Antimicrobial activity of mangrove plant (Lumnitzera littorea)

Benefits of Manuka Honey in the Management of Infectious Diseases: Recent Advances and Prospects

The benefits of honey have been recognized since ancient times for treating numerous diseases. However, in today's modern era, the use of traditional remedies has been rapidly diminishing due to the complexities of modern lifestyles. While antibiotics are commonly used and effective in treating pathogenic infections, their inappropriate use can lead to the development of resistance among microorganisms, resulting in their widespread prevalence. Therefore, new approaches are constantly required to combat drug-resistant microorganisms, and one practical and useful approach is the use of drug combination treatments. Manuka honey, derived from the manuka tree (Leptospermum scoparium) found exclusively in New Zealand, has garnered significant attention for its biological potential, particularly due to its antioxidant and antimicrobial properties. Moreover, when combined with antibiotics, it has demonstrated the ability to enhance their effectiveness. In this review, we delve into the chemical markers of manuka honey that are currently known, as well as detail the impact of manuka honey on the management of infectious diseases up to the present.

Analysis of Unusual Sulfated Constituents and Anti-infective Properties of Two Indonesian Mangroves, Lumnitzera littorea and Lumnitzera racemosa (Combretaceae)

Lumnitzera littorea and Lumnitzera racemosa are mangrove species distributed widely along the Indonesian coasts. Besides their ecological importance, both are of interest owing to their wealth of natural products, some of which constitute potential sources for medicinal applications. We aimed to discover and characterize new anti-infective compounds, based on population-level sampling of both species from across the Indonesian Archipelago. Root metabolites were investigated by TLC, hyphenated LC-MS/MS and isolation, the internal transcribed spacer (ITS) region of rDNA was used for genetic characterization. Phytochemical characterization of both species revealed an unusual diversity in sulfated constituents with 3,3’,4’-tri-O-methyl-ellagic acid 4-sulfate representing the major compound in most samples. None of these compounds was previously reported for mangroves. Chemophenetic comparison of L. racemosa populations from different localities provided evolutionary information, as supported by molecular phylogenetic evidence. Samples of both species from particular locations exhibited anti-bacterial potential (Southern Nias Island and East Java against Gram-negative bacteria, Halmahera and Ternate Island against Gram-positive bacteria). In conclusion, Lumnitzera roots from natural mangrove stands represent a promising source for sulfated ellagic acid derivatives and further sulfur containing plant metabolites with potential human health benefits.

A comprehensive in silico and in vitro studies on quinizarin: a promising phytochemical derived from Rhizophora mucronata Lam

Mangrove plants are a great source of phytomedicines, since from the beginning of human civilization and the origin of traditional medicines. In the present study, ten different mangrove leaf methanolic extracts were screened for the type of phytochemicals followed by assessing antimicrobial, anti-oxidant and anti-cancer activities. The efficient methanolic crude extract of Rhizospora mucornata was further purified and characterized for the presence of the bioactive compound. Based on UV-visible spectroscopy, FTIR, NMR and HRMS analysis, the bioactive compound was 1,4-dihydroanthraquinone; also termed as Quinizarin. This identified compound was potential in exhibiting antimicrobial, antioxidant, and cytotoxic activity. Quinizarin inhibited the growth of Bacillus cereus and Klebsiella aerogenes with minimum inhibitory concentration (MIC) of 0.78 and 1.5 mg/ml. The DPPH free radical scavenging assay revealed the maximum activity of 99.8% at the concentration of 200 µg/ml with an IC50 value of 12.67 ± 0.41 µg/ml. Cytotoxic assay against HeLa (cervical) and MDA-MB231(breast) cancer cell lines revealed IC50 values to be 4.60 ± 0.26 and 3.89 ± 0.15 µg/ml. Together the results of molecular docking and molecular dynamics simulation studies explained that Quinizarin molecule showed stronger binding affinity (-6.2 kcal/mol) and significant structural stability towards anti-apoptotic Bcl-2 protein. Thus, the study put forth the promising role of the natural molecule - Quinizarin isolated from R. mucornata in the formulation of therapeutic drugs against bacterial infections and cancer. Communicated by Ramaswamy H. Sarma.

Potential of ethno-veterinary medicine in animal health care practices in the South Pacific Island countries: a review

The South Pacific island countries (SPIC) are among the most vulnerable countries in the world to economic shocks, climate change and natural disasters. Agriculture including livestock production makes important contribution to socio-economic development in the region. However, the livestock sector is marred by many livestock diseases, which are crippling the economies as well as threatening the food security of the island nations, most of which have high dependence on imports. Limited veterinary medical facilities, high cost of conventional medicine and remoteness of some rural farming communities make it difficult for farmers to treat their diseased animals. Nevertheless, the island nations are endowed with vast reserves of medicinal plants in diverse ecosystems including mangroves, rainforests and tropical dry forests. Despite the ubiquity of traditional medicine systems, most of the plant species have been used to treat human aliments in the SPIC and very few farmers utilise herbal medicine to treat their animals. This review highlights the common diseases affecting livestock production in the SPIC, threats to ethno-veterinary knowledge, and potential plant species and their efficacies to treat animal diseases and parasites. It also discusses the common methods of preparation of veterinary herbal medicine and possible ways of making the medicine available in the formal and informal markets in the region. It is envisaged that the review will stimulate further ethno-veterinary research among livestock disease management practices in the SPIC.

A New Flavone Glycoside From Lumnitzera littorea with In Vitro α-Glucosidase Inhibitory Activity

A new flavone glycoside, lumnitzerone (1), was isolated from leaves of Lumnitzera littorea, together with 9 known flavonoids. Their structures were elucidated by spectroscopic (one-dimensional, two-dimensional nuclear magnetic resonance) and high-resolution mass spectrometry analysis, and comparison with literature data. Extracts and all isolated compounds were evaluated for α-glucosidase inhibitory activity; all the extracts and most of the isolated compounds exhibited better activities than the positive control acarbose.

Enzymatic Activity of Endophytic Bacterial Isolates from Selected Mangrove Plants in Kenya

Introduction:

Microorganisms are a preferred source of enzyme production due to their high production capability and low cost of production. Bacterial endophytes occupy unexplored sites hence they represent a new source of enzymes with diverse applications. Mangrove plants in Kenya have traditionally been used as medicinal plants due to their bioactive metabolites. However the enzymatic activity of mangrove plants associated endophytes has not been studied.

Aims & Objectives:

The study is aimed at bioprospecting for enzymes with potential biotechnological applications from mangrove ecosystems.

Methods & Materials:

Forty-two bacterial isolates were cultured and isolated from the leaves and roots of six mangrove plants sampled from Mida Creek and Gazi Bay in the coastal region of Kenya. The isolates were screened for pectinases, chitinases, cellulases, proteases, and amylases. The isolates were identified based on morphology and 16S rRNA gene sequences analysis.

Results:

The study showed bacterial isolates had enzymatic activity as follows; pectinases activity (69% of the isolates), Proteases (95% of the isolates), amylases activity (88% of the isolates), cellulases and chitinases (92% of the isolates each). Bacterial endophytes from leaves showed a higher enzymatic index of cellulases suggesting a potential role in degrading cellulose in the leaves of plants. The enzymes amylases and proteases were mostly exhibited by endophytes in roots suggesting a potential role in metabolizing sugar and amino acids in the roots. Isolates from the mangrove plantSonneratia albashowed highest enzymatic indices. The study also observed that isolates from mangrove plants sampled from Gazi bay had high means of enzymatic indices. Molecular identification showed the isolates were closely related toBacillus, Streptomyces, Myroides, andStaphylococcusspecies. Their respective enzymatic activities have been provided in this study.

Conclusion:

The study showed that Kenyan Mangrove plant-associated bacterial endophytes provide a good reservoir of enzymes with potential industrial applications.

12-Hydroxycorniculatolide a from the Mangrove Tree, Lumnitzera littorea

A new macrocyclic lactone, 12-hydroxycorniculatolide A (1), along with three known compounds, corniculatolide A (2), 12-hydroxy-11- O-methyl-corniculatolide A (3) and 6,7-dimethoxycoumarin (4) were isolated from the methanolic extract of the twigs of Lumnitzera littorea. All compounds were characterized using spectroscopic methods. All compounds were screened against a panel of six Gram positive and five Gram negative bacteria.

Protective effect of apple mangrove Sonneratia caseolaris extract in Edwardsiella tarda-infected African catfish, Clarias gariepinus

Outbreaks of edwardsiellosis have severe impact on the aquaculture production of African catfish Clarias gariepinus. In this study, feed supplemented with apple mangrove Sonneratia caseolaris extract was evaluated for its protective effect against Edwardsiella tarda infection in African catfish. Results showed an increase in growth performance and higher survival rate in the treatment groups in a dose dependent manner. Haematological analyses showed an increase in white blood cell count in the treatment groups. Histopathological analysis revealed degenerative changes and regeneration of liver tissue architecture in both the control and treatment groups. However, the presence of inflammatory cells was found exclusively in the kidney of T3 treatment group that was supplemented with the highest dose of extract at 3.17 mg/ml, which inferred the activation of immune response in the fish. Contrast to the deteriorative alteration observed in the kidney of the control group due to E. tarda infection, treatment group exhibited tissue regeneration and well-defined kidney tissue architecture at 3 dpi. Taken together, these results demonstrated that supplementation with the methanol extract of S. caseolaris possesses protective effect in African catfish against the infection of E. tarda.

Antifungal activity of four honeys of different types from Algeria against pathogenic yeast: Candida albicans and Rhodotorula sp

OBJECTIVE

To evaluate the antifungal activity of four honeys of different types from Algeria against pathogenic yeast i.e. Candida albicans (C. albicans) and Rhodotorula sp.

METHODS

Four Algeria honeys of different botanical origin were analyzed to test antifungal effect against C. albicans, and Rhodotorula sp. Different concentrations (undiluted, 10%, 30%, 50% and 70% w/v) of honey were studied in vitro for their antifugal activity using C. albicans and Rhodotorula sp. as fungal strains.

RESULTS

The range of the diameter of zone of inhibition of various concentrations of tested honeys was (7-23 mm) for Rhodotorula sp., while C. albicans showed clearly resistance towards all concentrations used. The MICs of tested honey concentrations against C. albicans and Rhodotorula sp. were (70.09-93.48)% and (4.90-99.70)% v/v, respectively.

CONCLUSIONS

This study demonstrates that, in vitro, these natural products have clearly an antifungal activity against Rhodotorula sp. and C. albicans.

Antibacterial activity of leaves extracts of Trifolium alexandrinum Linn. against pathogenic bacteria causing tropical diseases

OBJECTIVE

To investigate antibacterial potential of Trifolium alexandrinum (T. alexandrinum) Linn. against seven gram positive and eleven gram negative hospital isolated human pathogenic bacterial strains responsible for many tropical diseases.

METHODS

Non-polar and polar extracts of the leaves of T. alexandrinum i.e., hexane, dichloromethane (DCM), ethyl acetate (EtOAc), methanol (MeOH) and aqueous (AQ) extracts at five different concentrations (1, 2, 5, 10 and 15 mg/mL) were prepared to evaluate their antibacterial value. NCCL standards were strictly followed to perform antimicrobial disc susceptibility test using disc diffusion method.

RESULTS

Polar extracts demonstrated significant antibacterial activity against tested pathogens. EtOAc and MeOH extracts showed maximum antibacterial activity with higher inhibition zone and were found effective against seventeen of the tested pathogens. While AQ plant extract inhibited the growth of sixteen of the test strains. EtOAc and MeOH plant extracts inhibited the growth of all seven gram positive and ten of the gram negative bacterial strains.

CONCLUSIONS

The present study strongly confirms the effectiveness of crude leaves extracts against tested human pathogenic bacterial strains causing several tropical diseases. Since Egyptian clover is used as a fodder plant, it could be helpful in controlling various infectious diseases associated with cattle as well.

Medicinal potential of Morella serata (Lam.) Killick (Myricaceae) root extracts: biological and pharmacological activities

BACKGROUND

Morella serata is a South African medicinal plant used in the treatment of microbial infections and to enhance male sexual performance. There is dearth of information in scientific literature on its efficacy and safety.

METHODS

In the present study, the root extracts were investigated for the phytochemicals that may be present the antibacterial, anticandida activity using 96 wells microtitre plate method and cytotoxicity using brine shrimp (Artemia salina) lethality assay.

RESULTS

The qualitative phytochemical screening revealed the presence of tannins, saponins, flavonoids, terpenoids and steroids. All the extracts including water inhibited both Gram positive and Gram negative bacteria strains at minimum inhibitory concentrations (MIC) ranging from 0.09 - 6.25 mgmL-1. The best activity was observed in the acetone extract inhibiting all the bacteria tested at MIC range of 0.09 - 0.78 mgmL-1 except Shigella flexneri KZN that was inhibited at 1.56 mgmL-1. Similarly, all the extracts suppressed the growth of all Candida species and Trichophyton mucoides at MIC ranging from 0.13 - 3.13 mgmL-1. The cytotoxicity assay revealed potent cytotoxic potential of M. serata methanol and ethanol root extracts by displaying LC50 of 0.26 and 0.18 μgmL-1 respectively.

CONCLUSION

The results obtained from the present study indicated broad spectrum antimicrobial activity and justifies the use of the plant in the treatment of infectious diseases. Also the species could be a good natural source of antitumor compounds considering its lethality against brine shrimp nauplii.