Ellagitannins and simple phenolics from the halophytic plant Tamarix nilotica

Phytochemical and pharmacological properties of the genus Tamarix: a comprehensive review

The genus Tamarix in the Tamaricaceae family consists of more than 100 species of halophyte plants worldwide that are mainly used to improve saline-alkali land and for coastal windbreaks, sand fixation, and afforestation in arid areas. A considerable number of species in this genus are also used as traditional medicines to treat various human diseases, especially in Asian and African countries. This review presents a comprehensive summary of 655 naturally occurring compounds derived from the genus Tamarix, categorized into flavonoids (18.0%), phenols (13.9%), tannins (9.3%), terpenoids (10.5%), essential oils (31.0%), and others (17.3%). The investigation revealed that the crude extracts and phytochemicals of this genus exhibited significant therapeutic potential, including anti-inflammatory, anti-Alzheimer, anticancer, antidiabetic, antibacterial, and antifungal activities. Six species of Tamarix have anticancer effects by causing cancer cell death, inducing autophagy, and stopping cell division. Seven species from the same genus have the potential for treating diabetes by inhibiting α-glycosidase activity, suppressing human islet amyloid polypeptide, regulating blood glucose levels, and modulating autophagy or inflammation. The focus on antibacterial and antidiabetic effects is due to the presence of volatile oil and flavonoid components. Extensive research has been conducted on the biological activity of 30 constituents, including 15 flavonoids, 5 phenols, 3 terpenoids, 1 tannin, and 6 others. Therefore, future research should thoroughly study the mechanisms of action of these and similar compounds. This is the most comprehensive review of the phytochemistry and pharmacological properties of Tamarix species, with a critical assessment of the current state of knowledge.

Evaluation of Tamarix nilotica Fractions in Combating Candida albicans Infections

OBJECTIVES

Evaluation of the antifungal properties of Tamarix nilotica fractions against Candida albicans clinical isolates.

METHODS

The in vitro antifungal potential was evaluated by agar well diffusion and broth microdilution methods. The antibiofilm potential was assessed by crystal violet, scanning electron microscopy (SEM), and qRT-PCR. The in vivo antifungal activity was evaluated by determining the burden in the lung tissues of infected mice, histopathological, immunohistochemical studies, and ELISA.

RESULTS

Both the dichloromethane (DCM) and ethyl acetate (EtOAc) fractions had minimum inhibitory concentration (MIC) values of 64-256 and 128-1024 μg/mL, respectively. SEM examination showed that the DCM fraction decreased the biofilm formation capacity of the treated isolates. A significant decline in biofilm gene expression was observed in 33.33% of the DCM-treated isolates. A considerable decline in the CFU/g lung count in infected mice was observed, and histopathological examinations revealed that the DCM fraction maintained the lung tissue architecture. Immunohistochemical investigations indicated that the DCM fraction significantly (p < 0.05) decreased the expression of pro-inflammatory and inflammatory cytokines (TNF-α, NF-kB, COX-2, IL-6, and IL-1β) in the immunostained lung sections. The phytochemical profiling of DCM and EtOAc fractions was performed using Liquid chromatography-mass spectrometry (LC-ESI-MS/MS).

CONCLUSION

T. nilotica DCM fraction could be a significant source of natural products with antifungal activity against C. albicans infections.

Phytochemical investigation, antibacterial, and ameliorative potential effects of Tamarix nilotica on LPS-induced acute lung injury model in mice

Acute lung injury (ALI) is a serious illness with a high mortality rate of 40-60%. It is characterised by systemic inflammatory processes and oxidative stress. Gram-negative bacterial infections are the major cause of ALI, and lipopolysaccharide (LPS) is the major stimulus for the release of inflammatory mediators. Hence, there is an urgent need to develop new therapies which ameliorate ALI and prevent its serious consequences. The Middle Eastern native plant Tamarix nilotica (Ehrenb) Bunge belongs to the family Tamaricaceae, which exhibits strong anti-inflammatory and antioxidant effects. Thus, the current work aimed to ensure the plausible beneficial effects of T. nilotica different fractions on LPS-induced acute lung injury after elucidating their phytochemical constituents using LC/MS analysis. Mice were randomly allocated into six groups: Control saline, LPS group, and four groups treated with total extract, DCM, EtOAc and n-butanol fractions, respectively, intraperitoneal at 100 mg/kg doses 30 min before LPS injection. The lung expression of iNOS, TGF-β1, NOX-1, NOX-4 and GPX-1 levels were evaluated. Also, oxidative stress was assessed via measurements of MDA, SOD and Catalase activity, and histopathological and immunohistochemical investigation of TNF-α in lung tissues were performed. T. nilotica n-butanol fraction caused a significant downregulation in iNOS, TGF-β1, TNF-α, NOX-1, NOX-4, and MDA levels (p ˂ 0.05), and significantly elevated GPX-1 expression levels, SOD, and catalase activity (p ˂ 0.05), and alleviated all histopathological abnormalities confirming its advantageous role in ALI. The antibacterial activities of T. nilotica and its different fractions were investigated by agar well diffusion method and broth microdilution method. Interestingly, the n-butanol fraction exhibited the best antibacterial activity against Klebsiella pneumoniae clinical isolates. It also significantly reduced exopolysaccharide quantity, cell surface hydrophobicity, and biofilm formation.

Chemical profiling and cytotoxic potential of the n-butanol fraction of Tamarix nilotica flowers

BACKGROUND

Cancer represents one of the biggest healthcare issues confronting humans and one of the big challenges for scientists in trials to dig into our nature for new remedies or to develop old ones with fewer side effects. Halophytes are widely distributed worldwide in areas of harsh conditions in dunes, and inland deserts, where, to cope with those conditions they synthesize important secondary metabolites highly valued in the medical field. Several Tamarix species are halophytic including T.nilotica which is native to Egypt, with a long history in its tradition, found in its papyri and in folk medicine to treat various ailments.

METHODS

LC-LTQ-MS-MS analysis and ¹H-NMR were used to identify the main phytoconstituents in the n- butanol fraction of T.nilotica flowers. The extract was tested  in vitro for its cytotoxic effect against breast (MCF-7) and liver cell carcinoma (Huh-7) using SRB assay.

RESULTS

T.nilotica n-butanol fraction of the flowers was found to be rich in phenolic content, where, LC-LTQ-MS-MS allowed the tentative identification of thirty-nine metabolites, based on the exact mass, the observed spectra fragmentation patterns, and the literature data, varying between tannins, phenolic acids, and flavonoids. ¹H-NMR confirmed the classes tentatively identified. The in-vitro evaluation of the n-butanol fraction showed lower activity on MCF-7 cell lines with IC₅₀ > 100 µg/mL, while the higher promising effect was against Huh-7 cell lines with an IC₅₀= 37 µg/mL.

CONCLUSION

Our study suggested that T.nilotica flowers' n-butanol fraction is representing a promising cytotoxic candidate against liver cell carcinoma having potential phytoconstituents with variable targets and signaling pathways.

Salt-Tolerant Plants, Halophytes, as Renewable Natural Resources for Cancer Prevention and Treatment: Roles of Phenolics and Flavonoids in Immunomodulation and Suppression of Oxidative Stress towards Cancer Management

Halophytes and xerophytes, plants with adequate tolerance to high salinity with strong ability to survive in drought ecosystem, have been recognized for their nutritional and medicinal values owing to their comparatively higher productions of secondary metabolites, primarily the phenolics, and the flavonoids, as compared to the normal vegetation in other climatic regions. Given the consistent increases in desertification around the world, which are associated with increasing salinity, high temperature, and water scarcity, the survival of halophytes due to their secondary metabolic contents has prioritized these plant species, which have now become increasingly important for environmental protection, land reclamation, and food and animal-feed security, with their primary utility in traditional societies as sources of drugs. On the medicinal herbs front, because the fight against cancer is still ongoing, there is an urgent need for development of more efficient, safe, and novel chemotherapeutic agents, than those currently available. The current review describes these plants and their secondary-metabolite-based chemical products as promising candidates for developing newer cancer therapeutics. It further discusses the prophylactic roles of these plants, and their constituents in prevention and management of cancers, through an exploration of their phytochemical and pharmacological properties, with a view on immunomodulation. The important roles of various phenolics and structurally diverse flavonoids as major constituents of the halophytes in suppressing oxidative stress, immunomodulation, and anti-cancer effects are the subject matter of this review and these aspects are outlined in details.

Diterpenes and sterols from the Red Sea soft coral Sarcophyton trocheliophorum and their cytotoxicity and anti-leishmanial activities

The ethyl acetate and dichloromethane-soluble fractions, from a soft coral Sarcophyton trocheliophorum total methanolic extract, exhibited significant anti-leishmanial and cytotoxic activities. These active fractions yielded a new cembranoid diterpene (1), two known analogues [sarcotrocheliol (2) and sarcophine (3)], and two sterols [(24S)-24-methylcholesterol (4) and gorgosterol (5)]. The structure of the new diterpene (1) was determined via a detailed analysis of its spectroscopic data. Compounds 3 and 5 demonstrated noticeable cytotoxicity on A549 (IC₅₀ 17.4 ± 1.9 µg/ml) and HepG2 (IC₅₀ 17.7 ± 1.5 µg/ml) cell lines, respectively. None of the isolates 1‒5 showed detectable anti-leishmanial activity (IC₅₀ >100 µg/ml).

Design, Characterization, and Antimicrobial Evaluation of Copper Nanoparticles Utilizing Tamarixinin a Ellagitannin from Galls of Tamarix aphylla

The application of plant extracts or plant-derived compounds in the green synthesis of metal nanoparticles (NPs) was researched. Determining the exact metabolite implicated in the formation of NPs would necessitate comprehensive investigations. Copper nanoparticles (CuNPs) are gaining a lot of attention because of their unique properties and effectiveness against a wide range of bacteria and fungi, as well as their potential for usage in catalytic, optical, electrical, and microelectronics applications. In the course of this study, we aimed to formulate CuNPs utilizing pure tamarixinin A (TA) ellagitannin isolated from Tamarix aphylla galls. The main particle size of the formed CuNPs was 44 ± 1.7 nm with zeta potential equal to −23.7 mV, which emphasize the stability of the CuNPs. The X-ray diffraction spectroscopy showed a typical centered cubic crystalline structure phase of copper. Scanning electron microscopy images were found to be relatively spherical and homogeneous in shape. The antimicrobial properties of TA, as well as its mediated CuNPs, have been evaluated through well diffusion assays against four bacterial, Bacillus subtilis NCTC 10400, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Pseudomonas aeruginosa ATCC 27853, and two fungal, Candida albicans and Aspergillus flavus, strains. The distinctive antimicrobial activities were noted against the fungal strains and the Gram-negative bacterial strains P. aeruginosa ATCC 27853, and E. coli ATCC 25922. In conclusion, CuNPs mediated by TA can be applied for combating a wide range of bacterial and fungal species especially C. albicans, Asp. flavus, and P. aeruginosa in a variety of fields.

Antileishmanial and lung adenocarcinoma cell toxicity of Withania somnifera (Linn.) dunal root and fruit extracts

This study aims to evaluate the anti-Leishmania major and the lung adenocarcinoma (A549) cytotoxicity of Withania somnifera root and fruit. The total extracts were obtained by homogenisation in aqueous MeOH, and the sub-extracts [n-hexane, ethyl acetate (EtOAc), n-butanol (n-BuOH), and methanol (MeOH)] were obtained by flash chromatography. The activity evaluation showed that n-BuOH sub-extracts from root and fruit exhibited noticeable antileishmanial promastigote properties. The n-hexane and EtOAc sub-extracts from both organs, and the MeOH sub-extract from the fruit exerted mild to moderate effects on the promastigotes. In-vitro growth-inhibitory test results on axenic amastigote and cytotoxicity testing on macrophages (RAW264.7), the parasite-host at the amastigote stage, revealed that the activity was mainly concentrated in the root EtOAc and n-BuOH sub-extracts and to a lesser extent the fruit MeOH and EtOAc, and the root n-hexane sub-extracts. Only the roots' EtOAc and n-BuOH sub-extracts demonstrated low cytotoxicity on the A549 cell line.

Bacterial ClpP Protease Is a Potential Target for Methyl Gallate

Methyl gallate (MG) is an effective microbicide with great potential application in the integrated management of plant diseases and an important potential drug for clinical application. However, its target remains unknown. This study conducted a transposon sequencing (Tn-seq) under MG treatment in plant pathogenic bacterium Ralstonia solanacearum. Tn-seq identified that the mutation of caseinolytic protease proteolytic subunit gene clpP significantly increased the resistance of R. solanacearum to MG, which was validated by the in-frame gene deletion. iTRAQ (isobaric tags for relative and absolute quantitation) proteomics analysis revealed that chemotaxis and flagella associated proteins were the major substrates degraded by ClpP under the tested condition. Moreover, sulfur metabolism-associated proteins were potential substrates of ClpP and were upregulated by MG treatment in wild-type R. solanacearum but not in clpP mutant. Furthermore, molecular docking confirmed the possible interaction between MG and ClpP. Collectively, this study revealed that MG might target bacterial ClpP, inhibit the activity of ClpP, and consequently disturb bacterial proteostasis, providing a theoretical basis for the application of MG.

Role of ellagic acid for the prevention and treatment of liver diseases

Globally, one of the alarming problems is the prevalence and burden of liver diseases, which accounts for 2 million cases per year. Chronic liver aetiologies such as hepatitis infections, alcoholic or non-alcoholic liver disease, environmental agents, and drug-induced toxicity are invariably responsible for liver fibrosis progression to finally hepatocellular carcinoma. Current treatment options are unable to overwhelm and cure liver diseases. Emerging findings suggest researchers' interest in using evidence-based complementary medicine such as ellagic acid with extensive pharmacological properties. They include antioxidant, anti-inflammatory, anti-hyperlipidaemic, anti-viral, anti-angiogenic, and anticancer activity. The molecular functions elicited by ellagic acid include scavenging of free radicals, regulation of lipid metabolism, the prohibition of fibrogenesis response-mediating proteins, inhibits hepatic stellate cells and myofibroblasts, restrains hepatic viral replication, facilitates suppression of growth factors, regulates transcription factors, proinflammatory cytokines, augments the liver immune response, fosters apoptosis and inhibits cell proliferation in tumorigenic cells. This review will most notably focus on preclinical and clinical information based on currently available evidence to warrant ellagic acid's prospective role in preventing liver diseases.

Cytotoxic polyhydroxy sterols from the Egyptian Red Sea soft coral Sarcophyton acutum

The methanolic extract and its sub-extracts (viz, n-hexane, DCM, EtOAc and MeOH) of the soft coral Sarcophyton acutum were evaluated as anti-Leishmania major and as anticancer (against the HepG2, MCF-7, and A549 cell lines) using the MTT assay. Six polyhydroxy sterols (1-6) were isolated from the most active cytotoxic and anti-leishmanial EtOAc-soluble fraction. Their structures were established as two new polyhydroxy sterols, acutumosterols A (1) and B (2), and four known structural analogues (3-6) by intensive spectroscopic analyses, and by comparison with data of related compounds. Compound 4 exerted noticeable cytotoxicity against HepG2 cell line (IC₅₀ 17.2 ± 1.5 μg/mL), while the other pure isolates showed weak to moderate cytotoxicity (24.8 ± 2.8-57.2 ± 5.2). The results were discussed in relation to the structural features of these closely related sterols.