The genus Avicennia comprises eight species of mangrove trees that occur in intertidal zones of estuaries and seabeds found in tropical and temperate regions spanning throughout the world. The plan...

https://www.tandfonline.com/doi/pdf/10.1080/21553769.2016.1235619

The genus Avicennia, a pioneer group of dominant mangrove plant species with potential medicinal values: a review

Studies on phytochemical, antioxidant, antimicrobial analysis and separation of bioactive leads of leaf extract from the selected mangroves

Avicennia officinalis is a medicinally important mangrove plant and used in traditional medicinal practices to treat various ailments like rheumatism, paralysis, asthma, dyspepsia, tumors etc. The objective of the present study was to evaluate the carbohydrate metabolizing enzyme inhibitory, antioxidant, antimicrobial and cytotoxic potentials of ethanol leaf and bark extracts of A. officinalis. The carbohydrate metabolizing enzyme inhibition potential was studied by α-amylase and α-glucosidase inhibitory activities. The antioxidant activity was investigated by measuring the scavenging potential of extracts against DPPH, ABTS and superoxide radicals. The antimicrobial activity was studied by agar well diffusion method and the cytotoxicity potential by MTT assay. The study revealed that A.offiicnalis bark extract inhibited the activity of α-amylase and α-glucosidase in a dose dependent manner with an IC50 value of 0.66 and 0.71 mg/ml respectively. The leaf extract also demonstrated inhibition potential against α-amylase and α-glucosidase with an IC50 value of 0.29 and 1.19 mg/ml respectively. The ethanol bark extract also exhibited scavenging potential against DPPH, ABTS and superoxide radicals in a dose dependent manner with IC50 values of 112, 114 and 82 μg/ml respectively and ethanol leaf extract with IC50 values of 200, 41.9 and 207.6 μg/ml respectively. Both leaf and bark extracts exhibited dose dependent antiproferative activity on TC1 murine cell lines. Both leaf and bark extracts exhibited antimicrobial activity against bacteria (Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa and fungi (Candida albicans, C. krusei). The qualitative phytochemical assay, UV-Vis and FTIR analysis revealed the presence of different phytoconstituents in the leaf and bark extracts of A.officinalis. The results suggest that ethanol leaf and bark extracts of A.officinalis were effective in inhibiting α-amylase and α-glucosidase and also have antioxidant, antimicrobial potentials which justify the ethnobotanical use of this plant.

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Pharmacological activities of leaf and bark extracts of a medicinal mangrove plant Avicennia officinalis L.

Mangroves being stress tolerant plants possess unique metabolites with significant amount of bioactive compounds which could be isolated and evaluated for possible drug development with suitable biotechnology tools. The mangrove genus Xylocarpus comprises of four species viz. Xylocarpus granatum (Koenig), X. moluccensis (lamk.) and X. mekongensis Pierre and X. rumphii. However, X. rumphii is a less abundant mangrove plant. There have been reports that different species of Xylocarpus are used ethnomedicinallly for treatment of various diseases such as fever, malaria, cholera, diarrhoea, swelling of breast, elephantiasis, inflammation, dyslipidemia, pain, hyperglycaemia etc. Recent studies revealed that the extracts from different parts of the plant such as leaves, stem, bark and fruits possess phytoconstituents like alkaloids, glycosides, steroids, limnoids, terpenoids, flavonoids, tannins and other phenolics. Further, it has been established that the different solvent extracts of the plants have exhibited antimicrobial and antidiarrhoeal activities against a number of human pathogens which could be correlated to their phytoconstituents such as flavonoids, alkaloids, limnoids, tannins etc. The present study is aimed at compiling information on phytochemical, pharmacological and ethnomedicinal properties of mangrove plants of genus Xylocarpus, with a view to critically assess the legitimacy of the use of these plants for antimicrobial and antidiarrhoeal activities as well as providing directions for further research.

Ethnomedicinal, Antimicrobial and Antidiarrhoeal Studies on the Mangrove Plants of the Genus Xylocarpus: A Mini Review

Intrarenal 1-methoxypyrene, an aryl hydrocarbon receptor agonist, mediates progressive tubulointerstitial fibrosis in mice

Avicennia officinalis (AO) is an evergreen mangrove tree that finds a prominent place in folk medicine. In this study, we have quantified 2 significant phytochemicals viz., phenols and flavonoids and studied the antibacterial activity of extracts of AO fruits in ethyl acetate, acetone, methanol and ethanol against 8 pathogenic bacterial species E. coli , En. aerogenes , K. pneumoniae , P. aeruginosa , B. subtilis , L. delbrueckii , S. aureus and  Strep. pyogens . Phenols and flavonoids were quantified Spectrophotometrically. Total phenolic content (TPC) ranged from 125-350mg of GAE/g of crude extract and the flavonoid levels were in the range of 60-192 mg of rutin equivalent/g of dry sample. The methanol and ethanol extracts showed highest levels of TPC, while acetone extract was identified to contain comparatively elevated amounts of flavonoids. Antibacterial activity of all the extracts was screened against the selected strains by agar well diffusion method. All the extracts exhibited different degrees of inhibition against the bacterial strains tested.  Their MIC values ranged between 1.25-5.0mg/100µl. Methanol and Ethanol extracts showed strong inhibitory activities against both Gram negative and Gram positive bacterial strains compared to those of other extracts. However, ethyl acetate infusion restricted its activity only against the Gram positive bacterial strains tested. Strains of E. coli , En. aerogenes (Gram negative) S. aureus and  Strep. pyogens (Gram positive) were inhibited by acetone extract. This study provides the necessary data for isolation and characterization of individual broad spectrum antibacterial compounds from different extracts of AO fruits. The study also supports the potentiality of AO in folk medicine. Keywords:  Avicennia officinalis , Phenols, Flavonoids, Antibacterial

Quantification of phytochemicals and antibacterial activity of fruit extract of avicennia officinalis

Majority of regular synthetic antibiotics are in the process of being labeled out-dated owing to multi drug resistance among pathogens. Consequently researchers are devoting interest towards identification and isolation of potent antibacterial compounds from available herbal sources. Aim: The present study was aimed at evaluation of tannin levels, antioxidant potential and antibacterial activity of Avicennia marina L (AM) extracts on selected Gram positive and Gram negative bacterial species. Methods: Stem extracts prepared in different solvents in the order of increasing polarity (ethyl acetate, acetone, ethanol and methanol) were subjected to – quantification of tannins by Folin-Denis method, antioxidant capacity by ABTS and Blue Cro5 method and antibacterial activity by agar well diffusion method against selected bacterial species. The zones of inhibition obtained were measured and the results were statistically analysed. Results: Tannin level was found to be significantly high in methanol extract followed by that in ethanol, acetone and ethyl acetate. Extract in all the solvents showed antioxidant activity. However, extracts in methanol and ethanol exerted higher potentials. Like wise, extracts in all the solvents showed various degrees of antibacterial activity against the test cultures used. The methanol extract on Bacillus subtilis, Staphylococcus aureus and Streptococcus pyogens exhibited higher activity than that of Gentamicin. Conclusions: The present experimental data reveals that the stem of AM is rich in tannins and exhibits potential antioxidant and antibacterial activities. A comparative analysis is also provided with respect to the solvent used for the study of bioactivities.

Quantification of tannins, antioxidant capacity and antibacterial activities of stem extracts of avicennia marina (l)

Objective: The antibacterial principle of Avicennia marina L stem extract was determined by agar well diffusion method followed by GC-MS, 1 H NMR and 13 C NMR. Methods : Methanol was used as the solvent for the isolation of bioactive principle from the stem of Avicennia marina L. Agar well diffusion method was used to screen the antibacterial activity and FRAP method was employed to determine the antioxidant activity for raw and crude extract as well as the purified compound. GC-MS followed by 1 H NMR and 13 C NMR were used to elucidate the compound responsible for the antibacterial and antioxidant activity. Results : The degree of antioxidant and antibacterial activity differs between raw extract, crude extract and the pure compound. The antioxidant activity is more crude extract (p<0.05) and the antibacterial activity is more of pure compound (p<0.05) than the standard antibiotic gentamicin. GC-MS followed by 1 H NMR and 13 C NMR revealed that the compound is 2-propenoicacid, 3-(4-hydroxy-3-methoxyphenyl)- also called ferulic acid. Conclusion : The stem extract in methanol shows potential antibacterial and antioxidant activity. It is due to presence of ferulic acid in methanol extract in 14 th fraction.

Isolation and purification of antibacterial principle from avicennia marina l in methanol

Most of the human diseases are mediated by microorganisms. The discovery of antimicrobials provides an increasingly important tool to combat microbial diseases. Improp er usage of antimicrobials results in the developme nt of microbial resistance. Therefore, identification of new antimi crobial compounds is essential. Traditional medicin e still plays an important role in the health care in India and othe r countries. The mangrove ecosystem is a largely un explored source for the potential biologically active secondary metabol ites. Consequently, we set out to screen the stem o f Avicennia alba collected from the Coringa Mangrove Reserve Forest, Kakinada, East Godavari, Andhra Pradesh, India for antibacterial activity. In the present study, the stem extract of Avicennia alba in Hexane, Benzene, Chloroform, Ethylacetate, Methanol, Acetone, Absolute Alcohol & Water were screened for the antibacterial activity by Agar well diffusion method against selected microorganisms, viz, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Klebsi ella pneumonia (drug resistant strains) Pseudomonas aeruginosa, Enterobacter aerogenes, Clo stridium perfringens & Bacillus subtilis (drug sensitive strains) . The extracts were also screened for secondary meta bolites like flavanoids, alkaloids, saponins, terpenoids, steroids and tanni ns. None of the extracts were found effective again st the tested drug resistant strains irrespective of Gram nature. Whil e, Methanol extract is active against E.aerogenes & Bacillus subtilis and Chloroform, Acetone, Absolute Alcohol & aqueous extracts exhibited only anti E. aerogenes activity. However, Hexane, Benzene & Ethyl acetate solubles does not show any activity on the tested cultures. Phytochemi cal studies support the antibacterial activity of methanol, ace tone, alcohol & water solubles of A.alba . This clearly indicates that the active principles of A.alba stem are positive against drug sensitive strains b ut not to the drug resistant strains.

EVALUATION OF ANTIBACTERIAL ACTIVITY ON SELECTED BACTERIA AND SCREENING OF SECONDARY METABOLITES OF Avicennia Alba STEM

Antioxidant activity of Avicenni marina L and Avicennia officinalis L fruit extracts in ethyl acetate, acetone,
methanol and ethanol were studied by ABTS, CrO5 and FRAP method. All the extracts possessed..

A. Srinivasulu

Papers

Quantification of phytochemicals and antibacterial activity of fruit extract of avicennia officinalis

Quantification of tannins, antioxidant capacity and antibacterial activities of stem extracts of avicennia marina (l)

Isolation and purification of antibacterial principle from avicennia marina l in methanol

EVALUATION OF ANTIBACTERIAL ACTIVITY ON SELECTED BACTERIA AND SCREENING OF SECONDARY METABOLITES OF Avicennia Alba STEM

Evaluation of antioxidant activity in fruit extracts of Avicennia Marina L and Avicennia Officinalis L