Effect of Piper betle on Giardia intestinalis infection in vivo

Evaluation of the Antiparasitic, Antihepatotoxicity, and Antioxidant Efficacy of Quercetin and Chitosan, Either Alone or in Combination, against Infection Induced by Giardia lamblia in Male Rats

Giardia lamblia (G. lamblia) is one of the most common protozoal infections and a key cause of malabsorption, some cases of mental developmental issues in children, and reduced body weight. The known antiparasitic medications, which are the standard drugs used for parasitic treatment, have several side effects and sometimes exhibit low efficacy. Therefore, the current study aimed to evaluate the treatment with quercetin (QC) or chitosan (CH), either alone or in combination, as possible alternative therapeutic agents that may alleviate the side effects of G. lamblia infections and restore the normal architecture of the intestinal muscles. They are investigated as alternatives to other routinely administered drugs that may gradually lose their efficacy due to human resistance to therapeutic agents. This study was carried out on 50 male albino rats that were divided into five groups with 10 rats in each group: the control group (Group I), the infected non-treated group (Group II), the infected group treated with QC (Group III), the infected treated group with CH (Group IV), and the infected group treated with a combination of QC and CH (Group V). The effect was first evaluated by counting the G. lamblia fecal cysts in the stool, examining histopathological sections of the intestine with the appearance of trophozoites in the infected group, and conducting a transmission electron microscopic examination of the tissues of the small intestine. Alterations in the biochemical parameters of liver and kidney function and the antioxidant enzymes in the liver tissues of SOD, CAT, and GSH, and non-enzymatic markers of lipid peroxidation (MDA) were evaluated. The results showed a significant decline in the number of parasites in the stool samples, with a marked elevation in the number of trophozoites in the intestinal sections of the infected non-treated group as compared to the infected treated groups. The last group, which was treated with a combination of QC and CH, showed the best results in terms of a decline in the infection rate of G. lamblia in stool samples, with a marked and clear improvement in the intestinal mucosa, regular muscles with normal enteric ganglions, and reduced rates of intestinal injuries caused by G. lamblia trophozoites. Both QC and CH had non-toxic effects on the biochemical parameters of the liver and kidneys, as well as pronounced antioxidant activities due to the elevation of SOD, CAT, and GSH in conjunction with a decline in the levels of MDA. A combination of QC and CH can be considered a potent antiparasitic, anti-hepatotoxic, and antioxidant therapeutic agent; it could constitute a promising alternative treatment agent against G. lamblia infection.

Therapeutic Effect of Chitosan Nanoparticles and Metronidazole in Treatment of Experimentally Giardiasis Infected Hamsters

Background:

The present study aimed to assess the therapeutic effect of chitosan nanoparticles and metronidazole against Giardia lamblia as well as evaluate the efficacy of loading metronidazole on chitosan nanoparticles.

Methods:

This study was carried out at medical Parasitology Department, Faculty of Medicine, Zagazig University and Theodor Bilharz Research institute (TBRI) from February 2019 to February 2020 on 45 hamsters. They were divided into 5 groups 9 hamsters each: Group A non-infected hamsters, Group B infected control group, Group C, D and E infected with G. lamblia and treated with Chitosan nanoparticles (CsNPs), metronidazole (MTZ) and metronidazole-loaded chitosan nanoparticles (MTZ-CsNPs) respectively.

Results:

The highest percentage of reduction in the Giardia cyst and trophozoite counts were in group that received MTZ-CsNPs (94.69%, 94.29%). Lower percentages of reduction were recorded for MTZ treated group (90.15%, 89.52%) and CsNPs treated group (63.64%, 75.24%). Histopathological examination showed marked healing of intestinal mucosa after treatment with MTZ-CsNPs.

Conclusion:

CsNPs showed a therapeutic effect against Giardia infection in hamsters. Loading of metronidazole on chitosan nanoparticles enhanced therapeutic effect of both CsNPs as well as metronidazole.

Preventive role of probiotic bacteria against gastrointestinal diseases in mice caused by Giardia lamblia

Giardiasis is one of the most prevalent gastrointestinal diseases in the world. It is caused by Giardia, Giardia lamblia, a common and opportunistic zoonotic parasite. The aim of our work is to find a natural and safe alternative treatment for giardiasis, specifically, to determine if probiotic bacteria (Lactobacillus acidophilus, Bifidobacterium bifidum, and Lactobacillus helveticus) can contribute to treatment, and act as preventives. Sixty weanling albino mice, Mus musculus, were divided into control and experimental, probiotic-fed groups. We determined infection intensity, and cure and prevention rates of giardiasis through ELISA (enzyme-linked immunosorbent assay) of stool samples and histopathological comparison of intestinal tissue. In experimental groups, there was a significant reduction in infection intensity (P<0.001) on days 10, 15, and 20, while cure rate reached 87.5%. The control group showed no signs of reduced infection or cure and only the group treated with probiotics prior to infection showed significant prevention rates. In the experimental groups, intestinal changes due to giardiasis appeared 7 days post-infection. However, almost all of these changes disappeared by the 25th day. Our results suggest a beneficial and significant effect of probiotics in the prevention and treatment of giardiasis in mice.

Efficacy of Ageratum conyzoides extracts against Giardia duodenalis trophozoites: an experimental study

Background

Giardia duodenalis causes giardiasis in humans, particularly in developing countries. Despite the availability of treatments, resistance to some of the commercial anti-Giardia drugs has been reported in addition to their harmful side effects. Therefore, novel treatments for giardiasis are required. In this study, we aimed to assess the in vitro activity of crude extracts of Ageratum conyzoides against G. duodenalis trophozoites.

Methods

Plants were classified into three groups based on their flower colors: white (W), purple (P), and white–purple (W–P). Plants were separately cut into leaf (L) and flower (F) parts. Changes in internal organelle morphology of trophozoites following exposure to crude extracts were assessed using transmission electron microscopy (TEM). In subsequent experiments, efficacy of the most active essential oils from crude extracts [half maximal inhibitory concentrations (IC₅₀) ≤ 100 μg/mL] against G. duodenalis trophozoites was tested. In vitro anti-Giardia assays using essential oils were performed in the same way as those performed using crude extracts.

Results

LW–P and FP extracts showed high activity (IC₅₀ ≤ 100 μg/mL) against G. duodenalis trophozoites, with IC₅₀ ± SD values of 45.67 ± 0.51 and 96.00 ± 0.46 μg/mL, respectively. In subsequent experiments, IC₅₀ ± SD values of LW–P and FP essential oils were 35.00 ± 0.50 and 89.33 ± 0.41 μg/mL, respectively. TEM revealed the degeneration of flagella and ventral discs of G. duodenalis trophozoites following exposure to crude extracts.

Conclusion

Crude LW–P and FP extracts of A. conyzoides showed the highest activity against G. duodenalis. Exposure to crude extract induced changes in the flagella and ventral discs of G. duodenalis trophozoites, which play important roles in attachment to the surface of mucosal cells. Our results suggest that the tested extracts warrant further research in terms of their efficacy and safety as giardiasis treatment.

Drug resistance in Giardia: Mechanisms and alternative treatments for Giardiasis

The use of chemotherapeutic drugs is the main resource against clinical giardiasis due to the lack of approved vaccines. Resistance of G. duodenalis to the most used drugs to treat giardiasis, metronidazole and albendazole, is a clinical issue of growing concern and yet unknown impact, respectively. In the search of new drugs, the completion of the Giardia genome project and the use of biochemical, molecular and bioinformatics tools allowed the identification of ligands/inhibitors for about one tenth of ≈150 potential drug targets in this parasite. Further, the synthesis of second generation nitroimidazoles and benzimidazoles along with high-throughput technologies have allowed not only to define overall mechanisms of resistance to metronidazole but to screen libraries of repurposed drugs and new pharmacophores, thereby increasing the known arsenal of anti-giardial compounds to some hundreds, with most demonstrating activity against metronidazole or albendazole-resistant Giardia. In particular, cysteine-modifying agents which include omeprazole, disulfiram, allicin and auranofin outstand due to their pleiotropic activity based on the extensive repertoire of thiol-containing proteins and the microaerophilic metabolism of this parasite. Other promising agents derived from higher organisms including phytochemicals, lactoferrin and propolis as well as probiotic bacteria/fungi have also demonstrated significant potential for therapeutic and prophylactic purposes in giardiasis. In this context the present chapter offers a comprehensive review of the current knowledge, including commonly prescribed drugs, causes of therapeutic failures, drug resistance mechanisms, strategies for the discovery of new agents and alternative drug therapies.

Piper Species: A Comprehensive Review on Their Phytochemistry, Biological Activities and Applications

Piper species are aromatic plants used as spices in the kitchen, but their secondary metabolites have also shown biological effects on human health. These plants are rich in essential oils, which can be found in their fruits, seeds, leaves, branches, roots and stems. Some Piper species have simple chemical profiles, while others, such as Piper nigrum, Piper betle, and Piper auritum, contain very diverse suites of secondary metabolites. In traditional medicine, Piper species have been used worldwide to treat several diseases such as urological problems, skin, liver and stomach ailments, for wound healing, and as antipyretic and anti-inflammatory agents. In addition, Piper species could be used as natural antioxidants and antimicrobial agents in food preservation. The phytochemicals and essential oils of Piper species have shown strong antioxidant activity, in comparison with synthetic antioxidants, and demonstrated antibacterial and antifungal activities against human pathogens. Moreover, Piper species possess therapeutic and preventive potential against several chronic disorders. Among the functional properties of Piper plants/extracts/active components the antiproliferative, anti-inflammatory, and neuropharmacological activities of the extracts and extract-derived bioactive constituents are thought to be key effects for the protection against chronic conditions, based on preclinical in vitro and in vivo studies, besides clinical studies. Habitats and cultivation of Piper species are also covered in this review. In this current work, available literature of chemical constituents of the essential oils Piper plants, their use in traditional medicine, their applications as a food preservative, their antiparasitic activities and other important biological activities are reviewed.

Limitations in the screening of potentially anti-cryptosporidial agents using laboratory rodents with gastric cryptosporidiosis

The emergence of cryptosporidiosis, a zoonotic disease of the gastrointestinal and respiratory tract caused by Cryptosporidium Tyzzer, 1907, triggered numerous screening studies of various compounds for potential anti-cryptosporidial activity, the majority of which proved ineffective. Extracts of Indonesian plants, Piper betle and Diospyros sumatrana, were tested for potential anti-cryptosporidial activity using Mastomys coucha (Smith), experimentally inoculated with Cryptosporidium proliferans Kváč, Havrdová, Hlásková, Daňková, Kanděra, Ježková, Vítovec, Sak, Ortega, Xiao, Modrý, Chelladurai, Prantlová et McEvoy, 2016. None of the plant extracts tested showed significant activity against cryptosporidia; however, the results indicate that the following issues should be addressed in similar experimental studies. The monitoring of oocyst shedding during the entire experimental trial, supplemented with histological examination of affected gastric tissue at the time of treatment termination, revealed that similar studies are generally unreliable if evaluations of drug efficacy are based exclusively on oocyst shedding. Moreover, the reduction of oocyst shedding did not guarantee the eradication of cryptosporidia in treated individuals. For treatment trials performed on experimentally inoculated laboratory rodents, only animals in the advanced phase of cryptosporidiosis should be used for the correct interpretation of pathological alterations observed in affected tissue. All the solvents used (methanol, methanol-tetrahydrofuran and dimethylsulfoxid) were shown to be suitable for these studies, i.e. they did not exhibit negative effects on the subjects. The halofuginone lactate, routinely administered in intestinal cryptosporidiosis in calves, was shown to be ineffective against gastric cryptosporidiosis in mice caused by C. proliferans. In contrast, the control application of extract Arabidopsis thaliana, from which we had expected a neutral effect, turned out to have some positive impact on affected gastric tissue.

The course of experimental giardiasis in Mongolian gerbil

Fifteen Mongolian gerbils were inoculated with 10 × 10⁶ viable trophozoites of Giardia intestinalis. Their faeces were examined daily by flotation method and the number of shed cysts was counted. Two animals (male and female) were euthanised at 4- to 5-day intervals (9, 14, 18 days post-infection (DPI)). The remaining nine gerbils were sacrificed and dissected at the end of the experiment (23 DPI). Their small intestinal tissues were processed for examination using histological sectioning and scanning electron microscopy and their complete blood count (CBC) was examined. The highest number of trophozoites at the total was observed in the duodenum in gerbils sacrificed on 14 DPI. Number of shed cysts was positively correlated with number of trophozoites rinsed from the intestine. Infected gerbils had lower body weight gain in comparison with control group and in three male gerbils; diarrhoea occurred during infection. Cyst shedding was negatively correlated with values of mean corpuscular haemoglobin concentration. Females showed another pattern in cyst shedding than males. This information needs to be taken into account while planning the experiments.