Anthelmintic activity of botanical extracts against sheep gastrointestinal nematodes, Haemonchus contortus

Phytochemical constituents, bioactivities, and applications of custard apple (Annona squamosa L.): A narrative review

Annona squamosa L. (Annonaceae) is a versatile tree with an edible fruit showing abundant medicinal and industrial applications. The nutritional values of this plant are due to carbohydrates, proteins, amino acids, and vitamins. Ethnopharmacological uses referred to treatment of dysentery, headlice, cancer sores, purgative, and tonic effects. The main reported biological activities for A. squamosa L. were cytotoxic, antidiabetic, antimicrobial, antiparasitic, antioxidant, antimalarial, molluscidal, anthelmintic and insecticidal activities, and its chemical classes encompassed alkaloids, diterpenes, acetogenins, and cyclopeptides. The nutritional content of A. squamosa L. and their main chemical components, biological effects, and the different applications were discussed in this review. This comprehensive review strived to compile all the relevant data in the period between 1990 and 2023 covering databases PubMed, ScienceDirect, Web of Science, Googlescholar and Reaxys concerning A. squamosa L. different parts with their reported phytochemical constituents and biological activities to integrate a better understanding of the medicinal values.

Synergistic Interaction Effect of Artemisia cina n-hexane Extract and Tagetes lucida Ethyl Acetate Extract on Haemonchus Contortus

PURPOSE

We analysed the possible synergistic activity among active extracts from Artemisia cina and Tagetes lucida combinations on Haemonchus contortus, a nematode parasitising sheep.

METHODS

The work was carried out in vitro on eggs and infective larvae (L3) of H. contortus. The results were analysed with SAS 9.1, applying the ANOVA and Tukey test, and the lethal concentration (LC) values LC50 and LC90 were determined with regression analysis, employing Proc Probit of SAS 9.1. Additionally, the lethal concentration (LC) was calculated with LC50 and LC90 to determine the synergistic effect.

RESULTS

The results demonstrated a high efficacy of the two plants studied on both nematode eggs and L3 larvae as well as of their combinations. The highest egg hatching inhibition was obtained with a 50/50 combination, and the best larvae mortality was obtained with 25% A. cina and 75% T. lucida at 10 mg/mL. Additionally, this combination showed a synergistic effect.

CONCLUSION

The two plant species studied here can be applied as natural anthelmintic alternatives due to their high bioactive effect and synergistic response.

Emerging alternatives to traditional anthelmintics: the in vitro antiparasitic activity of silver and selenium nanoparticles, and pomegranate (Punica granatum) peel extract against Haemonchus contortus

Haemonchus contortus (H. contortus) is one of the most prevalent gastrointestinal nematodes, causing health problems and economic losses in ruminants. Nanotechnology holds great promise as a field of science, with potential applications in veterinary medicine. This study investigated the in vitro anthelmintic activity of silver nanoparticles (AgNPs), selenium nanoparticles (SeNPs), and pomegranate peel extract (Punica granatum; PPE) on different stages of H. contortus: eggs, larvae, and adults. The in vitro anthelmintic efficacy was evaluated using the egg hatching inhibition assay (EHA), the third larval stage paralysis assay (LPA), and the adult worm motility inhibition assay (WMI). Six dilutions of PPE were utilized for EHA, LPA, and WMI, ranging from 0.25 to 6 mg/ml. AgNPs dilutions ranged from 0.00001 to 1.0 μg/ml for EHA and LPA and 1 to 25 μg/ml for WMI. SeNPs were utilized at dilutions of 1, 5, 10, and 15 μg/ml for EHA, LPA, and WMI. The results showed that the lowest concentration of AgNPs, SeNPs, and PPE significantly inhibited egg hatching. To further assess larvicidal activity, AgNPs at the highest concentration of 1 μg/ml induced a strong larvicidal effect, as did SeNPs at the lowest concentration. On the contrary, PPE displayed a significant larvicidal effect at 1 mg/ml compared to the control. The percentage mortality of adult H. contortus was measured as follows (mortality (%) = the number of dead adult H. contortus/total number of adult H. contortus per test × 100). The death of the adult H. contortus was determined by the absence of motility. Adult H. contortus mortality percentage was also significantly affected by all three agents when compared to the control. The AgNPs, SeNPs, and PPE have effective antiparasitic activity on gastrointestinal parasitic nematodes. These results provide evidence of the excellent antiparasitic properties of AgNPs, SeNPs, and PPE, demonstrating their effectiveness in controlling eggs, larvae, and adult H. contortus in vitro.

The diversity and quality of forages and their potency as herbal anthelmintic for swamp buffalo in Brebes District, Central Java

Background and Aim

Swamp buffaloes play an important role in the rural economy of Indonesia. They consume various forages during their grazing time, including those with anti-parasitic potential. However, the information about the type and quality of forages and their potential as a natural anthelmintic for swamp buffalo is very limited. This study aimed to identify the diversity, quality, and anthelmintic potency of forages consumed by swamp buffaloes reared in Bantarkawung Subdistrict, Brebes District, Central Java Province, Indonesia.

Materials and Methods

Samples of forages were obtained during three observation periods of the study, with a 12-week interval between each period. Forage diversity was evaluated by identifying its consumption by swamp buffaloes during their grazing activity in the field and feeding time in their shed. The quality of forages was analyzed using proximate analysis to measure their dry matter (DM), crude fiber (CF), crude protein (CP), crude fat (CFat), and ash contents. This is followed by the calculation of their total digestible nutrient based on the proximate analysis results. Botanical composition analysis was then conducted to measure the predominance of forages consumed by the livestock during their grazing activity. Literature reviews were carried out to explore forage's anthelmintic activity.

Results

The results showed that swamp buffaloes consume nine species of forage in the shed and 47 in the grazing area, including nine legumes, 18 grass, and 20 others. Swamp buffaloes consumed forages of lower quality, which contained high CF contents and varying levels of other nutrients below their daily nutritional needs. The grazing activity allowed swamp buffaloes to consume a higher variety of forages with better nutritional quality, thereby enabling them to meet their nutritional needs. Legumes and other forages served as the major protein sources, providing CP of 20.03% DM and 11.53% DM, and CF levels of 17.01% DM and 20.35% DM, respectively. The results also showed that the consumption of these forages increased during the rainy season. The predominant species of legumes consumed were Leucaena leucocephala and Acacia spp., while Alternanthera sessilis and Merremia umbellata were the predominant species of other forages. A total of 13 of the 47 species could potentially be used as natural anthelmintic due to their secondary metabolites, namely, tannin, flavonoid, saponin, terpenoid, diterpenoid, and mimosine. These compounds exert anthelmintic effects by inhibiting egg-hatching and larval development, as well as damaging the surface structure of both larvae and adult worms, ultimately leading to the death of the parasites.

Conclusion

Overall, swamp buffaloes consumed more variety of forages during grazing compared to when they were kept in sheds. While the low-variety and low-quality forages provisioned for swamp buffaloes in their shed resulted in a low nutrient intake below their daily requirement. Furthermore, daily grazing activities allowed swamp buffaloes to fulfill and supplement their need by consuming a variety of grasses, legumes, and other forages in their respective grazing areas. Some of these forages also have the potential to become natural anthelmintic because they contain secondary metabolites, such as tannins, flavonoids, saponins, terpenoids, diterpenoids, and mimosine.

Anthelmintic effect of four extracts obtained from Caesalpinia coriaria foliage against the eggs and larvae of Haemonchus contortus

To investigate the in vitro anthelmintic efficacy of dividivi (Caesalpinia coriaria), a traditional medicinal plant used in Central America and the northern part of South America, extracts from the foliage of this plant were subjected to the egg hatching test (EHT) and larval exsheathment inhibition test (LEIT), against Haemonchus contortus. Four different extracts were evaluated: acetone-water (AW), methanol-water (MW), acetone-water-dichloromethane (AWD) and methanol-water-dichloromethane (MWD). The concentrations used for the EHT and LEIT tests ranged from 500 to 4000 µg mL-1 and six repetitions per concentration. The effective concentrations (EC50) were calculated using Probit analysis. The EC50 for EHT were 2947.0, 3347.0, 3959.6 and 4538.7 µg mL-1 for MWD, MW, AW and AWD, respectively. The EC50 for LEIT were 2883.4, 5927.4, 9876.3 and 9955.4 µg mL-1 for AWD, AW, MWD and MW, respectively. The methanol extracts were the most effective in inhibiting the hatching of eggs, while the acetone extracts showed efficacy in inhibiting larval exsheathment. This study explains the importance that C. coriaria has as a medicinal plant in Central and South American countries.

A Systematic Review on Comparative Analysis, Toxicology, and Pharmacology of Medicinal Plants Against Haemonchus contortus

Background:Haemonchus contortus is an important pathogenic nematode parasite and major economic constraint of small ruminants in tropics and subtropics regions. This review is an attempt to systematically address the; (a) efficacy of different plants against H. contortus by in vitro and in vivo proof; (b) toxicology, mechanism of action, and active phyto-compounds involve in anti-haemonchiasis activity; (c) and comparative analysis of plant species evaluated both in vitro and in vivo.

Methods: Online databases (Google Scholar, PubMed, Scopus, and ScienceDirect) were searched and published research articles (1980–2020) were gathered and reviewed.

Results: A total of 187 plant species were reported belonging to 59 families and 145 genera with Asteraceae and Fabaceae being frequently used. Out of the total plant species, 171 species were found to be evaluated in vitro and only 40 species in vivo. Twenty-four species were commonly evaluated for in vitro and in vivo anti-haemonchiasis activity. Among the reported assays, egg hatching test (EHT) and fecal egg count reduction (FECR) were the most widely used assays in vitro and in vivo, respectively. Moreover, sheep were the frequently used experimental model in vivo. After comparative analysis, Lachesiodendron viridiflorum, Corymbia citriodora, Calotropis procera, and Artemisia herba-alba were found highly effective both in vitro and in vivo. L. viridiflorum inhibited enzymatic activities and metabolic processes of the parasite and was found to be safe without toxic effects. C. citriodora was moderately toxic in vivo, however, the plant extract produced promising nematicidal effects by causing muscular disorganization and changes in the mitochondrial profile. Additionally, C. procera and A. herba-alba despite of their high anti-haemonchiasis activity were found to be highly toxic at the tested concentrations. C. procera caused perforation and tegumental disorganization along with adult worm paralysis. Nineteen compounds were reported, among which anethole and carvone completely inhibited egg hatching in vitro and significantly reduced fecal egg count, decreased male length, and reproductive capacity of female in vivo.

Conclusion: This review summarized different medicinal plants owing to nematicidal activities against H. contortus eggs, larvae, and adult worms. Plants like L. viridiflorum, C. citriodora, C. procera, and A. herba-alba, while compounds anethole and carvone having promising nematicidal activities and could be an alternative source for developing novel drugs after further investigation.

Small Ruminant Production Based on Rangelands to Optimize Animal Nutrition and Health: Building an Interdisciplinary Approach to Evaluate Nutraceutical Plants

The plant kingdom can influence the productivity and health of herbivores at different levels. However, demonstrating this process in a scientific manner entails substantial endeavors from different disciplines. In the present review, we will describe the features of a native vegetation system traditionally used by small ruminants and use its particularities to build an interdisciplinary approach to evaluate the nutraceutical properties of plants. Initially, we will establish the context of the low deciduous forest (LDF), considering some botanical and nutritional aspects, as well as the presence of plant secondary compounds (PSC) and gastrointestinal nematodes (GIN). Furthermore, we will focus on coevolutionary aspects that undoubtedly shaped the plants-nutrients-PSC-GIN-herbivore relationship. In addition, the concept of nutraceutical will be discussed to provide clarity and aspects to be considered for their evaluation. Then, ethological, agronomical, nutritional, PSC, parasitological and animal species issues are deepened placing emphasis on methodological approaches. Special focus is given to condensed tannins, as they are the fourth largest group of PSCs and the most studied in livestock sciences. Validation of the nutraceutical properties of plants from native vegetation systems should be seen as a process derived from many scientific disciplines that feed into each other in a cyclic manner.

Chemical characterization and in vitro biological activity of Cymbopogon citratus extracts against Haemonchus spp. and Trichostrongylus spp. nematodes from sheep

Medicinal plants have been the focus of several studies due to their nematicide properties which can be used to control nematodes in sheep. No study has examined the morphological effects of Cymbopogon citratus on nematodes. Thus, this study evaluated the chemical composition, nematicidal activity and effects of C. citratus extracts on the morphology of eggs and infective larvae (L3) of sheep. Aqueous and methanolic extracts and fractions of C. citratus were obtained and analysed in vitro. The C. citratus extracts were effective against Haemonchus spp. and Trichostrongylus spp. larvae and eggs. Ten fractions were obtained from C. citratus, six of which had high ovicidal activity at 1000 μg mL-1, and two fractions had high activity at all tested concentrations. The phytochemical analysis identified the presence of compounds such as terpenoids, various ketones, esters, and fatty acids. The ultrastructural analysis showed deformations of the cuticle and wilting along the body of the nematodes at all concentrations. The muscular layer, intestinal cells and the mitochondria profile showed damage compared to the typical pattern. Ultra-thin sections of eggs treated with methanolic fractions of C. citratus presented modifications. This study showed the biological activity and effects of C. citratus on the gastrointestinal nematodes in sheep.

Effects of different extracts of three Annona species on egg-hatching processes of Haemonchus contortus

This study assessed the in vitro anthelmintic (AH) activity of methanol and acetone:water leaf extracts from Annona squamosa, A. muricata and A. reticulata against Haemonchus contortus eggs. The egg hatch test was used to determine the effective concentrations required to inhibit 50% of eggs hatching (EC50). The role of polyphenols on AH activity was measured through bioassays with and without polyvinylpolypyrrolidone (PVPP). Methanolic extracts mainly caused the death of eggs at the morula stage (ovicidal activity). Meanwhile, acetone:water extracts caused egg-hatching failure of developed larvae (larvae failing eclosion (LFE) activity). The lowest EC50 values against H. contortus eggs were observed for the methanolic extracts from A. reticulata and A. muricata (274.2 and 382.9 µg/ml, respectively). From the six extracts evaluated, the methanolic extracts of A. muricata, A. reticulata and A. squamosa showed the highest ovicidal activity, resulting in 98.9%, 92.8% and 95.1% egg mortality, respectively. When the methanolic extract of A. squamosa was incubated with PVPP, its AH activity increased. Similarly, when acetone:water extracts of A. muriata and A. reticulata were incubated with PVPP, their LFE activity increased. Alkaloids were only evident in methanolic extracts, irrespective of PVPP incubation. The presence of acetogenins was not observed. In conclusion, methanolic extracts obtained from leaves of A. muricata, A. reticulata and A. squamosa showed ovicidal activity affecting the morula of H. contortus eggs, with minor LFE activity. Meanwhile, acetone:water extracts showed mostly LFE activity, with a lower proportion of ovicidal activity.

Characterization of the Metabolic Fate of Datura metel Seed Extract and Its Main Constituents in Rats

Datura metel L. has been frequently used in Chinese traditional medicine. However, little is known on the chemical composition and in vivo metabolism of its seeds. In this study, using the strategy "chemical analysis, metabolism of single representative compounds, and metabolism of extract at clinical dosage" that we propose here, 42 constituents were characterized from D. metel seeds water extract. Furthermore, the metabolic pathways of 13 representative bioactive compounds of D. metel seeds were studied in rats after the oral administration of D. metel seeds water extract at a clinical dosage (0.15 g/kg). These included three withanolides, two withanolide glucosides, four amides, one indole, one triterpenoid, one steroid, and one sesquiterpenoid, and with regard to phase II metabolism, hydroxylation, (de)methylation, and dehydrogenation reactions were dominant. Furthermore, the metabolism of D. metel seeds water extract provided to rats at a clinical dosage was investigated by liquid chromatography-tandem mass spectrometry based on the above metabolic pathways. Sixty-one compounds were detected in plasma, 83 in urine, and 76 in fecal samples. Among them, withanolides exhibited higher plasma exposure than the other types. To our knowledge, this is the first systematic study on the chemical profiling and metabolite identification of D. metel seeds, including all compounds instead of single constituents.

The Genus Solanum: An Ethnopharmacological, Phytochemical and Biological Properties Review

Over the past 30 years, the genus Solanum has received considerable attention in chemical and biological studies. Solanum is the largest genus in the family Solanaceae, comprising of about 2000 species distributed in the subtropical and tropical regions of Africa, Australia, and parts of Asia, e.g., China, India and Japan. Many of them are economically significant species. Previous phytochemical investigations on Solanum species led to the identification of steroidal saponins, steroidal alkaloids, terpenes, flavonoids, lignans, sterols, phenolic comopunds, coumarins, amongst other compounds. Many species belonging to this genus present huge range of pharmacological activities such as cytotoxicity to different tumors as breast cancer (4T1 and EMT), colorectal cancer (HCT116, HT29, and SW480), and prostate cancer (DU145) cell lines. The biological activities have been attributed to a number of steroidal saponins, steroidal alkaloids and phenols. This review features 65 phytochemically studied species of Solanum between 1990 and 2018, fetched from SciFinder, Pubmed, ScienceDirect, Wikipedia and Baidu, using "Solanum" and the species' names as search terms ("all fields").

Anthelmintic efficacy of cranberry vine extracts on ovine Haemonchus contortus

The discovery that plant secondary compounds, including proanthocyanidins (PAC), suppress gastrointestinal nematode (GIN) infection has provided promise for alternative methods of GIN control in small ruminants. This investigation is the first to examine the anthelmintic potential of cranberry vine (CV) against the GIN Haemonchus contortus. The purpose of this study was to explore the anti-parasitic activity of CV in the form of a specific organic proanthocyanidin extract (CV-PAC) and an aqueous extract (CV-AqE) containing PAC and other compounds. In vitro egg hatching, first (L1) and third (L3) stage larval and adult worm motility and L3 exsheathment were evaluated after a 24-h incubation with CV products. In addition, CV treated worms were observed via scanning electron microscopy, and a preliminary investigation of the efficacy of CV powder against an experimental infection of H. contortus was conducted. The in vivo effect on an experimental infection was determined by administering 21.1 g CV powder to lambs (n = 9 per group) for three consecutive days, and collecting fecal egg count data for four weeks post-treatment. The effect of CV-PAC on egg hatching, L3 motility and exsheathment was limited. However, a substantial effect was observed on motility of post-hatch L1 (EC₅₀ 0.3 mg PAC/mL) and adults (EC₅₀ 0.2 mg PAC/mL). The CV-AqE showed more effect on egg hatching (EC₅₀ 5.3 mg/mL containing 0.6 mg PAC/mL) as well as impacting motility of L1 (EC₅₀ 1.5 mg/mL with 0.2 mg PAC/mL) and adults (EC₅₀ 3.4 mg/mL with 0.4 mg PAC/mL), but like CV-PAC, did not substantially effect L3 motility or exsheathment. Scanning electron microscopy revealed an accumulation of aggregate on the cuticle around the buccal area of adult worms incubated in CV-AqE and CV-PAC. In the preliminary in vivo study, there was a significant effect of treatment over time (p = .04), although differences in individual weeks were not significant. In summary, both extracts inhibited motility of L1 and adult worms. The higher efficacy of CV-AqE than CV-PAC at levels that contained the same concentrations of PAC tested alone, suggest that other secondary compounds in the CV-AqE contributed to the observed effects on the parasites. This first study of the in vitro and in vivo effects of CV suggest that this readily available plant product may have utility in integrated control of H. contortus and support the need for additional testing to provide further information.

Terminalia catappa: Chemical composition, in vitro and in vivo effects on Haemonchus contortus

Haemonchus contortus is the most important nematode in small ruminant systems, and has developed tolerance to all commercial anthelmintics in several countries. In vitro (egg hatch assay) and in vivo tests were performed with a multidrug strain of Haemonchus contortus using Terminalia catappa leaf, fruit pulp, and seed extracts (in vitro), or pulp and seed powder in lambs experimentally infected with H. contortus. Crude extracts from leaves, fruit pulp and seeds obtained with 70% acetone were lyophilized until used. In vitro, the extracts had LC₅₀=2.48μg/mL (seeds), LC₅₀=4.62μg/mL (pulp), and LC₅₀=20μg/mL (leaves). In vitro, seed and pulp extracts had LC₅₀ similar to Thiabendazole (LC₅₀=1.31μg/mL). Condensed tannins were more concentrated in pulp extract (183.92g of leucocyanidin/kg dry matter) than in either leaf (4.6g) or seed (35.13g) extracts. Phytochemical tests established that all extracts contained alkaloids, flavonoids, saponins, phenols, and terpenoids. Based on these results, in vivo tests were performed to evaluate the anthelmintic activity of T. catappa whole fruit (pulp+seed) powder. Male Santa Ines lambs were artificially infected with multidrug-resistant H. contortus and divided, according to similar fecal egg count (FEC) and weight, into two groups: Control (infected/untreated) and treated (infected/treated with whole fruit powder). Whole fruit powder was mixed with concentrate and provided at 2g/kg of body weight (BW) for five days. After treatment, parasitological analysis (FEC and egg hatch assay), renal profile (urea and creatinine), liver profile (aspartate aminotransferase) and BW were determined. In vitro (based on LC₅₀), seed/pulp extracts had ovicidal effect similar to Thiabendazole but whole fruit powder had no anthelmintic effect on adult nematodes in the abomasum. We discuss the plausible causes of the lack of in vivo activity.

In vitro control of parasitic nematodes of small ruminants using some plant species containing flavonoids

This study determined in vitro anthelmintic efficacy of three plant species: Trema orientalis, Urtica dioica and Zanthozylum capense on nematode larvae of small ruminants. Dried leaf samples (40 g) were extracted in 70% ethanol, in portions of 10 g and concentrated to 100 ml. Half and one quarter of the original crude extract were both made to 100 ml. Rectal faecal material from 10 Merino sheep and 25 Nguni goats was pooled within species and thoroughly hand-mixed. Dung samples, each of 5 g were cultured for 12 days at 27 °C. On day 13, 4 plates were watered and 4 others treated with ethanol to correct for solvent effect on mortality. The design was 2 (animal species) × 3 (plant species) × 3 (extract concentrations). In each of three runs, three plates were treated with each crude extract in three incremental concentrations. Surviving L3 larvae were isolated, counted and mortalities became indices of anthelmintic efficacy. Data from nematode larval mortality were analysed to determine the effect of animal species, plant species, concentration and their interactions. Efficacy was affected by concentration (P = 0.0001), animal species (P = 0.0046), plant species (P = 0.0572), the interactions of animal species and concentration (P = 0.0010), plant species and concentration (P = 0.0123) and concentration × animal × plant species (P = 0.0435).

Evaluation of anthelmintic activity of biologically synthesized silver nanoparticles against the gastrointestinal nematode, Haemonchus contortus

The present study focuses on the in vitro anthelmintic activity of silver nanoparticles (AgNPs) synthesized using the aqueous extract of Azadirachta indica against Haemonchus contortus. The synthesized AgNPs were characterized by ultraviolet-visible (UV-Vis) spectrophotometry, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) studies. The UV-Vis spectrum exhibited a sharp peak at 420 nm, which was validated by electron microscopy, indicating the preparation of spherical nanoparticles measuring 15-25 nm in size. The in vitro study was based on an egg hatch assay (EHA) and adult motility inhibition assays. Six concentrations of AgNPs were used for EHA, ranging from 0.00001 to 1.0 μg/ml, and a range of 1-25 μg/ml was used for adult worms. The highest concentration induced 85 ± 2.89% egg hatch inhibition. The IC50 value for EHA was 0.001 μg/ml, whereas in vitro adult H. contortus motility inhibition was produced at 7.89 μg/ml (LC50). The effectiveness of A. indica leaf extract (aqueous) was also evaluated, which showed an IC50 value for EHA of 115.67 μg/ml, while the LC50 against adult H. contortus was 588.54 μg/ml. The overall findings of the present study show that the experimental plant extract contains reducing properties for the synthesis of AgNPs which, in turn, showed potent anthelmintic properties. This is the first report where AgNPs have been tested for their anthelmintic properties in an in vitro model.

Antidiabetic Medicinal Plants Used by the Basotho Tribe of Eastern Free State: A Review

Diabetes mellitus (DM) belongs to the group of five leading important diseases causing death globally and remains a major health problem in Africa. A number of factors such as poverty, poor eating habit, and hormonal imbalance are responsible for the occurrence of the disease. It poses a major health challenge in Africa continent today and the prevalence continues to increase at an alarming rate. Various treatment options particularly the usage of herbs have been effective against diabetes because they have no adverse effects. Interestingly, South Africa, especially the Basotho tribe, is blessed with numerous medicinal plants whose usage in the treatment of DM has been effective since the conventional drugs are expensive and often unaffordable. The present study attempted to update the various scientific evidence on the twenty-three (23) plants originating from different parts of the world but widely used by the Sotho people in the management of DM. Asteraceae topped the list of sixteen (16) plant families and remained the most investigated according to this review. Although limited information was obtained on the antidiabetic activities of these plants, it is however anticipated that government parastatals and scientific communities will pay more attention to these plants in future research.

In vitro anthelmintic activity of active compounds of the fringed rue Ruta chalepensis against dairy ewe gastrointestinal nematodes

Infections by gastrointestinal nematodes negatively affect small ruminant health and at the same time cause substantial economic losses worldwide. Because resistance to conventional anthelmintic compounds is growing, target studies evaluating the effectiveness of alternative ingredients of botanical origin on gastrointestinal nematodes are needed. In this study, we evaluated the in vitro anthelmintic activity of Ruta chalepensis L. extracts on the third-stage larvae of sheep gastrointestinal nematodes. A methanol extract showed the highest anthelmintic activity, with an EC50 = 0.10 ± 0.06 mg/ml after 96 h, while the essential oil had an EC50 = 1.45 ± 1.22 mg/ml after 48 h. Moreover, three secondary metabolites of the essential oil, i.e. 2-decanone, 2-nonanone and 2-undecanone, showed EC50 values of 0.07 ± 0.06, 0.25 ± 0.29 and 0.88 ± 0.73 mg/ml at 24 h, respectively. The present study indicated that the R. chalepensis methanol extract, the essential oil and its metabolites 2-decanone, 2-nonanone and 2-undecanone showed promising anthelmintic activity on gastrointestinal nematodes.

Anthelmintic activity of acetone-water extracts against Haemonchus contortus eggs: interactions between tannins and other plant secondary compounds

This study aimed at (i) describing the effects of acetone-water extracts obtained from a range of different plant materials, on the hatching process of Haemonchus contortus eggs under in vitro conditions and (ii) identifying the role of tannins and other plant secondary compounds (PSC), on these AH effects by using polyvinylpolypyrrolidone (PVPP), an inhibitor of tannins and other polyphenols. An egg hatch assay (EHA) was used to determine the AH effect. Acetone-water (70:30) extracts from different foliages (Lysiloma latisiliquum, Laguncularia racemosa, Rizophora mangle, Avicennia germinans) and plant by-products (Theobroma cacao seed husk and pulp, and percolated Coffea arabica) were obtained. Fresh H. contortus eggs were incubated in PBS with increasing concentrations of each extract (0, 600, 1200, 2400 and 3600 μg/ml PBS). A general linear model was used to determine the dose effect of each extract. A mild ovicidal activity was only recorded for T. cacao extracts (seed husk and pulp). The main anthelmintic (AH) effect for all the extracts, except for C. arabica, was to block the eclosion of larvated eggs. The use of PVPP at 3600 μg/ml PBS showed that tannins of the L. racemosa extract were responsible for blocking eclosion of larvated eggs. Extracts of L. latisiliquum, A. germinans, T. cacao seed husk and pulp also blocked eclosion of larvated eggs but the addition of PVPP indicated that tannins were not responsible for that activity. In contrast, it suggested unfavorable interactions between polyphenols and other PSC contained in those extracts, limiting the AH effect on the egg hatching process. The present results suggest that the interactions between tannins and other PSC are complex and may reduce the AH effects against H. contortus eggs.

Haemonchus contortus: Applications in Drug Discovery

Haemonchus contortus is an important pathogen of small ruminants and is therefore a crucially important target for anthelmintic chemotherapy. Its large size and fecundity have been exploited for the development of in vitro screens for anthelmintic discovery that employ larval and adult stages in several formats. The ability of the parasite to develop to the young adult stage in Mongolian jirds (Meriones unguiculatus) provides a useful small animal model that can be used to screen compounds prior to their evaluation in infected sheep. This chapter summarizes the use of H. contortus for anthelmintic discovery, offers a perspective on current strategies in this area and suggests research challenges that could lead to improvements in the anthelmintic discovery process.

Relative resistance of Menz and Washera sheep breeds to artificial infection with Haemonchus contortus in the highlands of Ethiopia

The aim of this study was to evaluate the relative resistance of Menz and Washera sheep breeds to artificial infection with Haemonchus contortus. The challenge trial was conducted at the Debre Berhan Agricultural Research Center in Ethiopia. A total of 39 (Menz = 21, Washera = 18) lambs of about 6 months old were used for the trial. All lambs were initially treated against internal parasite using albendazole and Fasinex to free them from internal parasites and kept indoors. H. contortus third-stage larvae (L3) were prepared according to standard procedure from adult female parasite collected from abattoirs and recovered using the Baerman technique. Approximately 5000 infective larvae were inoculated to the experimental lambs at about 5 weeks after deworming. Fecal egg count (FEC), packed cell volume (PCV), FAffa MAlan CHArt (FAMACHA) score, lamb body weight, and survival of lambs were recorded at 28, 35, and 42 days after challenge. Breed effect was not significant (P > 0.05), whereas time of measurement and the interaction of breed and time had significant (P < 0.05) effects on FEC and PCV. At 28 days after challenge, Menz sheep had lower FEC than Washera sheep, whereas at days 35 and 42, the Washera sheep had lower FEC than Menz lambs. The PCV decreased significantly throughout the post-challenge period. Despite their parasite burden, Menz sheep were able to maintain live weight during the 42 days of challenge. Chi-square tests for breed differences in lamb survival were not significant at any time (28, 35, and 42 days after challenge). Lower FEC at 28 days and delayed rise in FEC after infection in Menz lamb would allow in delaying anthelmintic treatment. In addition to maintain body weights during the infection period, sheep of both breeds exhibited substantial variability in PCV and FEC, suggesting opportunity to consider parasite resistance in selection program.

In vitro ovicidal assessment of methanol, ethyl acetate and chloroform extracts of Annona squamosa and Chenopodium album against caprine gastrointestinal nematodiosis

The objective of this study was in vitro evaluation of the ovicidal efficacy of methanol, ethyl acetate and chloroform extracts of Annona squamosa (seeds) and Chenopodium album (whole plant) in comparison to albendazole against the GI nematodes of goats using egg hatch test. Eggs of GI nematodes were incubated at 27 °C in different extracts at concentration of 100-6.25 mg/ml for 2 days. Distilled water and albendazole were used as negative and positive controls, respectively. Percentage efficacy and ED50 and ED90 values were separately evaluated with upper and lower confidence limit by log probit analysis using SAS 9.2. The ED50 and ED90 values of methanolic, ethyl acetate and chloroform extracts of A. squamosa was calculated as 1.52 and 4.56; 2.48 and 10.73; 3.02 and 12.44 mg/ml, respectively against GI nematodes if goats. Similarly, the ED50 and ED90 values of methanolic, ethyl acetate and chloroform extracts of C. album was calculated as 3.86 and 7.14; 2.73 and 8.31; 4.41 and 20.11 mg/ml, respectively This study shows that C. album and A. squamosa possess in vitro anthelmintic activities. The study also suggests further large scale pharmacological and toxicological studies for their safer use in veterinary medicine.

Anti-tumor activity of Annona squamosa seeds extract containing annonaceous acetogenin compounds

ETHNOPHARMACOLOGICAL RELEVANCE

Seeds of Annona squamosa L. have been used in the south of China as a folk remedy to treat "malignant sores" (cancer).

AIM OF THE STUDY

To investigate the chemical constituents and the anti-tumor activity of the standardized A. squamosa seeds extract in vitro and in vivo.

MATERIALS AND METHODS

Annonaceous acetogenin profiles of the standardized extract were determined by using Fourier transform infrared (FT-IR) and high performance liquid chromatography (HPLC) techniques. The anti-tumor activity of the extract was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) cytotoxicity in vitro and H(22) hepatoma cells transplantation tumor model in vivo.

RESULTS

The FT-IR spectroscopy showed the presence of annonaceous acetogenin compounds in the extract. Two major annonaceous acetogenins: 12, 15-cis-squamostatin-A and bullatacin were identified and quantified by HPLC. The seed extract showed significant anti-tumor activity against four human tumor cell lines, especially for MCF-7 (IC(50). 0.25 μg/ml) and Hep G2 (IC(50). 0.36 μg/ml) cells in vitro. The extract inhibited the growth of H(22) tumor cells in mice with a maximum inhibitory rate of 69.55% by oral administration.

CONCLUSION

A. squamosa seed extract showed significant anti-tumor activities against human hepatoma cells in vitro and in vivo, indicating a potential for developing the extract as a novel anti-liver cancer drug.

In vivo anthelmintic activity of Clerodendrum colebrookianum Walp., a traditionally used taenicidal plant in Northeast India

Although there are several effective drugs available for the treatment of intestinal helminths, the fact remains that they continue to remain out of reach to a vast majority of people in the world, especially in developing countries. On the other hand, there are a great many herbal remedies that are effective against common intestinal worms and are easily available to common people in developing countries. Clerodendrum colebrookianum Walp. (Lamiaceae) is a perennial shrub which is native to South and Southeast Asia. Traditionally, the leaves of this plant are used by the indigenous people of Northeast India as a remedy for the treatment of intestinal tapeworm infections. The aim of this study was to evaluate and authenticate the anthelmintic efficacy of C. colebrookianum leaf extract in experimentally induced Hymenolepis diminuta (a zoonotic tapeworm) infections in Wistar rats. The efficacy of the plant extract was assessed by monitoring the eggs per gram of faeces (EPG) counts and worm recovery rates of experimental animals, following treatment with the leaf extract of this plant at three different doses, i.e. 200, 400 and 800 mg/kg body weight, each given singly for 5 days. The results obtained revealed that the leaf extract of C. colebrookianum possesses a dose-dependent efficacy against the larval, immature and adult stages of H. diminuta. However, the efficacy of the extract was found to be considerably high only against the adult stages of the parasite. For this stage, a single 800-mg/kg dose of extract, given for 5 days, resulted into 68.42% reduction in the EPG counts and 62.50% reduction in the worm counts in the extract-treated group of animals, as compared to the control. The reference drug, praziquantel (5 mg/kg, single dose), however, showed slightly better efficacy and caused 95.16 and 87.00% reductions in the EPG and worm counts of treated animals, respectively. Unlike the adult stages, the efficacy of the plant extract was recorded to be comparatively low against the larval and immature stages of the parasite, as the treatment of animals with the highest dose of extract (800 mg/kg) could cause only 37.50 and 54.00% reductions in worm counts, respectively. The experimental evidence obtained in this study suggests that leaves of C. colebrookianum possess significant anthelminthic properties and supports their use against intestinal tapeworm infections in traditional medicine.

Anthelmintic activity of medicinal plants used in Côte d'Ivoire for treating parasitic diseases

Natural products play an important role in the discovery and development of new pharmaceuticals. In the present study, we assessed the anthelmintic properties of medicinal plants used in Cote d'Ivoire. Ethanolic extracts from 50 medicinal plants were tested in vitro against trematodes (Echinostoma caproni, Schistosoma mansoni) and nematodes (Ancylostoma ceylanicum, Heligmosomoides bakeri, Trichuris muris). Active extracts were evaluated for their cytotoxicity and followed up in vivo in mice harbouring adult S. mansoni, E. caproni and T. muris at single oral doses of 400 or 800 mg/kg. All extracts tested were active against at least one helminths species. Ten of the 65 extracts tested (15.4%) in vitro revealed activity against all helminths tested. Of 65 extracts tested in vitro at a concentration of 2 mg/ml, all caused death of schistosomula and 34.4% and 39.1% were lethal against adult S. mansoni and E. caproni 72 h post-incubation, respectively. The highest activity against A. ceylanicum in vitro was observed with Sclerocarya birrea at 2 mg/ml, which resulted in death of adult worms and inhibition of activity of third-stage larvae (L3). Of the extracts, 41.5% completely inhibited movement of H. bakeri L3 at minimal lethal concentration (MLC) values of 20-200 μg/ml 48 h post-incubation, and 15.4% paralysed adult H. bakeri at 200 μg/ml 72 h after incubation. Of the extracts, 19% resulted in death of adult T. muris at MLC values of 10-100 μg/ml. In vivo, none of the extracts tested revealed activity against E. caproni. Olax subscorpioidea achieved total and female worm burden reductions of 60% and 84%, respectively in S. mansoni-infected mice. Combretum mucronatum was the most active extracts in vivo against T. muris with a worm burden reduction of 85.3%. In conclusion, several of the medicinal plants used in Côte d'Ivoire are active against different helminths, hence might play a role in the treatment of helminthiases. Further studies are necessary to isolate the active components from these extracts.

Small ruminant resistance against gastrointestinal nematodes: a case of Haemonchus contortus

Gastrointestinal nematode (GIN) infections are a common constraint to small ruminant industry throughout the world, and among those, haemonchosis has its own significance. Control of GIN primarily relies on the use of anthelmintics, but this approach has become less reliable due to the development of resistance in GINs against commonly used anthelmintics and an increased consumer demand for environmentally friendly animal products. These issues have stimulated investigations to find alternative sustainable control strategies, which are less reliant on anthelmintic input. One of such strategies is breeding of small ruminants for their resistance to the GINs. The susceptibility and resistance of animals to GIN infections varies within and between breeds. Various parasitological, biochemical and immunological parameters are employed to evaluate natural resistance status of animals both in natural pasture and artificial infections. The immune mechanisms responsible for resistance are not completely understood, but it has a significant effect in inherited resistance. Relatively resistant or tolerant animals show better local and generalised immune response as compared to susceptible. Immune response against GINs is influenced by many physiological factors. Determination of specific genes linked with host resistance will provide a valuable approach to find out the molecular mechanism of host resistance to GINs. Resistance has been reported to reduce pasture contamination, which in turn reduces re-infection and thus the requirement of the frequent anthelmintic treatments. The efficiency of control can be increased through objective and accurate identification of genetically tolerant individuals by natural and artificial infections with GINs. Complete resistance is the ultimate solution, but this has generally been ignored as a commercial reality. This paper reviews the published reports on natural resistance in small ruminants and discusses the prospects of developing small ruminants, which could be resistant to GINs.