Medicinal plants as a source of antiparasitics: an overview of experimental studies

The Paradigm Shift of Using Natural Molecules Extracted from Northern Canada to Combat Malaria

Parasitic diseases, such as malaria, are an immense burden to many low- and middle-income countries. In 2022, 249 million cases and 608,000 deaths were reported by the World Health Organization for malaria alone. Climate change, conflict, humanitarian crises, resource constraints and diverse biological challenges threaten progress in the elimination of malaria. Undeniably, the lack of a commercialized vaccine and the spread of drug-resistant parasites beg the need for novel approaches to treat this infectious disease. Most approaches for the development of antimalarials to date take inspiration from tropical or sub-tropical environments; however, it is necessary to expand our search. In this review, we highlight the origin of antimalarial treatments and propose new insights in the search for developing novel antiparasitic treatments. Plants and microorganisms living in harsh and cold environments, such as those found in the largely unexploited Northern Canadian boreal forest, often demonstrate interesting properties that are not found in other environments. Most prominently, the essential oil of Rhododendron tomentosum spp. Subarcticum from Nunavik and mortiamides isolated from Mortierella species found in Nunavut have shown promising activity against Plasmodium falciparum.

Antiparasitic activity of the steroid-rich extract of Schima wallichii against poultry cestode

Background and Aim

Schima wallichii Korth., commonly known as the needlewood tree (family Theaceae) has therapeutic uses in traditional Mizo medicine for human helminthiasis and serves as a balm against ectoparasites in animals. Although the medicinal properties have been studied experimentally, its use as a traditional anthelmintic remains unexplored. This study aimed to analyze the chemical components and antiparasitic activity of S. wallichii.

Materials and Methods

The chemical analysis of S. wallichi bark extracts was conducted focusing on the secondary metabolites using petroleum ether, chloroform, and methanol. Gas chromatography-mass spectrometry (GC-MS) was used to identify the specific compounds. An anthelmintic susceptibility test was carried out against Raillietina tetragona, intestinal cestode parasite of fowl.

Results

The methanol extract yielded the highest concentrations of alkaloids, carbohydrates, glycosides, sterols, saponins, and tannins among all the extracts. Sterols were the most abundant compounds in all extracts, with flavonoids being absent. Secondary metabolites were largely absent in the petroleum ether and chloroform extracts. The GC-MS data identified cholest-22-ene-21-ol as the major steroid component. The cestode parasite was inhibited in a concentration-dependent manner by the plant extract. The plant extract's anthelmintic activity was evident through observable damage to the parasite's outer structure.

Conclusion

Phytosterols in S. wallichii bark are responsible for its anthelmintic properties. The mechanism and pharmaceutical properties of the anthelmintic molecule require further exploration.

Krameria lappacea root extract's anticoccidial properties and coordinated control of CD4 T cells for IL-10 production and antioxidant monitoring

Introduction

Recently, the use of botanicals as an alternative to coccidiostats has been an appealing approach for controlling coccidiosis. Therefore, this study was conducted to evaluate the potential role of aqueous methanolic extract (200 mg/kg) of Krameria lappacea (roots) (KLRE) against infection induced by Eimeria papillata.

Methods

A total of 25 male C57BL/6 mice were divided into five groups (I, II, III, IV, and V). On 1st day of the experiment, all groups except groups I (control) and II (non-infected-treated group with KLRE), were inoculated orally with 103 sporulated E. papillata oocysts. On the day of infection, group IV was treated with KLRE. Group V served as an infected-treated group and was treated with amprolium (coccidiostat).

Results

Treatment with extract and coccidiostat was continued for five consecutive days. While not reaching the efficacy level of the reference drug (amprolium), KLRE exhibited notable anticoccidial activity as assessed by key criteria, including oocyst suppression rate, total parasitic stages, and maintenance of nutrient homeostasis. The presence of phenolic and flavonoid compounds in KLRE is thought to be responsible for its positive effects. The Eimeria infection increased the oxidative damage in the jejunum. KLRE treatment significantly increased the activity of catalase and superoxide dismutase. On the contrary, KLRE decreased the level of malondialdehyde and nitric oxide. Moreover, KLRE treatment decreased macrophage infiltration in the mice jejunal tissue, as well as the extent of CD4 T cells and NFkB. E. papillata caused a state of systemic inflammatory response as revealed by the upregulation of inducible nitric oxide synthase (iNOs)-mRNA. Upon treatment with KLRE, the activity of iNOs was reduced from 3.63 to 1.46 fold. Moreover, KLRE was able to downregulate the expression of pro-inflammatory cytokines interferon-γ, nuclear factor kappa B, and interleukin-10 -mRNA by 1.63, 1.64, and 1.38 fold, respectively. Moreover, KLRE showed a significant reduction in the expression of IL-10 protein level from 104.27 ± 8.41 pg/ml to 62.18 ± 3.63 pg/ml.

Conclusion

Collectively, K. lappacea is a promising herbal medicine that could ameliorate the oxidative stress and inflammation of jejunum, induced by E. papillata infection in mice.

Britanin - a beacon of hope against gastrointestinal tumors?

Britanin is a bioactive sesquiterpene lactone known for its potent anti-inflammatory and anti-oxidant properties. It also exhibits significant anti-tumor activity, suppressing tumor growth in vitro and in vivo. The current body of research on Britanin includes thirty papers predominantly related to neoplasms, the majority of which are gastrointestinal tumors that have not been summarized before. To drive academic debate, the present paper reviews the available research on Britanin in gastrointestinal tumors. It also outlines novel research directions using data not directly concerned with the digestive system, but which could be adopted in future gastrointestinal research. Britanin was found to counteract liver, colorectal, pancreatic, and gastric tumors, by regulating proliferation, apoptosis, autophagy, immune response, migration, and angiogenesis. As confirmed in pancreatic, gastric, and liver cancer, its most commonly noted molecular effects include nuclear factor kappa B and B-cell lymphoma 2 downregulation, as well as Bcl-2-associated X protein upregulation. Moreover, it has been found to induce the Akt kinase and Forkhead box O1 axis, activate the AMP-activated protein kinase pathway, elevate interleukin-2 and peroxisome proliferator-activated receptor-γ levels, reduce interleukin-10, as well as downregulate matrix metalloproteinase-9, Twist family bHLH transcription factor 1, and cyclooxygenase-2. It also inhibits Myc-HIF1α interaction and programmed death ligand 1 transcription by interrupting the Ras/ RAF/MEK/ERK pathway and mTOR/P70S6K/4EBP1 signaling. Future research should aim to unravel the link between Britanin and acetylcholinesterase, mast cells, osteolysis, and ischemia, as compelling data have been provided by studies outside the gastrointestinal context. Since the cytotoxicity of Britanin on noncancerous cells is significantly lower than that on tumor cells, while still being effective against the latter, further in-depth studies with the use of animal models are merited. The compound exhibits pleiotropic biological activity and offers considerable promise as an anti-cancer agent, which may address the current paucity of treatment options and high mortality rate among patients with gastrointestinal tumors.

Opuntia Ficus-Indica Peel By-Product as a Natural Antioxidant Food Additive and Natural Anticoccidial Drug

The present study was carried out to valorize the Opuntia ficus-indica (OFI) by-products by extracting and identifying their biochemical compounds and evaluating their antioxidant potential by in vitro activities (DPPH radical and FRAP), as well as their capacity to stabilize margarine oxidation (rancimat test). In addition, their in vitro anticoccidial effect on the destruction of Eimeria oocysts isolated from naturally infected chickens was also targeted. Microwaves and response surface methodology tools were used to extract the maximum amount of phenolic compounds (42.05 ± 0.46 GAE mg/g DW of total phenolic compounds in 90 s at 400 watts). Moreover, the effect of extraction factors was also studied. Eight phenolic compounds, including isorhamnetin, dihydrokaempferol, and kaempferol-3-O-rutinoside, were identified. The findings confirmed that OFI peel extract has strong antioxidant activities (DPPH radical, ferric reducing power). The rancimat test shows that OFI peel extract improves margarine stability by 3.2 h. Moreover, it has a notable destruction rate of Eimeria oocysts (30.06 ± 0.51%, LC50: 60.53 ± 0.38 mg/mL). The present investigation offers promise for the reuse of food waste as natural margarine additives, protection of the environment, and substitution of anticoccidial synthetic treatments.