Essential Oils as Novel Anthelmintic Drug Candidates

In vitro anthelmintic efficacy of Ferulic and Sinapic acid against zoonotic cestode Hymenolepis diminuta (Rudolphi, 1819)

The present study is aimed to investigate potential in vitro anthelmintic efficacy of two phenolic compounds Ferulic acid and Sinapic acid against the parasite H. diminuta. Adult parasites collected from infected rat's intestine (maintained in our laboratory) were treated with 1, 2.5, 5, 10 and 20 mg/mL concentrations of both the compounds in RPMI-1640 media containing 1% Tween 20. Further, one group was treated in Praziquantel as a reference drug and another group of parasites were kept as control. The efficacy was evaluated on the basis of motility and mortality of the parasites. The paralyzed worms were further processed for the morphological and ultrastructural studies and observed through light and scanning electron microscopy. A significant dose-dependent efficacy was found in all treatment and decrease in relative movability value was also recorded in all the concentrations of two compounds treated parasites. The time taken for paralysis in 5 mg/mL of Ferulic acid and 10 mg/mL of Sinapic acid were 1.47 ± 0.04 h and 0.88 ± 0.03 h respectively which is accorded with the standard concentration of Praziquantel. Morphological micrographs revealed pronounced distortion and altered topography of scolex and tegument while histological study showed loss of uniform tegumental integrity with folds and cracks in the treated parasites. Further, extensive alteration in the scolex and irrevocable disruption all over the body surface with loss of trapezoid shape, shrinkage of tegument and sloughing off microtriches were observed in electron microscopic study. The study indicated that both the compounds possess strong activity against H. diminuta and further studies are required to understand their detailed mode of action to exploit them as potential alternative candidates for curing helminthiases.

Ovicidal activity and cytotoxicity of ethanolic extract of turmeric (Curcuma longa) and green tea (Camellia sinensis) to treat digestive parasite of sheep

Background

The Trichuris eggs are collected from naturally infected sheep. Natural antihelmintics such as herbal medicines are needed as an alternative, such as natural compounds from endemic plants.

Aim

This present study aims to evaluate the ovicidal activity and cytotoxicity effects of ethanolic extract of Curcuma longa (EECL) and Camelia sinensis (EECS) as a biological anthelmintic against the egg of Trichuris sp.

Methods

The Trichuris eggs are collected from naturally infected sheep. CMC-Na solution 1% was used as a control. The treatments were 0.12% EECL; 0.24% EECL; 0.15% EECS; 0.30% EECS; a combination of 0.12% EECL and 0.30% EECS; a combination of 0.24% EECL; and 0.15% EECS. Ovicidal activity testing by microscopic examination of eggs treated using different concentrations of EECL extract, EECS, and a combination of them. They were exposed for various times (7, 14, 21, and 28 days) and incubated at room temperature.

Results

The study shows that a combination of C. longa extract and tea extract exhibits good ovicidal anthelmintic activity against Trichuris sp. in sheep. Cytotoxicity examination using the 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyl tetrazolium bromide (MTT) test. Based on MTT data processed using regression analysis, the obtained LC50 from the administration of EECL, EECS, and a combination of both in a ratio of 1:1, 2:2, 1:2, and 2:1. The combination of EECL extract and EECS with the highest concentration produced cell viability of 28.46%, 17.25%, 56.01%, and 46.47%, respectively.

Conclusion

It can be concluded that the most cytotoxic ingredient is found in the combination of EECL and EECS (2:2) at 17.25% and the safest is in the ratio (1:2) at 56.01%.

Strongyloides infection screening in transplant candidates: What is the best strategy?

BACKGROUND

The potential that Strongyloides stercoralis infection has to cause major morbidity and high mortality when the disseminated form occurs in transplant patients is of particular concern.

METHODS

In this study, the objective was to observe S. stercoralis infection in patients who are candidates for transplantation by using parasitological, serological, and molecular techniques and to propose an algorithm for the detection of that infection in transplant candidates.

RESULTS

By parasitological techniques, 10% of fecal samples were positive. Anti-Strongyloides antibodies immunoglobulin G were detected in 19.3% and 20.7% of patients by immunofluorescence assay and enzyme-linked immunosorbent assay, respectively. S. stercoralis DNA was observed in 17.3% of samples by conventional polymerase chain reaction and 32.7% of samples by quantitative polymerase chain reaction (qPCR).

CONCLUSION

The set of results allows us to reinforce that a positive result by parasitological techniques and/or qPCR indicates that the specific treatment should be applied. However, the improvement of diagnostic techniques may suggest changes in the screening for strongyloidiasis in these patients.

The Effects of Honeysuckle (Lonicera caerulea L.) Berry Iridoid-Anthocyanin Extract on the Intestinal and Muscle Histopathology in Mice during Experimental Trichinellosis

The aim of the study was to determine the effect of iridoid-anthocyanin extract from honeysuckle (Lonicera caerulea L.) (LC) berries on histopathological changes in the intestines and muscles during experimental trichinellosis in mice. The LC extract was administered to uninfected mice (LC group) and Trichinella-spiralis-infected mice (T+LC) orally at a dose of 2 g/kg bw, six times at 24 h intervals, from day 3 prior to infection to day 3 post-infection (dpi). Jejunum samples were collected on 5, 7, 14, and 21 dpi, and their histological assessment involved the villus height to crypt depth ratio (VH/CD), goblet cell (GC) number, and morphological changes. In the T. spiralis-infected muscles, the extent of inflammatory infiltration on the 14th and 21st dpi was assessed. LC in the infected mice restored the VH/CD ratio to control values on 14 dpi. A beneficial effect of the LC extract on the villus height was also observed 14 dpi in the LC and T+LC groups. No differences in the extent of inflammatory infiltration in the muscles between the T+LC and T groups were observed. In conclusion, the iridoid-anthocyanin extract from honeysuckle berry contributed to alleviating the symptoms of the intestinal phase of T. spiralis infection.

Medical management of cystic echinococcosis

PURPOSE OF REVIEW

Cystic echinococcosis is a neglected zoonosis for which humans are dead end hosts. It is not only widely distributed in sheep rearing areas of low-income and middle-income countries but also has a significant presence in wealthy countries, for example, in Europe. It results in considerable morbidity, and its current management is far from optimal. Medical management is with a benzimidazole, with the addition of praziquantel under some circumstances.

RECENT FINDINGS

Interest in mebendazole as an anticancer drug has stimulated research into new drug formulations to improve bioavailability and possibly reduce inter-individual variability in in-vivo drug levels, which may help its activity against cystic echinococcosis. Further evidence to support administration of albendazole with a fatty meal has been provided. GlaxoSmithKilne (GSK) has agreed to extend its albendazole donation programme to include echinococcosis. The search for new drugs has focussed on natural products, such as essential oils and on repurposing of existing drugs licensed for human use against other conditions.

SUMMARY

The medical treatment of cystic echinococcosis remains sorely neglected, with no new drugs for almost 40 years. We need a better understanding of how to use the drugs we do have, whilst seeking new ones. Drug repurposing may be the best pathway.

Indirect Modulation by FLP-1 Peptides on Chemotaxis and Dispersal Behavior in C. elegans

Parasitic nematodes infect and cause morbidity in over one billion people worldwide, with current anthelmintic drugs decreasing in efficacy. To date, nematodes produce more types of neuropeptides than any other animal. We are interested in the role of neuropeptide signaling systems as a possible target for new anthelmintic drugs. Although FMRFamide-related peptides are found throughout the animal kingdom, the number of these peptides in nematodes greatly exceeds that of any other phylum. We are using Caenorhabditis elegans as a model for examining FMRFamide-like peptides, all of which share a C-terminal Arg-Phe-amide and which are known as FLPs in nematodes. Our previous work indicated interactions between the daf-10 , tax-4 , and flp-1 signaling pathways. In this paper, we further explore these interactions with chemotaxis and dispersal assays.

Invitro and in vivo anthelmintic efficacy of peppermint (Mentha x piperita L.) essential oil against gastrointestinal nematodes of sheep

Nowadays, the exclusive use of commercial anthelmintics for the treatment of gastrointestinal nematode infections in ruminants is less sustainable due to anthelmintic resistance, as well as the problem of drug residues in animal products and the environment. Therefore, an integrated therapeutic approach is needed, including the search for alternatives to synthetic anthelmintic drugs. The aim of this study was to evaluate the possibility of using the essential oil of peppermint (Mentha x piperita L.) in the control of gastrointestinal nematodes in sheep. For this purpose, the in vitro and in vivo anthelmintic efficacy of this oil and the toxic effects on the hosts were examined. In the in vitro egg hatch test, ovicidal activity varied from 21.0-90.3% depending on the concentration of essential oil used (0.0125, 0.025, 0.049, 0.195, 0.781, 3.125, 12.5, and 50 mg/mL). To some extent, anthelmintic efficacy was confirmed in the in vivo fecal egg count reduction test at a mean dose of 150 mg/kg, with an average reduction of nematode eggs of 26.9 and 46.0% at Days 7 and 14 after treatment, respectively. Furthermore, no toxic effects of applied oil were observed on sheep behavior, kidney, or liver function. The main compounds identified by gas chromatography-mass spectrometry analyzes were menthol (32.6%), menthone (22.0%), menthyl-acetate (10.0%), and isomenthone (9.39%). Due to their complex chemical compositions, numerous bioactive ingredients, and natural origin, herbal formulations represent a potentially valuable alternative for the control of gastrointestinal nematodes in sheep. In this context, the results of the present study showed that peppermint essential oil is one of the promising candidates. Further studies should be performed to collect more data on the safety profile of M. piperita EO in treated animals to find the most appropriate formulation for use in field conditions and to test it against resistant gastrointestinal nematode populations.

Biological Activity of Biosynthesized Silver Nanoaggregates Prepared from the Aqueous Extract of Cymbopogon citratus against Candida spp

Cymbopogon citratus is commonly used in folk medicine for the treatment of nervous and gastrointestinal disturbances and other medical issues because of its potent antioxidant capacity. The current study evaluated the anti-candida effects of silver nanoparticles (AgNPs) synthesized from an aqueous extract of C. citratus against different Candida spp. The aqueous extract was prepared from the fresh leaves of C. citratus. The silver nanoparticles (AgNPs) were prepared and validated by UV spectroscopy, Fourier-transform infrared spectroscopy (FTIR), transmission electron microscope (TEM), and zeta size analysis. C. albicans, C. krusei, C. parapsilosis, C. tropicalis, C. famata, C. rhodotorula, and C. glabrata were used in the antifungal assay. Microscopical imaging were used to investigate the different morphological changes induced by treatment. FTIR spectrum confirmed the existence of various functional groups of biomolecules capping the nanoparticles. The average particle size of synthesized AgNPs was 100.6 nm by zeta-sizer and 0.012 to 0.059 mm by TEM. In the antifungal assay, AgNPs aggregates induced significant inhibition of the growth of all species (p < 0.05) compared to the control and the biofilm maturation in C. famata and C. albicans. These considerable antifungal activities might lead to the development of appropriate alternative remedy for the treatment of fungal infections.

Plant Essential Oils as a Tool in the Control of Bovine Mastitis: An Update

Bovine mastitis is a major concern for the dairy cattle community worldwide. Mastitis, subclinical or clinical, can be caused by contagious or environmental pathogens. Costs related to mastitis include direct and indirect losses, leading to global annual losses of USD 35 billion. The primary treatment of mastitis is represented by antibiotics, even if that results in the presence of residues in milk. The overuse and misuse of antibiotics in livestock is contributing to the development of antimicrobial resistance (AMR), resulting in a limited resolution of mastitis treatments, as well as a serious threat for public health. Novel alternatives, like the use of plant essential oils (EOs), are needed to replace antibiotic therapy when facing multidrug-resistant bacteria. This review aims to provide an updated overview of the in vitro and in vivo studies available on EOs and their main components as an antibacterial treatment against a variety of mastitis causing pathogens. There are many in vitro studies, but only several in vivo. Given the promising results of treatments with EOs, further clinical trials are needed.

In vitro Evaluation of the Potent Antileishmanial Activity of Ferula tabasensis Alone or in Combination with Shark Cartilage Extract Against the Standard Iranian Strain of Leishmania major (MRHO/IR/75/ER)

Background

The available drugs for the treatment of leishmaniasis are highly toxic and extremely expensive, with low efficiency; therefore, the development of effective therapeutic compounds is essential.

Objectives

The present study aimed to explore the antileishmanial effects of ethyl acetate extract, methanol extract, and fractions 1-4 (F1-F4) of Ferula tabasensis, alone or in combination with shark cartilage extract (ShCE), on L. major in vitro.

Methods

In this study, ethyl acetate, methanol, and n-hexane extracts were extracted from the aerial roots of F. tabasensis by the maceration method. The silica gel column chromatography was used to separate n-hexane extracts at varying polarities (F1-F4 fractions). Subsequently, the effects of extracts and fractions against promastigotes were assessed by the parasite counting method microscopic inhibition test and MTT assay. Besides, their effects on the infected macrophage cells and the number of amastigotes were investigated. Cytotoxicity was evaluated in non-infected J774A.1 macrophage cells. Finally, apoptosis induction of promastigotes, including infected and non-infected macrophages, was evaluated.

Results

The results indicated the highly potent activity of F. tabasensis extracts and F1-F4 fractions, alone or in combination with ShCE, against L. major promastigotes and amastigotes in a dose-dependent manner (P < 0.05). The F1 fraction and methanol extract showed markedly higher toxicity compared to the other extracts and fractions, with 50% inhibitory concentrations (IC50/72h) of 2.4 ± 0.29 and 2.9 ± 0.55 µg/mL against promastigotes and 1.79 ± 0.27 µg/mL and 1.39 ± 0.27 µg/mL against amastigotes (P < 0.001). Moreover, they had a high selectivity index (SI) due to the low toxicity of macrophages (P < 0.0001). The results of flow cytometry indicated that the percentages of apoptotic promastigote cells in contact with IC50 concentrations of F1 and methanol extract alone after 72 h were 43.83 and 43.93%, as well as 78.4%, and 65.45% for their combination with ShCE, respectively.Also, apoptosis of infected macrophages induced by F1 and methanol extracts was estimated at 68.5% and 83.7%, respectively.

Conclusions

In this study, the F1 fraction and methanol extract of F. tabasensis showed potent efficacy against L. major, associated with low toxicity and apoptosis induction. Therefore, they can be promising therapeutic candidates in future animal and even human studies.