Bioassay-guided isolation and identification of active compounds from Fructus Arctii against Dactylogyrus intermedius (Monogenea) in goldfish (Carassius auratus)

Evaluation of phytochemicals and essential oils of Cupressus semprevirens in controlling cattle tick Rhipicephalus annulatus (Acari: Ixodidae)

BACKGROUND

Cupressus sempervirens is one of the conifer plants, that is used as an antimicrobial, antioxidant, anthelminthic, and many other health purposes. Rhipicephalus annulatus is one of the hard tick genera affecting the production and health of domestic animals in Egypt. Extensive use of chemical acaricides in the management of ticks caused acaricide resistance, environmental contamination, residues in meat and milk, and harmful effects on non-target species. For these reasons, there is an urgent need to create efficient, environmentally friendly acaricides. This work aimed to assay the essential oils and establish the phytochemical analysis of C. sempervirens extract, its effects against the semi-engorged females of R. annulatus, and discuss their possible control effects.

RESULTS

Using the spray-dip method by C. sempervirens ethanol, methanol, distal water, and chloroform extracts at different concentrations (10-50%), revealed a decrease in the percentage of mobile female R. annulatius ticks, and increased mortality proportionally with days after treatments (14 days) and/or extract concentrations (10-50%). The ethanol extracts showed their strongest acaricidal effect, where the female mortality percentage reached 100% using all concentrations at the end of the examined period. In addition, the estimated LC50 and LC95 of C. sempervirens ethanolic extract were recorded as the lowest values (12.2% and 17%, respectively) after 14 days of treatment compared with other extract types. The 50% ethanolic extract of C. sempervirens (the most effective one) revealed the presence of bioactive metabolites i.e. flavonoids, tannins, and carbohydrates (TSS). Also, its total antioxidant capacity and potential free-radical activity (DPPH) were estimated. Using GC-MS, the extracted oil revealed the presence of four major compounds i.e., Eicosapentaenoic acid (50.85%), 10,12-Docosadiynedioic acid (27.58%),10-Undecynoic acid (14.28%) and Palmitic acid (5.42%). The efficiency of all phytochemicals and essential oils was discussed in the current study.

CONCLUSION

The phytochemicals and essential oils found in C. sempervirens could enhance our understanding and help in developing potential strategies for controlling ticks in general and for R. annulatus, in particular, using environmentally friendly agents.

In Vitro and in Vivo Antiparasitic Efficacy of Aqueous Mahua Oil Cake Extract Against Argulus foliaceus Infestation in Cyprinus carpio (Linneaus, 1758)

PURPOSE

The present study aims to elucidate the efficacy of mahua oil cake extract against argulosis infestation in common carp.

METHODS

Aqueous extract of mahua oil cake was prepared using different methods and the best extract was chosen based on its saponin content. Based on the above findings, the in vitro AE (Antiparasitic efficacy) was calculated for Argulus foliaceus. The parasite was exposed to various concentrations of the extract viz., 15, 17, 19, 21, 23 and 25 mg l-1 for 36 h. After the in vitro test, the next experiment was done to evaluate the toxicity of the extract for common carp. Following the assessment of in vitro AE and extract toxicity the Argulus sp. infected common carp were exposed five concentrations of extract [T1: LC50/5; T2: LC50/2.5; T3: in vitro EC50 value (16.45 mg l-1); T4: 21 mg l-1 and Control]. The experiment was conducted for 96 h, during which parasite mortality was recorded, and AE was calculated.

RESULTS

Under the in vitro test, 100% AE was achieved at 23 and 25 mg l-1 and EC50 was found to be 16.45 mg l-1. The 96 h LC50 value for common carp was 26.79 mg l-1. The extract showed 100% AE in the T3 and T4 groups containing Argulus infected common carp with an exposure period of 96 h and was significantly higher (p < 0.05) than control and other treatment groups.

CONCLUSION

Therefore, it can be concluded that the aqueous mahua oil cake extract has a therapeutic effect against the argulosis infection in common carp at a concentration of 16.45 mg l-1.

Elucidating the effect of dietary neem (Azadirachta indica) on growth performance, haemato-biochemical, immunonological response, and anti-pathogenic capacity of Nile tilapia juveniles

This investigation attempts to evaluate the effect of diet additives via aqueous or ethanolic herbal extracts from Azadirachta indica leaves on Nile tilapia, Oreochromis niloticus. Five dietary categories were assigned to the fish: the first category (N1, with no extract) was kept under control conditions; two categories contained aqueous extract (N2 (1.0 g/kg) and N3 (2.0 g/kg); and two categories contained ethanolic extract, N4 (1.0 g/kg) and N5 (2.0 g/kg), with each group being fed for 60 days. After the feeding trial, Aeromonas hydrophila was injected intraperitoneally into fish for 14 days; fish mortality was recorded during this period. The results showed that the fish-fed dietary A. indica significantly improved growth performance and intestinal health (digestive enzymes and intestinal morphology), especially in the N4 and N5 categories. However, N4 and N5 categories demonstrated a significant decrease in AST and ALT activities and an increase in total protein, serum albumin, globulin, growth hormone (GH), leptin hormone (LEP), hemoglobin, white blood cells, and hematocrit (P  < 0.05) in comparison with the control category (N1). Compared to the control category, the N4 and N5 categories have revealed a significant reduction in MDA activity and improvements in immunological activities (lysozyme, complement C3, and nitric oxide) and antioxidant enzymes (CAT, SOD, and GPX). Moreover, in tilapia-fed A. indica, the expression of IL-8, IL-1β, and Nf-κb genes was downregulated partially in the N4 and N5 categories than the control category. In contrast, the lysozyme, C3, GPX, and CAT genes were upregulated partially at N4 and N5 compared to the control category. Following the bacterial challenge, fish in the N4 and N5 categories also displayed the lowest fish mortality compared to the control category. The ethanolic extract displayed a more potent resistance against the parasite Cichlidogyrus tilapia in vitro than the aqueous and control categories, partially at 2 g/L. According to these findings, an ethanolic neem extract (2.0 g/kg feed) activates the immune system and antioxidant response in Nile tilapia fingerlings, improving growth and fish resistance to parasitic and bacterial infections.

Two new aryltetralin-type lignans from Camellia oleifera husk

Two new aryltetralin-type lignans (1-2) were isolated from the dichloromethane fraction of 95% ethanol extract of Camellia oleifera fruit husk. Their structures were elucidated on the basis of spectroscopic analysis, and the absolute configurations of compounds 1-2 were determined by the comparison of measured ECD curves with the quantum chemical calculated ones. The new compounds were tested for their antioxidant activities and cytotoxicity against three human cancer cell lines (Huh-7, H460 and MCF-7). While compounds 1 and 2 only showed slight DPPH radical scavenging activities with the IC50 values of 38.68 ± 5.02 and 56.62 ± 1.49 μM, respectively.

Synthesis and anti-parasites efficacy of coumarin derivatives against Dactylogyrus intermedius

Dactylogyrus is one of the most common parasitic diseases in fish and causes huge losses to the aquaculture industry. With the advantages of safety, low toxicity and easy degradation, plant-derived drugs are ideal for the creation of green aquatic ingredients. The use of plant-derived drugs in aquaculture is limited by their low content and high processing costs, which is a challenge that can be solved by the chemical synthesis of plant-derived drugs. Eleven new coumarin derivatives were synthesized and assessed for their anthelmintic activity in this study. Among them, the derivative 7-((1-tosyl-1H-1,2,3-triazol-4-yl)methoxy)-2H-chromen-2-one (N11) has good anthelmintic activity and its mean anthelmintic efficacy against D. intermedius at a concentration of 10 μM reached 99.84%, which is even better than the anthelmintic activity of the positive control mebendazole. Further studies showed that N11 had concentration values of 3.31 and 1.94 μM for 50% maximal effect (EC50 ) against D. intermedius at 24 and 48 h, respectively. Furthermore, scanning electron microscopy revealed that N11 caused damage to D. intermedius. What is more noteworthy is that a substantial reduction in the ATP content of the parasite was observed following in vitro and in vivo administration of N11. Moreover, it was also found that N11 was able to inhibit the horizontal transmission of D. intermedius. Furthermore, real-time quantitative PCR analysis was utilized to determine the expression profile of genes associated with anti-inflammatory cytokines (IL-10, TGF-β and IL-4) in goldfish. In all examined organs, it was observed that the expression of anti-inflammatory cytokines increased subsequent to treatment with N11, according to the results. Thus, these results all suggest that N11 possesses good anthelmintic activity and is a potentially effective agent for the control of D. intermedius.

Prevalence of cattle ixodid ticks and acaricides efficacy evaluation in Amibara district of Afar Region, Ethiopia

A cross sectional and randomized controlled trial study was conducted starting from July 2021 to July 2022 to determine the prevalence of ixodid ticks, and evaluate the efficacy of commonly used acaricides (amitraz 12.5% and diazinon 60%) in vitro and in vivo on cattle ticks in Amibara district. A total of 372 cattle were visited randomly from six kebeles of the district which were selected based on their livestock population. A total of 4330 adult ticks were collected and identified to the species level with stereomicroscope. For the invitro acaricide efficacy test, 90 engorged female ticks were collected from infested herds and grouped into three, each group having ten engorged ticks; two groups for the two test acaricides and the third groups were control to evaluate these acaricides in the laboratory. All the groups were replicated three times and incubated for seven days with similar temperature and humidity. Thirty-six infested cattle were selected and again grouped into three randomly, 12 each for the invivo test. The first groups of animals were sprayed with amitraz, the second with diazinon and the third groups were left untreated. Ticks were counted and recorded before, day 3, day 7, day 14 and day 21 of spraying. A total of 360 (96.7%) of the visited cattle were infested with ticks. Amblyomma. Rhipicephallus, Hyalomma and Bophillus were the genera of ticks identified with a prevalence of 44.9%, 41.4%, 7.5% and 6.2% respectively. A total of 15 species of ixodid ticks were identified from which Rhipicephallus pulchellus (39.86%) was dominant followed by Amblyomma lepidum (26.65%) and Amblyomma gemma (14.36%). Diazinon 60% EC and amitraz 12.5% were significantly inhibited the egg laying ability of engorged ticks' in vitro with percent inhibition of 100% and 99.1% respectively. On live animal, both acaricides showed statistically significant difference from the control group (p- value <0.05) with maximum 97.37% (amitraz) and 93.33% (diazinon) at day 7 and minimum 73.3% (amitraz) and 73.7% (diazinon) efficacy. However, there was no statistically significant difference on egg laying inhibition and tick count reduction between the two acaricides (p-value >0.05). Therefore, awareness should be created about the high prevalence as well as the application, dosage and dilution of the acaricides to pastoralists, community animal health workers and para veterinarians in the study area. Cattle owners, veterinarians and concerned government officials should address infested herds with manufacturer recommended dosage of these acaricides to control the tick infestation.

A comparison between the effectiveness of the fungi Beauveria bassiana and Metarhizium anisopliae for the control of Argas persicus with the emphasis of histopathological changes in the integument

Argas persicus is an important ectoparasite of domestic fowl that causes heavy economic losses to the poultry industry. The present study was carried out to compare and assess the effects induced by spraying the fungi Beauveria bassiana and Metarhizium anisopliae separately, on the mobility and viability of semifed adult A. persicus, also to follow the histopathological effect induced by a selected concentration of 10¹⁰ conidia/ml of B. bassiana on the integument. Biological studies revealed a more or less similar pattern of response in adults treated with either of the two fungi (Increasing concentration resulting in more death along with examined period). As the estimated LC50 and LC95 of B. bassiana were recorded 5 × 10⁹ and 4.6 × 10¹² conidia/ml, respectively, and for M. anisopliae were 3 × 10¹¹ and 2.7 × 10¹⁶ conidia/ml respectively, the fungus B. bassiana was more efficient than M. anisopliae when applied at the same concentrations. The study revealed that spraying of Beauveria at 10¹² conidia/ml is sufficient to control A. persicus as it recorded 100% efficacy, so it might be selected to be the effective dose. Histological investigation of the integument treated with B. bassiana revealed the dispersal of the hyphal network on the after 11 days of treatment, accompanied by other changes. Results from our study verify the susceptibility of A. persicus to the pathogenic effect induced by spraying B. bassiana, which is sufficient for its control with the recording better results.

Arctigenin: pharmacology, total synthesis, and progress in structure modification

Arctium lappa L. is a prevalent medicinal herb and a health supplement that is commonly used in Asia. Over the last few decades, the bioactive component arctigenin has attracted the attention of researchers because of its anti-inflammatory, antioxidant, immunomodulatory, multiple sclerosis fighting, antitumor, and anti-leukemia properties. After summarising the research and literature on arctigenin, this study outlines the current status of research on pharmacological activity, total synthesis, and structural modification of arctigenin. The purpose of this study is to assist academics in obtaining a more comprehensive understanding of the research progress on arctigenin and to provide constructive suggestions for further investigation of this useful molecule.

Phytogenic Substances: A Promising Approach Towards Sustainable Aquaculture Industry

The aquaculture industry has shown rapid growth over the last three decades, especially with improving the farming systems. However, the rapid expansion and intensification practices in the aquaculture sector have been marred by increased stress levels and disease outbreaks, and subsequently, high fish mortality. Excessive use of veterinary drugs and antibiotics in aquaculture poses a great threat to human and aquatic animals' health, as well as to the biosystem. Furthermore, exposure to various pollutants such as industrial effluents and agricultural pesticides may cause devastating toxicological aspects of fish and adversely affect their health and growth. Besides, with a growing world population, there is a growing interest in intensifying aquaculture production to meet the global demand for nutritional security needs. Uncontrolled intensification of aquaculture production makes aquatic animals both vulnerable to, and potential sources of a wide range of hazards include pathogen transmission, disease outbreak, immunosuppression, impaired growth performance, malnutrition, foodborne illness, and high mortality. Plant-derived compounds are generally recognized as safe for fish, humans, and the environment and possess great potential as functional ingredients to be applied in aquaculture for several purposes. Phytogenic additives comprise a wide variety of medicinal plants and their bioactive compounds with multiple biological functions. The use of phytogenic compounds can open a promising approach towards enhancing the health status of aquatic animals. However, further in-vivo trials are necessary under favorable conditions with controlled amounts of identified bioactive compounds along with toxicity testing for fish safety towards a realistic evaluation of the tested substance efficacy.

Growth Performance, Immune Response, Antioxidative Status, and Antiparasitic and Antibacterial Capacity of the Nile Tilapia (Oreochromis niloticus) After Dietary Supplementation With Bottle Gourd (Lagenaria siceraria, Molina) Seed Powder

Medicinal plants are a potential safe source of bioactive compounds. Fish diet supplemented with the medicinal plant bottle gourd (Lagenaria siceraria) seed powder was evaluated in this study for the potential effect on growth performance, antioxidative status, immunological response, and resistance to infectious pathogens in the Nile tilapia (Oreochromis niloticus). Nile tilapia fingerlings with mean weight ( ± SD)= (25.64 ± 0.17 g), were fed four L. siceraria seed supplemented diets (LSSD) at 0.0, 1, 2, and 3% for 60 days. Specimens were then challenged with the bacterium Aeromonas hydrophila for 10 days. Also, three different concentrations (2.5, 5, and 10 ml/L) of Lagenaria siceraria ethanolic extract (LSEE) were tested for their antibacterial and antiparasitic efficacy on four selected bacterial and one parasitic species. All parameters’ values generally improved with elevating the content of the L. siceraria seed powder in the diet. Dietary administration of LSSD-3% enabled significant (P &lt; 0.05) higher growth performance, and feed utilization efficiency. It reduced the mortality induced by A. hydrophila infection, increased crude protein content in the fish body and exhibited the highest in vitro antibacterial and antiparasitic efficiency. RBCs, WBCs, Hb, PCV, MCV, MCH, and total serum protein values in pre- and post-challenge groups were significantly higher (P &lt; 0.05) in the LSSD-3% group. While MCHC, ALT, AST and glucose levels were significantly lower (P &lt; 0.05) than those of the other groups. Lysozyme and antioxidant enzyme activities in pre- and post-challenge groups were also higher (P &lt; 0.05) in the LSSD-3% group compared to the other groups. LSEE provided good efficacy against Gram-negative bacterial strains, mild efficacy against Gram-positive bacterial strains, and an antagonistic effect on the parasite Cichlidogyrus Tilapiae. The 10 ml/L concentration was the most effective against the pathogens followed by the 5 ml/L concentration and then 2.5 ml/L. Our findings suggest the feasibility of supplementation of Nile tilapia (O. niloticus) diet with L. siceraria seed powder by 3% to improve the growth performance, immunity, and vital parameters.

Antiparasitic potentiality of ethanol and methanol extracts of Azadirachta indica leaf for eggs and copepodid stage of Argulus japonicus: in vitro study

In the present study, eggs and copepodid stages of Argulus japonicus were treated with ethanol and methanol extract of Azadirachta indica (neem) leaf and its antiparasitic efficacy (AE %) was determined. The experiments were performed in triplicate along with the positive (2% DMSO) and negative (without DMSO and extract) control groups. The reduced cumulative hatching percentage of eggs by 13% (in ethanolic) and 17% (in methanolic) extract of neem leaf at 1.5 g L^-1 was obtained during 15-day exposure compared to the control group showing 70-85% eggs hatching. The AE of 100% for ethanolic and 91.66% for methanolic extract against the copepodid stage was found at 1.25 and 1.5 g L^-1 respectively in 6 h. The histological analysis of the eggs showed the undifferentiated decaying mass of cells with extensively damaged eggs when treated with ethanolic extract of neem leaf. Further, severe degeneration in the branchial region, digestive tract and eye cells was observed in the copepodids treated with ethanol extract than the methanol extract. The terpenoids a potential antiparasitic compound of ethanolic extract produced more AE than the methanolic extract. Thus, the ethanolic extract of neem leaf can be potentially utilized as a natural parasiticide to disrupt the egg and other life phases of A. japonicus.

Optimisation of the Conversion and Extraction of Arctigenin From Fructus arctii Into Arctiin Using Fungi

Fructus arctii is commonly used in Chinese medicine, and arctiin and arctigenin are its main active ingredients. Arctiin has low bioavailability in the human body and needs to be converted into arctigenin by intestinal microbes before it can be absorbed into the blood. Arctigenin has antiviral, anti-inflammatory, and anti-tumour effects and its development has important value. In this study, we used external microbial fermentation with Aspergillus awamori and Trichoderma reesei to process and convert arctiin from F. arctii powder into arctigenin, hence increasing its bioavailability. We developed a fermentation process by optimising the carbon and nitrogen source/ratio, fermentation time, pH, liquid volume, inoculation volume, and substrate solid-liquid ratio. This allowed for an arctiin conversion rate of 99.84%, and the dissolution rate of the final product was 95.74%, with a loss rate as low as 4.26%. After the fermentation of F. arctii powder, the average yield of arctigenin is 19.51 mg/g. Crude fermented F. arctii extract was purified by silica gel column chromatography, and we observed an arctigenin purity of 99.33%. Our technique effectively converts arctiin and extracts arctigenin from F. arctii and provides a solid basis for further development and industrialisation.

Proteome interrogation using gold nanoprobes to identify targets of arctigenin in fish parasites

Gold nanoparticles (GNPs) are one of the most widely used nanomaterials in various fields. Especially, the unique chemical and physical properties make them as the promising candidates in drug target identification, unfortunately, little is known about their application in parasites. In this paper, GNPs were employed as new solid support to identify drug targets of natural bioactive compound arctigenin (ARG) against fish monogenean parasite Gyrodactylus kobayashi. Before target identification, GNPs with ARG on the surface showed the ability to enter the live parasites even the nucleus or mitochondria, which made the bound compounds capable of contacting directly with target proteins located anywhere of the parasites. At the same time, chemically modified compound remained the anthelminthic efficacy against G. kobayashii. The above results both provide assurance on the reliability of using GNPs for drug target-binding specificity. Subsequently, by interrogating the cellular proteome in parasite lysate, myosin-2 and UNC-89 were identified as the potential direct target proteins of ARG in G. kobayashii. Moreover, results of RNA-seq transcriptomics and iTRAQ proteomics indicated that myosin-2 expressions were down-regulated after ARG bath treatment both in transcript and protein levels, but for UNC-89, only in mRNA level. Myosin-2 is an important structural muscle protein expressed in helminth tegument and its identification as our target will enable further inhibitor optimization towards future drug discovery. Furthermore, our findings demonstrate the power of GNPs to be readily applied to other parasite drugs of unknown targets, facilitating more broadly therapeutic drug design in any pathogen or disease model.

Antiparasitic activity in Asteraceae with special attention to ethnobotanical use by the tribes of Odisha, India

The purpose of this review is to survey the antiparasitic plants of the Asteraceae family and their applicability in the treatment of parasites. This review is divided into three major parts: (a) literature on traditional uses of Asteraceae plants for the treatment of parasites; (b) description of the major classes of chemical compounds from Asteraceae and their antiparasitic effects; and (c) antiparasitic activity with special reference to flavonoids and terpenoids. This review provides detailed information on the reported Asteraceae plant extracts found throughout the world and on isolated secondary metabolites that can inhibit protozoan parasites such as Plasmodium, Trypanosoma, Leishmania, and intestinal worms. Additionally, special attention is given to the Asteraceae plants of Odisha, used by the tribes of the area as antiparasitics. These plants are compared to the same plants used traditionally in other regions. Finally, we provide information on which plants identified in Odisha, India and related compounds show promise for the development of new drugs against parasitic diseases. For most of the plants discussed in this review, the active compounds still need to be isolated and tested further.

Anthelmintic efficacy of cinnamaldehyde and cinnamic acid from cortex cinnamon essential oil against Dactylogyrus intermedius

Utilization of chemical pesticide to control monogenean diseases is often restricted in many countries due to the development of pesticide resistance and concerns of chemical residues and environmental contamination. Thus, the use of antiparasitic agents from plants has been explored as a possible way for controlling monogenean infections. Extracts from Cinnamomum cassia were investigated under in vivo conditions against Dactylogyrus intermedius in goldfish. The two bioactive compounds, cinnamaldehyde and cinnamic acid, were identified using nuclear magnetic resonance and electrospray ionization mass spectrometry. The 48 h median effective concentrations (EC(50)) for these compounds against D. intermedius were 0·57 and 6·32 mg L(-1), respectively. The LD(50) of cinnamaldehyde and cinnamic acid were 13·34 and 59·66 mg L(-1) to goldfish in 48 h acute toxicity tests, respectively. These data confirm that cinnamaldehyde is effective against D. intermedius, and the cinnamaldehyde exhibits potential for the development of a candidate antiparasitic agent.

Short-term exposure to L-type calcium channel blocker, verapamil, alters the expression pattern of calcium-binding proteins in the brain of goldfish, Carassius auratus

The influx of calcium ions (Ca(2+)) is responsible for various physiological events including neurotransmitter release and synaptic modulation. The L-type voltage dependent calcium channels (L-type VDCCs) transport Ca(2+) across the membrane. Calcium-binding proteins (CaBPs) bind free cytosolic Ca(2+) and prevent excitotoxicity caused by sudden increase in cytoplasmic Ca(2+). The present study was aimed to understand the regulation of expression of neuronal CaBPs, namely, calretinin (CR) and parvalbumin (PV) following blockade of L-type VDCCs in the CNS of Carassius auratus. Verapamil (VRP), a potent L-type VDCC blocker, selectively blocks Ca(2+) entry at the plasma membrane level. VRP present in the aquatic environment at a very low residual concentration has shown ecotoxicological effects on aquatic animals. Following acute exposure for 96h, median lethal concentration (LC50) for VRP was found to be 1.22mg/L for goldfish. At various doses of VRP, the behavioral alterations were observed in the form of respiratory difficulty and loss of body balance confirming the cardiovascular toxicity caused by VRP at higher doses. In addition to affecting the cardiovascular system, VRP also showed effects on the nervous system in the form of altered expression of PV. When compared with controls, the pattern of CR expression did not show any variations, while PV expression showed significant alterations in few neuronal populations such as the pretectal nucleus, inferior lobes, and the rostral corpus cerebellum. Our result suggests possible regulatory effect of calcium channel blockers on the expression of PV.

Dactylogyrus intermedius parasitism enhances Flavobacterium columnare invasion and alters immune-related gene expression in Carassius auratus

The monogenean Dactylogyrus intermedius and the bacterium Flavobacterium columnare are 2 common pathogens in aquaculture. The objective of the present study was to examine the effect of prior parasitism by D. intermedius on the susceptibility of goldfish to F. columnare and to explore the potential immune mechanisms related to the parasite infection. A F. columnare challenge trial was conducted between D. intermedius-parasitized and non-parasitized goldfish. The F. columnare load in gill, kidney, spleen and liver were compared. The expression of immune-related genes (IL-1β2, TNF-α1, TGF-β, iNOS-a, C3 and Lyz) in gill and kidney of D. intermedius-only infected and uninfected control fish were evaluated. D. intermedius-parasitized goldfish exhibited higher mortality and significantly higher loads (3051 to 537,379 genome equivalents [GEs] mg(-1)) of F. columnare, which were 1.13 to 50.82-fold higher than non-parasitized fish (389 to 17,829 GEs mg(-1)). Furthermore, the immune genes IL-1β2, TNF-α1, iNOS-a and Lyz were up-regulated while the TGF-β and C3 were down-regulated in the gill and kidney of parasite-infected fish compared to the non-parasitized controls. The down-regulation TGF-β and C3 was especially noteworthy, as this might indicate the suppression of the host immune functions due to the parasitism by D. intermedius. Taken together, these data demonstrate that parasite infection can enhance bacterial invasion and presents a hypothesis, based on gene expression data, that modulation of host immune response could play a role.

In vitro and in vivo assessment of the effect of antiprotozoal compounds isolated from Psoralea corylifolia against Ichthyophthirius multifiliis in fish

Ichthyophthirius multifiliis, an external fish parasite, often causes significant economic damage to the aquaculture industry. Since the use of malachite green was banned, the search of alternative substance to control I. multifiliis infections becomes stringent. In present study, in vitro and in vivo anti-ich efficacies of isopsoralen and psoralidin, two active compounds isolated from methanol extract of Psoralea corylifolia by bioassay-guided fractionation based on the efficacy of anti-ich encysted tomonts, were evaluated. In vitro antiprotozoal efficacy of psoralidin is much better than that of isopsoralen. Psoralidin can kill all theronts at concentrations of 0.8 mg/L or more during 4 h exposure; and terminate reproduction of I. multifiliis post 6 h exposure of protomonts to 0.9 mg/L and encysted tomonts to 1.2 mg/L. In vivo trials showed that 5 h exposure of infected fish to 2.5 mg/L of psoralidin significantly reduced the number of theronts released from tomonts. Furthermore, we observed that a part of protomonts, collected from infected fish post treatment, presented characteristic morphological changes of apoptosis after staining with Annexin V-EGFP/propidium iodide, indicating the possible mechanism of psoralidin against I. multifiliis trophont in situ. On the basis of these results, psoralidin can be used as a potential lead compound for the development of commercial drug against I. multifiliis.

Anthelmintic activity of ginger, curcumin, and praziquentel against Raillietina cesticillus (in vitro and in vivo)

This work evaluates the anthelminitic activity of ginger and curcumin on the cestode Raillietina cesticillus. Live parasites were collected from intestine of naturally infected chickens in PBS 0.9 % and then incubated at 37 °C in media containing ginger extract at three different concentrations (125, 250, and 500 mg); every concentration was dissolved in 10 ml media. The curcumin extract was used at three different concentrations (250, 500, and 1000 mg); each was dissolved in 10 ml media. Praziquantel at a concentration of 600 mg was added to 10 ml media. A control one without extract was reported. Regression of worms increased gradually in all concentrations. At 500 mg ginger (50 ± 0 %), worms were regressed at 48 h post-exposure (h.p.e.). Also (50 ± 1.8 %), worms were regressed at 1000 mg curcumin at the same time. On the other hand, praziquantel showed the highest regression (65 ± 2.3 %). The extract efficacy was exhibit as concentration-time-dependent mainly at higher concentrations used after 48 h. In vivo effects of ginger and curcumin were lower than those in vitro.

In vitro immunocompetence of two compounds isolated from Polygala tenuifolia and development of resistance against grass carp reovirus (GCRV) and Dactylogyrus intermedius in respective host

The present study was undertaken to isolate some compounds from methanol extract of Polygala tenuifolia and evaluate their immunostimulatory properties and antiviral activity using grass carp Ctenopharyngodon idella kidney (CIK) cells and GCRV. By applying insecticidal bioassay-guided, chromatography techniques and successive recrystallization, two purified compounds were obtained. The changes of expression of selected immune genes (Mx1, IL-1β, TNFα, MyD88 and IgM) in C. idella kidney cell lines were evaluated after exposure to these isolated compounds. The results showed that compound 1 and 2 up-regulated to varying degrees of Mx1, IL-1β, TNFα, and MyD88 in C. idella kidney cells. WST-8 kit assay verified the two compounds has no toxic effects on CIK cell, and furthermore, have in vitro antivirus activity. Especially, that there is keeping 79% cell viability when exposure to compound 2 (100 mg L(-1)). According to in vivo insecticidal assays against Dactylogyrus intermedius, compound 2 exhibited higher efficacy than compound 1, which was found to be 87.2% effective at the concentrations of 5 mg L(-1) and safe to goldfish (Carassius auratus). Besides, the purified compounds were identified by spectral data as: (1) 1,5-Anhydro-D-glucitol and (2) 3,4,5-trimethoxy cinnamic acid. Overall, the results indicate that bath administration of these compounds modulates the immune related genes in C. idella kidney cells and to some extent, eliminate the virus and parasitic infections.

Arctigenin but not arctiin acts as the major effective constituent of Arctium lappa L. fruit for attenuating colonic inflammatory response induced by dextran sulfate sodium in mice

The crude powder of the fruit of Arctium lappa L. (ALF) has previously been reported to attenuate experimental colitis in mice. But, its main effective ingredient and underlying mechanisms remain to be identified. In this study, ALF was extracted with ethanol, and then successively fractionated into petroleum ether, ethyl acetate, n-butanol and water fraction. Experimental colitis was induced by dextran sulfate sodium (DSS) in mice. Among the four fractions of ALF, the ethyl acetate fraction showed the most significant inhibition of DSS-induced colitis in mice. The comparative studies of arctigenin and arctiin (the two main ingredients of ethyl acetate fraction) indicated that arctigenin rather than arctiin could reduce the loss of body weight, disease activity index and histological damage in the colon. Arctigenin markedly recovered the loss of intestinal epithelial cells (E-cadherin-positive cells) and decreased the infiltration of neutrophils (MPO-positive cells) and macrophages (CD68-positive cells). Arctigenin could down-regulate the expressions of TNF-α, IL-6, MIP-2, MCP-1, MAdCAM-1, ICAM-1 and VCAM-1 at both protein and mRNA levels in colonic tissues. Also, it markedly decreased the MDA level, but increased SOD activity and the GSH level. Of note, the efficacy of arctigenin was comparable or even superior to that of the positive control mesalazine. Moreover, it significantly suppressed the phosphorylation of MAPKs and the activation of NF-κB, including phosphorylation of IκBα and p65, p65 translocation and DNA binding activity. In conclusion, arctigenin but not arctiin is the main active ingredient of ALF for attenuating colitis via down-regulating the activation of MAPK and NF-κB pathways.

Screening Medicinal Plants for Use against Dactylogyrus intermedius (Monogenea) Infection in Goldfish

Abstract Methanol extracts of 24 traditional medicinal plants with potential anthelmintic activity against Dactylogyrus intermedius (Monogenea) in Goldfish Carassius auratus were investigated. Abrus cantoniensis, Citrus medica, Dioscorea collettii, and Polygonum multiflorum exhibited 100% activity and were selected for further evaluation by applying five solvents (petroleum ether, chloroform, ethyl acetate, methanol, and water) for the extraction of the samples, followed by an in vivo bioassay. Among the plants tested, water, methanol, and ethyl-acetate extracts of P. multiflorum showed the highest efficacies; EC50 values (median concentration that results in 50% of its maximal effect) were 1.9, 5.4, and 9.1 mg/L, respectively, and extracts showed 100% efficacy against Dactylogyrus intermedius at 100, 12.5, and 25 mg/L. This was followed by ethyl-acetate, chloroform, and methanol extracts of Dioscorea collettii, which demonstrated 100% efficacy at 80, 80, and 120 mg/L and had EC50 values of 19.7, 27.1, and 37.8 mg/L, respectively, after 48 h of exposure. Chloroform and ethyl-acetate extracts of C. medica, which exhibited 100% efficacy against Dactylogyrus intermedius at 100 and 125 mg/L, revealed similar activity and had EC50 values of 58.7 and 51.3 mg/L, respectively. The ethyl-acetate and methanol extracts of A. cantoniensis exhibited the lowest activity and had EC50 values of 279.4 and 64.3 mg/L. Acute toxicities of these active extracts were investigated on Goldfish for 48 h. The findings indicated that extracts of the four plants can be developed as a preferred natural antiparasitic for the control of D. intermedius. Received June 15, 2013; accepted February 11, 2014.

Effects of praziquantel and sanguinarine on expression of immune genes and susceptibility to Aeromonas hydrophila in goldfish (Carassius auratus) infected with Dactylogyrus intermedius

Praziquantel and sanguinarine have been demonstrated positive therapeutic effects on monogenean Dactylogyrus intermedius; however, few studies have considered the post impacts of these antiparasitic chemicals on host after repelling the parasites. The changes of expression of selected immune genes (CCL-1, CXCL-8, IL-1β-1, IL-1β-2, TNFα-1, TNFα-2 and TGF-β) in gill, kidney and spleen and bacterial loads of Aeromonas hydrophila in gill, kidney, spleen and liver following bath administration of these antiparasitic chemicals were evaluated. The results showed that praziquantel and sanguinarine up-regulated to varying degrees of CXCL-8, IL-1β-1, IL-1β-2, TNFα-1 and TNFα-2 in gill, kidney and spleen. They both decreased the CCL-1 expression in gill while increased it in kidney and spleen. However, in all the tested tissues, the expression of TGF-β decreased in praziquantel treated goldfish whereas that increased in sanguinarine treated goldfish. The A. hydrophila challenge test showed that the praziquantel treatment enhanced the susceptibility to A. hydrophila while sanguinarine treatment decreased the susceptibility, as compared with the non-treated group. Overall, the results indicate that bath administration of praziquantel and sanguinarine modulates the immune related genes in goldfish and these may, to some extent, affect their ability to resist bacterial pathogens.

Screening of plant extracts for anthelmintic activity against Dactylogyrus intermedius (Monogenea) in goldfish (Carassius auratus)

With the aim of finding natural anthelmintic agents against Dactylogyrus intermedius (Monogenea) in goldfish (Carassius auratus), 26 plants were screened for antiparasitic properties using in vivo anthelmintic efficacy assay. The results showed that Caesalpinia sappan, Lysima chiachristinae, Cuscuta chinensis, Artemisia argyi, and Eupatorium fortunei were found to have 100% anthelmintic efficacy at 125, 150, 225, 300, and 500 mg L(-1) after 48 h of exposure. Crude extract of the five plants were further partitioned with petroleum ether, chloroform, ethyl acetate, methanol, and water to obtain anthelmintically active fractions with various polarity. Among these fractions tested, the ethyl acetate extract of L. chiachristinae was found to be the most effective with a 50% effective concentration (EC50) value of 5.1 mg/L after 48 h of exposure. This was followed by ethyl acetate extract of C. chinensis (48 h-EC50 = 8.5 mg L(-1)), chloroform extracts of C. sappan (48 h-EC50 = 15.6 mg L(-1)), methanol extract of C. chinensis (48 h-EC50 = 15.9 mg L(-1)), and chloroform and petroleum ether extract of L. chiachristinae (EC50 values of 17.2 and 21.1 mg/L, respectively), suggesting that these plants, as well as the active fractions, provide potential sources of botanic drugs for the control of D. intermedius in aquaculture.

Antiparasitic efficacy of piperine against Argulus spp. on Carassius auratus (Linn. 1758): in vitro and in vivo study

Argulus are common aquatic ectoparasites that create one of the major threats to aquaculture due to absence of suitable therapy. Piperine, a bioactive component of Piper longum, has medicinal properties and acts as anti-inflammatory, antibacterial, and antifungal, considering eco-friendliness and cost-effectiveness. The present study aimed to evaluate antiparasitic effect of piperine against an ectoparasite Argulus spp. on Carassius auratus. Artificial Argulus infection was carried out by cohabitation method, and the fishes were selected for in vivo study when intensity of Argulus infestation was observed to be 15-20 Argulus per fish. In vitro and in vivo studies were performed at different concentration 1.0 (T (1)), 3.0 (T (2)), 5.0 (T (3)), 7.0 (T (4)), and 9.0 mg l(-1) (T (5)) of piperine solution to treat Argulus for 3 and 72 h, respectively. The acute toxicity test for piperine EC 97 % against goldfish was performed for 96 h. The 96 h median lethal concentration (LC(50)) for piperine was found to be 52.64 mg l(-1). In vitro effect of piperine solution led to 100 % mortality of Argulus at 9.0 mg l(-1) in 3 h whereas, under in vivo test, the 100 % antiparasitic efficacy of piperine solution was found at 9.0 mg l(-1) in 48 h. The EC(50) for 48 h was 9.0 mg l(-1), and thus, therapeutic index is 5.8. The results revealed that piperine at a concentration of 9.0 mg l(-1) can be used as a potential natural agent for controlling Argulus parasite.

Antiprotozoal activity of medicinal plants against Ichthyophthirius multifiliis in goldfish (Carassius auratus)

Ichthyophthiriasis is a widespread disease in aquaculture and causes mass mortalities of fish. The development of new antiprotozoal agents for the treatment of Ichthyophthirius multifiliis infections is of increasing interest. The aim of the present study was to investigate the efficacy of 30 medicinal plants against I. multifiliis. The results showed that the methanol extracts of Magnolia officinalis and Sophora alopecuroides displayed the highest antiprotozoal activity against theronts, with 4-h LC(50) values estimated to be 2.45 and 3.43 mg L(-1), respectively. Concentrations of 2.5, 5.0, 10.0, and 20.0 mg L(-1) of M. officinalis extracts resulted in tomont mortality of 9.7, 43.7, 91.3, and 100% at 20 h, respectively. From 40 to 320 mg L(-1) of S. alopecuroides extracts, tomont mortality increased from 29.7 to 100%. Antiprotozoal efficacy against settled tomonts (2 and 10 h) was also applied; the results indicated that encysted I. multifiliis tomonts were less susceptible to these plant extract treatments. In vivo experiments demonstrated that high concentrations of M. officinalis and S. alopecuroides extracts could kill tomonts, and M. officinalis significantly reduced its reproduction (P < 0.05). These results suggested that the methanol extracts of M. officinalis and S. alopecuroides have the potential to be used as an eco-friendly approach for the control of I. multifiliis.

Effects of aqueous extract of Capsicum frutescens (Solanaceae) against the fish ectoparasite Ichthyophthirius multifiliis

Ichthyophthirius multifiliis is an important fish ectoparasite that often results in significant economic losses to freshwater aquaculture. The search of alternative substances to control infections of I. multifiliis became stringent after malachite green, an effective and widely used chemotherapeutant, is banned on fish farms because of its carcinogenicity and teratogenicity. In this study, the effects of the aqueous extract of Capsicum frutescens, which is readily available and affordable, were evaluated under in vitro and in vivo conditions. The results in the in vitro conditions showed that the aqueous extracts of C. frutescens with the ratios (V (SS)/V (T)-V (SS), the volume of stock solution; V (T), the volume of total solution) of 1:32 and 1:64 led to more than 70 % mortality of I. multifiliis theronts during 4 h of exposure and significantly reduced the survival of the tomonts and the total number of theronts released by the tomonts within 22 h (P < 0.05). A 96-h bioassay was carried out to determine the acute toxicity of the aqueous extract of C. frutescens to goldfish. No visible effect was observed in the treatments with the aqueous extracts of C. frutescens with the ratios (V (SS)/V (T)) of 1:32, 1:64 and 1:128, while in the other treatments, the erratic behaviour of fish was noted. In addition, in vitro tests demonstrated that the aqueous extract of C. frutescens had an adverse effect on I. multifiliis trophonts in situ. Fish treated with the aqueous extracts of C. frutescens in ratios V (SS)/V (T) of 1:32 and 1:64 carried significantly fewer parasites than the control and the other treatments (P < 0.05). These results suggest, therefore, that aqueous extracts of C. frutescens have potential for the control of ichthyophthiriasis in the aquaculture industry, though further phytochemical studies will need to be performed for isolation and identification of the active compounds.

Screening of 42 medicinal plants for in vivo anthelmintic activity against Dactylogyrus intermedius (Monogenea) in goldfish (Carassius auratus)

In the present study, methanol extracts of 42 traditional medicinal plants with potent anthelmintic activity against Dactylogyrus intermedius (Monogenea) in goldfish (Carassius auratus) were investigated. Cinnamomum cassia, Lindera aggregata, and Pseudolarix kaempferi exhibited 100% activity and were selected for further evaluation by applying five solvents (petroleum ether, chloroform, ethyl acetate, methanol, and water) for the extraction of the samples, followed by the in vivo bioassay. Among the extracts tested, water and methanol extracts of C. cassia showed the highest efficacies with EC(50) values of 13.2 and 12.3 mg L(-1), showing 100% efficacy against D. intermedius at 30.0 and 40.0 mg L(-1), followed by methanol extract of L. aggregata which demonstrated 100% efficacy at 60.0 mg L(-1) with EC(50) value of 17.1 mg L(-1) after 48 h of exposure. Methanol and ethyl acetate extract of P. kaempferi, which exhibited a 100% efficacy against D. intermedius at 60.0 and 50.0 mg L(-1), revealed similar activity with EC(50) values of 23.5 and 23.3 mg L(-1), respectively. Acute toxicity of these active extracts was investigated on goldfish for 48 h and the corresponding median lethal concentrations (LC(50)) of 56.9, 31.3, 88.7, 168.2, and 165.7 mg L(-1), respectively. These findings indicated that these extracts of the three plants can be developed as preferred natural antiparasitic agents for the treatment of D. intermedius.

Surface features of the monogenean gill parasites Pseudodactylogyrus anguillae and Pseudodactylogyrus bini from the European eel Anguilla anguilla in Egypt

In the present study, scanning electron microscopy is used to demonstrate the surface features of Pseudodactylogyrus anguillae Yin and Sproston (1948) Gussev, 1965 and Pseudodactylogyrus bini Kikuchi (1929) Gussev, 1965 from the European eel Anguilla anguilla. Specimens of the eel A. anguilla were collected from the River Nile, near Mansoura, Dakahlia Province, Egypt. Morphologically, P. anguillae could be distinguished from P. bini based on the total length, the shape and size of the haptor, and the constriction between the haptor and body proper. The general body tegument and the haptoral tegument of both species are microvillous. Possible functions of the microvilli associated with the tegument covering the anterior adhesive areas are discussed. The region of the body proper just anterior to the haptor of P. anguillae, appears to be highly folded and provided with many projections forming scale-like structures. Many surface ciliary sensilla presumed to be sensory structures are found on the tegument of the anterior adhesive area of P. anguillae. Secretory bodies and mucus-like substances are recorded on the tegument covering the anterior adhesive areas of P. anguillae and the haptor of P. bini. The possible role of these secretions in the attachment of the anterior adhesive areas and the posterior attachment haptor to the host tissues are also discussed.

In vivo anthelmintic activity of chelidonine from Chelidonium majus L. against Dactylogyrus intermedius in Carassius auratus

Dactylogyrus intermedius is one of the most common and serious cause of parasitic diseases of freshwater fish in aquaculture, and can cause morbidity and high mortality in most species of freshwater fish worldwide. To attempt controlling this parasite and explore novel potential antiparasitic agents, the present study was designed to ascertain the anthelmintic activity of Chelidonium majus L. whole plant and to isolate and characterize the active constituents against D. intermedius. The ethanol extract from C. majus whole plant showed significant anthelmintic activity against D. intermedius [EC(50) (median effective concentration) value = 71.5 mg L(-1)] and therefore subjected to further isolation and purification using various chromatographic techniques. A quaternary benzo[c]phenanthridine alkaloid exhibited significant activity against D. intermedius was obtained and identified as chelidonine. In vivo anthelmintic efficacy tests exhibited that chelidonine was 100% effective against D. intermedius at a concentration of 0.9 mg L(-1), with EC(50) value of 0.48 mg L(-1) after 48 h of exposure, which is more effective than the positive control, mebendazole (EC(50) value = 1.3 mg L(-1)). In addition, the 48-h median lethal concentration (LC(50)) for chelidonine against the host (Carassius auratus) was 4.54 mg L(-1). The resulting therapeutic index for chelidonine was 9.46. These results provided evidence that chelidonine might be potential sources of new antiparasitic drugs for the control of Dactylogyrus.

Activity of the chelerythrine, a quaternary benzo[c]phenanthridine alkaloid from Chelidonium majus L. on Dactylogyrus intermedius

Dactylogyrus intermedius is a significant monogenean parasite on the gills of cyprinid fishes and can cause severe economic losses in aquaculture and ornamental fish breeding. In the present study, bioactivity-guide fractionation was employed to identify active compound from Chelidonium majus L. against D. intermedius. In vivo anthelmintic activity of petroleum ether, ethyl acetate, chloroform, and n-butanol extracts of C. majus were tested. Among them, only the n-butanol extract exhibited promising anthelmintic efficacy, and therefore subjected to the further isolation and purification using various chromatographic techniques. A compound showing potent activity was obtained and identified by hydrogen, carbon-13 nuclear magnetic resonance spectrum and electron ionization mass spectrometry as chelerythrine. In vivo anthelmintic efficacy tests exhibited that chelerythrine was 100% effective against D. intermedius at a concentration of 1.60 mg L(-1), with LC(50) values of 0.68 mg L(-1) after 48 h of exposure. The 48-h LC(50) value (acute toxicity tests) of chelerythrine was found to be 3.59 mg L(-1) for grass carp. These results provided evidence that chelerythrine can be selected as a lead compound for the development of new drugs against D. intermedius.

Anthelmintic activity of steroidal saponins from Paris polyphylla

The present study was undertaken to investigate the anthelmintic activity of crude extracts and pure compounds from the rhizomes of Paris polyphylla. The methanol extract showed a promising anthelmintic activity against Dactylogyrus intermedius (EC(50) value=18.06 mg l(-¹). Based on these finding, the methanol extract was fractionated on silica gel column chromatography in a bioassay-guided fractionation affording two known steroidal saponins showing potent activity, dioscin and polyphyllin D. Both dioscin and polyphyllin D exhibited significant activity against D. intermedius with EC(50) values of 0.44 and 0.70 mg l(-¹), respectively, which were more effective than the positive control, mebendazole (EC(50) value=1.25 mg l(-¹)). The acute toxicities (LC(50)) of dioscin and polyphyllin D for goldfish were 1.37 and 1.08 mg l(-¹), respectively. These results indicated that P. polyphylla extract and the isolated compounds are potential natural agents for the control of Dactylogyrus infestation. This is the first report on in vivo anthelmintic investigation for P. polyphylla.

Anthelmintic activity of steroidal saponins from Dioscorea zingiberensis C. H. Wright against Dactylogyrus intermedius (Monogenea) in goldfish (Carassius auratus)

Dactylogyrus intermedius is one of the most pathogenic monogenean parasites on the gills of captive fish and can cause serious problem in aquaculture. To attempt controlling this parasite and explore novel potential antiparasitic agents, the present study was designed to investigate the anthelmintic activity of Dioscorea zingiberensis C. H. Wright against D. intermedius in goldfish under in vivo conditions. Bioactivity-guided fractionation and isolation of the compounds responsible for anthelmintic activity was carried out with the ethanolic extract yielding two bioactive compounds. Using MS, (1)H NMR, (13)C NMR spectroscopic analyses, the two compounds were identified as trillin and gracillin. The results of in vivo anthelmintic efficacy assay showed that the 48-h median effective concentrations (EC(50)) are 26.48 mg L(-1) for trillin and 0.18 mg L(-1) for gracillin. The 48-h acute toxicity tests (LD(50)) of trillin and gracillin were found to be 73.11 and 1.40 mg L(-1) for goldfish, respectively. The resulting therapeutic indices for the two active compounds are 2.76 and 7.78, respectively. These data confirmed that both trillin and gracillin are effective against D. intermedius, and the gracillin exhibits more interesting perspectives for the development of a candidate antiparasitic agent.