroquine-sensitive Plasmodium falciparum (3D7 strain), cytotoxicity against Brine shrimp larvae and THP-1 cell line. For in vivo study, the plant extract which has shown potent in vitro antimalarial activity was tested against Plasmodium berghei (ANKA strain).

Methods

The plant Pongamia pinnata was collected from the herbal garden of Acharya Nagarjuna University of Guntur district, Andhra Pradesh, India. Sequentially crude extracts of methanol (polar), chloroform (non-polar), hexane (non-polar), ethyl acetate (non-polar) and aqueous (polar) of dried leaves, bark, flowers and roots of Pongamia pinnata were prepared using Soxhlet apparatus. The extracts were screened for in vitro antimalarial activity against P. falciparum 3D7 strain. The cytotoxicity studies of crude extracts were conducted against Brine shrimp larvae and THP-1 cell line. Phytochemical analysis of the plant extracts was carried out by following the standard methods. The chemical injury to erythrocytes due to the plant extracts was checked. The in vivo study was conducted on P. berghei (ANKA) infected BALB/c albino mice by following 4-Day Suppressive, Repository, and Curative tests.

Results

Out of all the tested extracts, the methanol extract of the bark of Pongamia pinnata had shown an IC₅₀ value of 11.67 μg/mL with potent in vitro antimalarial activity and cytotoxicity evaluation revealed that this extract was not toxic against Brine shrimp and THP-1 cells. The injury to erythrocytes analysis had not shown any morphological alterations and damage to the erythrocytes after 48 h of incubation. Because methanolic bark extract of Pongamia pinnata has shown good antimalarial activity in vitro, it was also tested in vivo. So the extract had exhibited an excellent activity against P. berghei malaria parasite while decrement of parasite counts was moderately low and dose-dependent (P < 0.05) when compared to the control groups, which shown a daily increase of parasitemia, unlike the CQ-treated groups. The highest concentration of the extract (1000 mg/kg b.wt./day) had shown 83.90, 87.47 and 94.67% of chemo-suppression during Suppressive, Repository, and Curative tests respectively which is almost nearer to the standard drug Chloroquine (5 mg/kg b.wt./day). Thus, the study has revealed that the methanolic bark extract had shown promisingly high ((P < 0.05) and dose-dependent chemo-suppression. The phytochemical screening of the crude extracts had shown the presence of alkaloids, flavonoids, triterpenes, tannins, carbohydrates, phenols, coumarins, saponins, phlobatannins and steroids.

Conclusions

The present study is useful to develop new antimalarial drugs in the scenario of the growing resistance to the existing antimalarials. Thus, additional research is needed to characterize the bioactive molecules of the extracts of Pongamia pinnata that are responsible for inhibition of malaria parasite.

Dietary supplementation of Avicennia marina extract on immune protection and disease resistance in Amphiprion sebae against Vibrio alginolyticus

The effect of Avicennia marina aqueous leaf extract on innate immune mechanisms such as total white blood cell counts (WBC), serum lysozyme activity, respiratory burst assay, alternative complement (ACH50) assay, phagocytic activity assay, disease resistance, gut bacteria, and survival rate of clownfish (Amphiprion sebae) against Vibrio alginolyticus is reported. Healthy fish challenged with V. alginolyticus (1 × 10(7) cells ml(-1)) were fed with diets supplemented (0, 1, 2, and 4%) with A. marina extract. The survival rate was 85% and 80% in infected fish fed with 4% and 8% supplementation diet; with 1% diet it was 70% while in the infected untreated group it was only 10%. The total gut bacteria flora was high in 8% and 4% supplementation diet groups with 2.8 × 10(5) and 4.7 × 10(4) cfu/g while it was 8.9 × 10(3) cfu/g in 1% diet group. The immunological parameters significantly increased on weeks 6 and 8 when infected fish were fed with 1% or 4% supplementation diet. This study reports that in clownfish challenged with V. alginolyticus, dietary administration of the 1% or 4% of A. marina extract improved the immune status and survival rate.

Mangrove dolabrane-type of diterpenes tagalsins suppresses tumor growth via ROS-mediated apoptosis and ATM/ATR-Chk1/Chk2-regulated cell cycle arrest

Natural compounds are an important source for drug development. With an increasing cancer rate worldwide there is an urgent quest for new anti‐cancer drugs. In this study, we show that a group of dolabrane‐type of diterpenes, collectively named tagalsins, isolated from the Chinese mangrove genus Ceriops has potent cytotoxicity on a panel of hematologic cancer cells. Investigation of the molecular mechanisms by which tagalsins kill malignant cells revealed that it induces a ROS‐mediated damage of DNA. This event leads to apoptosis induction and blockage of cell cycle progression at S‐G2 phase via activation of the ATM/ATR—Chk1/Chk2 check point pathway. We further show that tagalsins suppress growth of human T‐cell leukemia xenografts in vivo. Tagalsins show only minor toxicity on healthy cells and are well tolerated by mice. Our study shows a therapeutic potential of tagalsins for the treatment of hematologic malignancies and a new source of anticancer drugs.

What's new?

Mangroves of genus Ceriops, widespread and highly utilized in China, are of growing interest in anticancer drug development due to their production of potentially cytotoxic diterpenoids and triterpenoids. Here, a group dolabrane‐type diterpenes known as tagalsins isolated from the species C. tagal are shown to possess potent killing effects on cancer cells of hematologic origin. Cell death was associated with the production of reactive oxygen species and DNA damage. In vivo, tagalsins significantly delayed the development of human T‐cell leukemia in a murine xenograft model.

In vitro antiplasmodial effect of ethanolic extracts of coastal medicinal plants along Palk Strait against Plasmodium falciparum

OBJECTIVE

To identify the possible antiplasmodial compounds from Achyranthes aspera (A. aspera), Acalypha indica (A. indica), Jatropha glandulifera (J. glandulifera) and Phyllanthus amarus (P. amarus).

METHODS

The A. aspera, A. indica, J. glandulifera and P. amarus were collected along Palk Strait and the extraction was carried out in ethanol. The filter sterilized extracts (100, 50, 25, 12.5, 6.25 and 3.125 µg/mL) of leaf, stem, root and flower extracts of A. aspera, A. indica, J. glandulifera and P. amarus were tested for antiplasmodial activity against Plasmodium falciparum. The potential extracts were also tested for their phytochemical constituents.

RESULTS

Of the selected plants species parts, the stem extract of A. indica showed excellent antiplasmodial activity (IC50= 43.81µg/mL) followed by stem extract of J. glandulifera (IC50= 49.14µg/mL). The stem extract of A. aspera, leaf and root extracts of A. indica, leaf, root and seed extracts of J. glandulifera and leaf and stem extracts of P. amarus showed IC50 values between 50 and 100 µg/mL. Statistical analysis revealed that, significant antiplasmodial activity (P<0.01) was observed between the concentrations and time of exposure. The chemical injury to erythrocytes was also carried out and it showed that there were no morphological changes in erythrocytes by the ethanolic extract of all the tested plant extracts. The in vitro antiplasmodial activity might be due to the presence of alkaloids, glycosides, flavonoids, phenols, saponins, triterpenoids, proteins, and tannins in the ethanolic extracts of tested plants.

CONCLUSIONS

The ethanolic stem extracts of P. amarus and J. glandulifera possess lead compounds for the development of antiplasmodial drugs.

Antiplasmodial activity of extracts of 25 cyanobacterial species from coastal regions of Tamil Nadu

CONTEXT

Marine cyanobacteria offer considerable potential to isolate new antimalarials to meet a pressing need of our times.

OBJECTIVE

To explore the antiplasmodial properties of marine cyanobacteria.

MATERIALS AND METHODS

Cyanobacterial samples collected from the coastal regions of Tamil Nadu were identified using light microscopy, and the strains were cultivated in ASN-III medium. Organic extracts (0-100 µg mL(-1)) of 25 in vitro mass-cultivated cyanobacteria, prepared using methanol: chloroform mixture (1:1 v/v) were evaluated for their antiplasmodial activity against chloroquine-sensitive and -resistant strains of Plasmodium falciparum by fluorescence-based SYBR Green I assay where chloroquine was used as a control. To detect the toxic effects of cyanobacterial extracts against red blood cells, the invasion, maturation, and growth rate of malarial parasites in cyanobacterial extracts pre-treated versus untreated erythrocytes were quantified microscopically. Mammalian cell line (HeLa) was used to determine cyanobacterial extract toxicity using the MTT assay.

RESULTS

The extracts of Lyngbya aestuarii Liebm. ex Gomont CNP 1005 (C12) Oscillatoria boryana BDU 91451 (C22) and Oscillatoria boryana Bory ex Gomont BDU 141071 (C18) showed promising antiplasmodial activity (IC50 = 18, 18, and 51 μg mL(-1) respectively) against Pf3D7. Pretreatment of red blood cells with IC100 of C12, C18, and C22 (40, 100, and 40 µgmL(-1), respectively) did not significantly influence the invasion, maturation, and growth rate of malarial parasites in comparison with untreated RBC controls suggesting a lack of toxicity to host cells. MTT assay based IC50 (>200 μg mL(-1)) of these extracts against HeLa cell line also indicates their high selectivity against the malaria parasite.

DISCUSSION AND CONCLUSION

These exploratory studies suggest the possibilities of development of new antimalarial compounds from marine cyanobacteria.

Can scientific evidence support using Bangladeshi traditional medicinal plants in the treatment of diarrhoea? A review on seven plants

Diarrhoea is a common disease which causes pain and may be deadly, especially in developing countries. In Bangladesh, diarrhoeal diseases affect thousands of people every year, and children are especially vulnerable. Bacterial toxins or viral infections are the most common cause of the disease. The diarrhoea outbreaks are often associated with flood affected areas with contaminated drinking water and an increased risk of spreading the water-borne disease. Not surprisingly, plants found in the near surroundings have been taken into use by the local community as medicine to treat diarrhoeal symptoms. These plants are cheaper and more easily available than conventional medicine. Our question is: What is the level of documentation supporting the use of these plants against diarrhoea and is their consumption safe? Do any of these plants have potential for further exploration? In this review, we have choosen seven plant species that are used in the treatment of diarrhoea; Diospyros peregrina, Heritiera littoralis, Ixora coccinea, Pongamia pinnata, Rhizophora mucronata, Xylocarpus granatum, and Xylocarpus moluccensis. Appearance and geographical distribution, traditional uses, chemical composition, and biological studies related to antidiarrhoeal activity will be presented. This review reveals that there is limited scientific evidence supporting the traditional use of these plants. Most promising are the barks from D. peregrina, X. granatum and X. moluccensis which contain tannins and have shown promising results in antidiarrhoeal mice models. The leaves of P. pinnata also show potential. We suggest these plants should be exploited further as possible traditional herbal remedies against diarrhoea including studies on efficacy, optimal dosage and safety.

Antagonistic properties of seagrass associated Streptomyces sp. RAUACT-1: a source for anthraquinone rich compound

OBJECTIVE

To identify the antibacterial potential of seagrass (Syringodium isoetifolium) associate microbes against bacterial pathogens.

METHODS

Eumeration of microbial associates were analyzed with leaf and root samples of Syringodium isoetifolium. MIC and MBC were calculated for bacterial pathogens with microbial associates. Phylogenetic and GC-MS analysis were calculated for Actinomycetes sp. (Act01) which was the most potent.

RESULTS

Of the isolated microbial associates phosphatase producing bacterial isolates were identified as maximum [(261.78±35.09) CFU×10(4)/g] counts in root sample. Of the selected microbial isolates Actinomycete sp (Act01) showed broad spectrum of antibacterial activity against antibiotic resistant and fish bacterial pathogens. Phylogenetic analysis of Act01 showed maximum identities (99%) with the Streptomyces sp. (GU5500072). The 16s rDNA secondary structure of Act01 showed the free energy values as -366.3 kkal/mol. The GC-MS analysis Act01 showed maximum retention value with 23.742 RT and the corresponding chemical class was identified as 1, 4-dihydroxy-2-(3-hydroxybutyl)-9, 10-anthraquinone 9, 10-anthrac.

CONCLUSIONS

In conclusion, Streptomyces sp. (GU045544.1) from Syringodium isoetifolium could be used as potential antibacterial agent.

In vitro and in vivo antiplasmodial activity of the root extracts of Brucea mollis Wall. ex Kurz

Malaria control is compromised worldwide by continuously evolving drug-resistant strains of the parasite demanding exploration of natural resources for developing newer antimalarials. The northeastern region of India is endemic for malaria characterized by high prevalence of drug-resistant Plasmodium falciparum strains. Many plants are used by the indigenous communities living in the northeast India in their traditional system of medicine for the treatment of malarial fever. Folklore claim of antimalarial property of one such plant Brucea mollis was evaluated in vitro and in vivo for antiplasmodial activity. Crude extracts from dried B. mollis root powder were prepared through soxhlet extraction using petroleum ether, methanol, and water sequentially. Methanol extract was further partitioned between chloroform and water. These extracts were tested in vitro against laboratory-adapted chloroquine-sensitive and chloroquine-resistant strains of P. falciparum. In in vitro evaluation, extracts were found more active on the chloroquine-sensitive strain. Methanolic-chloroform (IC(50) 5.1 μg ml(-1)) and methanolic-aqueous (IC(50) 13.9 μg ml(-1)) extracts recorded significant in vitro antiplasmodial activity which was also supported by their promising in vivo activity (ED(50) 72 and 30 mg kg(-1) bw day(-1), respectively) against chloroquine-resistant Plasmodium yoelli N-67 strain in Swiss albino mice. Methanolic-aqueous extract-treated mice survived on average for 14 days that was comparable to the reference drug chloroquine. This is the first report of antiplasmodial activity of B. mollis validating the traditional use of this plant as antimalarial in the northeast India and calls for further detailed investigations.

In vitro antiplasmodial activity of methanolic extracts from seaweeds of South West Coast of India

OBJECTIVE

To identify the in vitro antiplasmodial activity of seaweed plants against Plasmodium falciparumstrains.

METHODS

A total of eight seaweeds were collected from Kanyakumari district, Tamilnadu, India. The in vitro antiplasmodial activity was performed in 96 well plates against Plasmodium falciparum, and preliminary phytochemcial analysis were performed for the extracts.

RESULTS

Of the selected plants Enteromorpha intestinalis (2.61%) showed maximum percentage of extraction. The minimum concentration of inhibitory (IC50) value was observed with Chaetomorpha antennina [(26.37±4.14) μg/mL] further, the positive controls such as chloroquine and artemether showed antiplasmodial activities (IC50) with (19.10±5.93) and (6.03±0.21) μg/mL concentrations, respectively. The preliminary phytochemical analysis of the seaweed extracts showed a variety of phytochemical constituents such as carboxylic acids, phenols, protein, resins, steroids and sugars.

CONCLUSIONS

The antiplasmodial activity of the seaweed extract might due to the presence of sugars and phenolic compounds. From the present findings, it is concluded that, the seaweed extract of Chaetomorpha antennina can be further used as a putative antiplasmodial drugs in near future.