Ascorbic acid potentiates the Giardia duodenalis growth inhibitory activity of pure Terminalia ferdinandiana Exell compounds

Terminalia ferdinandiana Exell. extracts reduce pro-inflammatory cytokine and PGE2 secretion, decrease COX-2 expression and down-regulate cytosolic NF-κB levels

Based on their high antioxidant capacity and noteworthy phytochemistry, Terminalia ferdinandiana fruit and leaves have attracted considerable recent interest for their therapeutic potential. Whilst those studies have reported a variety of therapeutic properties for the fruit, the anti-inflammatory potential of T. ferdinandiana has been largely neglected and the leaves have been almost completely ignored. This study investigated the immune-modulatory and anti-inflammatory properties of T. ferdinandiana fruit and leaf extracts by evaluating their inhibition of multiple pro- and anti-inflammatory cytokines and chemokines secretion in lipopolysaccharide (LPS)-stimulated and unstimulated RAW 264.7 macrophages using multiplex bead immunoassays and ELISA assays. The methanolic extracts were particularly good immune-modulators, significantly inhibiting the secretion of all the cytokines and chemokines tested. Indeed, the methanolic extracts completely inhibited IL-10, IFN-γ, IL-1β, IL-6, MCP-1, and MIP-2a secretion, and almost completely inhibited the secretion of TNF-α. In addition, the methanolic T. ferdinandiana extracts also significantly inhibited cytosolic COX-2 levels (by 87-95%) and the synthesis of the PGE2 (by ~ 98%). In contrast, the methanolic extracts stimulated LTB4 secretion by ~ 60-90%, whilst the aqueous extracts significantly inhibited LTB4 secretion (by ~ 27% each). Exposure of RAW 264.7 cells to the methanolic T. ferdinandiana extracts also significantly down-regulated the cytosolic levels of NF-κB by 33-44%, indicating that the immune-modulatory and anti-inflammatory properties of the extracts may be regulated via a decrease in NF-κB transcription pathways. Taken together, these results demonstrate potent anti-inflammatory properties for the extracts and provide insights into their anti-inflammatory mechanisms.

Gallic acid and Catechin induce morphological alterations on the zoonotic parasite Hymenolepis diminuta

Tapeworm infections cause insidious and irreversible effects in the infected individuals and some of them have already shown resistance to available drugs. A search for alternative treatment is urgently required. Phenolic compounds are amongst the most researched natural substances for their medicinal use. The present study aims to determine anthelmintic efficacy of two polyphenols Gallic acid and Catechin against the zoonotic rat tapeworm Hymenolepis diminuta. Both compounds are potent anti-oxidants and play major roles in combating pathogens, while their anthelmintic property according to our knowledge is yet to be explored. The parasite model H. diminuta was procured from intestine of infected rats raised in our laboratory. Two sets of parasites were treated in vitro with 5, 10, 20 and 40 mg/ml concentrations of each Gallic Acid and Catechin separately, another set of parasites were treated with standard dose of Praziquantel in RPMI 1640, while still another set of worms were kept in RPMI 1640 at 37 ± 10C with 1% Dimethyl sulfoxide as control. Motility and structural alterations were the parameters assessed for anthelmintic efficacy of the compounds. After paralysis the worms were processed for morphological, histological, and ultrastructural study and observed under light and electron microscope. Dose-dependent efficacy was observed in both compounds. Shrinkage of suckers, deformed proglottids and architectural alteration of the tegument were observed throughout the body of treated parasites compared to control. Although in terms of time taken for paralysis and mortality Gallic acid was more effective than Catechin, the degree of morphological aberrations caused were almost similar, except histological alteration was more in Catechin treated worms than in Gallic acid. Nevertheless, both Gallic acid and Catechin are suggested to possess anthelmintic efficacy besides other health benefits but extended studies are required to compare their efficacy.

Antimicrobial resistance of the enteric protozoon Giardia duodenalis - A narrative review

Introduction

As therapy-refractory giardiasis is an emerging health issue, this review aimed at summarizing mechanisms of reduced antimicrobial susceptibility in Giardia duodenalis and strategies to overcome this problem.

Methods

A narrative review on antimicrobial resistance in G. duodenalis was based upon a selective literature research.

Results

Failed therapeutic success has been observed for all standard therapies of giardiasis comprising nitroimidazoles like metronidazole or tinidazole as first line substances but also benznidazoles like albendazole and mebendazole, the nitrofuran furazolidone, the thiazolide nitazoxanide, and the aminoglycoside paromomycin. Multicausality of the resistance phenotypes has been described, with differentiated gene expression due to epigenetic and post-translational modifications playing a considerable bigger role than mutational base exchanges in the parasite DNA. Standardized resistance testing algorithms are not available and clinical evidence for salvage therapies is scarce in spite of research efforts targeting new giardicidal drugs.

Conclusion

In case of therapeutic failure of first line nitroimidazoles, salvage strategies including various options for combination therapy exist in spite of limited evidence and lacking routine diagnostic-compatible assays for antimicrobial susceptibility testing in G. duodenalis. Sufficiently powered clinical and diagnostic studies are needed to overcome both the lacking evidence regarding salvage therapy and the diagnostic neglect of antimicrobial resistance.

The Therapeutic Properties of Plants Used Traditionally to Treat Gastrointestinal Disorders on Groote Eylandt, Australia

The First Australians had well-developed healing systems. Groote Eylandt inhabitants used a variety of plant species to treat diarrhoea and other gastrointestinal illnesses. This study was undertaken to test, identify, and evaluate traditional medicines to treat these conditions against gastrointestinal bacterial, protozoal, and viral pathogens, as well as against cancer cell proliferation. Six plant species (Buchanania obovata Engl., Casuarina equisetifolia L., Eucalyptus tetrodonta F. Muell., Planchonia careya (F. Muell.) R. Knuth, Terminalia carpentariae C. T. White, and Vigna vexillata (L.) A. Rich.) were selected from a survey of a panel of elders from the Warnindhilyagwa tribe and compared with the published literature. Decoctions prepared according to traditional methods were screened for growth inhibitory activity of a panel of diarrhoea-causing bacterial pathogens by disc diffusion and liquid dilution MIC assays. Inhibitory activity against the gastrointestinal protozoal parasite Giardia duodenalis and antiproliferative activity against human colorectal (Caco2) and cervical (HeLa) cancer cell lines were evaluated using MTS-based colorimetric cell proliferation assays. Preliminary antiviral screening was accomplished using an MS2 bacteriophage plaque reduction assay. Toxicity was evaluated using Artemia franciscana nauplii mortality and HDF cell viability bioassays. All traditional medicines tested inhibited bacterial growth, often with MIC values substantially <1000 μg/mL. T. carpentariae was particularly noteworthy, with MIC values of 230–350 μg/mL against Citrobacter freundii, Salmonella newport, Shigella sonnei, Staphylococcus aureus, and Staphylococcus epidermidis. This species also had MICs 450–950 μg/mL against all other bacterial pathogens. B. obovata Engl. and E. tetrodonta were also good inhibitors of bacterial growth, albeit with substantially higher MIC values than determined for T. carpentariae. The T. carpentariae decoction was also the best inhibitor of MS2 phage replication (IC₅₀ = 427 μg/mL) and Caco2 and HeLa proliferation (IC₅₀ values of 885 and 85 μg/mL, respectively). None of the extracts were particularly strong inhibitors of Giardia duodenalis growth. All decoctions were nontoxic in the Artemia nauplii and HDF cell viability bioassays, indicating their suitability for therapeutic use.

Plants of the Genus Terminalia: An Insight on Its Biological Potentials, Pre-Clinical and Clinical Studies

The evaluation and confirmation of healing properties of several plant species of genus Terminalia based on their traditional uses and the clinical claims are of utmost importance. Genus Terminalia has received more attention to assess and validate the therapeutic potential and clinical approval due to its immense folk medicinal and traditional applications. Various species of Terminalia genus are used in the form of herbal medicine and formulations, in treatment of diseases, including headache, fever, pneumonia, flu, geriatric, cancer, to improve memory, abdominal and back pain, cough and cold, conjunctivitis, diarrhea, heart disorder, leprosy, sexually transmitted diseases, and urinary tract disorders. These are reported to possess numerous biological properties, counting: antibacterial, antifungal, antiinflammatory, antiviral, antiretroviral, antioxidant, and antipa7rasitic. This current research review aims to update the detailed biological activities, pre-clinical and clinical studies of various extracts and secondary metabolites from several plant species under the genus Terminalia, along with information on the traditional uses and chemical composition to develop a promising strategy for their potential applications in the form of medicine or use in modern drug formulations for treating diseases like pneumonia, flu, and other types of viral infections or controlling human contagions.