Quality, supply chain, and use of Trypanocidal drugs among camel keepers in north-eastern Kenya: A cross-sectional study.

The non-cyclic trypanosomiasis (surra), caused by Trypanosoma evansi, and mechanically transmitted by biting flies, hinders camel productivity in Kenya. Trypanocides are the most commonly used drugs to control surra. However, emergence of drug resistance by the parasites is a major limitation to control efforts. There is limited information on the quality of trypanocides, the supply chain and drug-use practices among camel keepers potentially contributing to development of drug resistance in Kenya. We sought to fill this gap by conducting a cross-sectional study among camel keepers in Isiolo and Marsabit counties, Kenya. We mapped the trypanocide drugs supply chain through quantitative and qualitative surveys. We administered a semi-structured questionnaire to camel keepers to generate data on trypanocides-use practices, including the types, sources, person who administers treatment, reconstitution, dosage, route and frequency of administration, among others. Additionally, we tested the quality of trypanocidal drugs retailed in the region. We mapped a total of 55 and 49 agro-veterinary outlets and general (ordinary) shops retailing veterinary drugs in the two counties, respectively. These comprised of 29 and 26 agro-veterinary outlets, as well as 24 and 25 general shops in Isiolo and Marsabit counties, respectively. Overall, the respondents experienced 283 surra cases in the three-month recall period, which were treated with trypanocides. The majority of these cases were diagnosed by camel owners (71.7%) and herders (24.1%). A significant proportion of the cases were treated by camel owners (54.8%), herders (35.3%), the owner's son (3.2%) and veterinary personnel (1.1%) (χ2 = 24.99, p = 0.000). Most of the households sourced the drugs from agro-veterinary outlets (59.0%), followed by general shops (19.8%), veterinary personnel (2.1%), and open-air markets (0.4%) (χ2 = 319.24, p = 0.000). Quinapyramine was the most (56.9%) predominantly used trypanocide in treatment of surra, followed by homidium (19.8%), isometamidium (15.9%), diminazene aceturate (6.7%), and ethidium (0.7%) (χ2 = 340.75, p < 0.000). Only a meager proportion of respondents (15.2%) used the drugs correctly as instructed by the manufacturers. We recorded an association between correct drug usage, with the person who administers the treatment (χ2 = 17.7, p = 0.003), and the type of trypanocide used (χ2 = 19.4, p < 0.001). All the drug samples tested had correct concentrations of active ingredient (100.0%), and therefore of good quality. We have demonstrated that whereas the trypanocides retailed in the region by authorized vendors are of good quality, there is widespread incorrect handling and use of the drugs by unqualified individuals, which may contribute to treatment failure and emergence of trypanocide resistance.

Long-term antitrypanosomal effect of quinapyramine sulphate-loaded oil-based nanosuspension in T. evansi-infected mouse model.

The goal of the present work consisted of the formulation development and evaluation of quinapyramine sulphate (QS)-loaded long-acting oil-based nanosuspension for improved antitrypanosomal effect. QS was transformed into a hydrophobic ionic complex using anionic sodium cholate (Na.C). The complex was characterized by FTIR, DSC, and XRD. Oil-based nanosuspension was prepared by dispersing the QS-Na.C complex in thixotropically thickened olive oil. The nanoformulation was found to be cytocompatible (82.5 ± 5.87% cell viability at the minimum effective concentration [MEC]) in THP-1 cell lines and selectively trypanotoxic (p < 0.0001). The pharmacokinetic studies of QS-Na.C complex-loaded oily nanosuspension showed 13.54-fold, 7.09-fold, 1.78-fold, and 17.35-fold increases in t1/2, AUC0-∞, Vz/F, and MRT0-ꝏ, respectively, as compared to free QS. Moreover, a 7.08-fold reduction in plasma clearance was observed after the treatment with the optimized formulation in Wistar rats. Furthermore, treatment with QS-Na.C complex-loaded oily nanosuspension (7.5 mg/kg) in T. evansi-infected mice model showed the absence of parasitaemia for more than 75 days after the treatment during in vivo efficacy studies. The efficacy of the treatment was assessed by observation of blood smear and PCR assay for DNA amplification. To conclude, our findings suggest that the efficient delivery of QS from the developed QS-Na.C complex-loaded oily nanosuspension could be a promising treatment option for veterinary infections against trypanosomiasis.

Gene expression study to elucidate the anti-trypanosomal activity of quinapyramine methyl sulphate (QPS).

The kinetoplastid protozoan parasite, Trypanosoma evansi causes a fatal disease condition known as Surra in equines throughout the globe. Disease condition being acute in nature, entrust a huge economic and health impact on the equine industry. Till date, quinapyramine methyl sulphate (QPS) is the first line of treatment and a panacea for the T. evansi infection in equines. Still after the >70 years of its discovery, there is no clue about the mode of action of QPS in T. evansi. The establishment of in vitro cultivation of T. evansi in HMI-9 media has provided opportunity to study the alteration in mRNA expression of parasite on exposure to the drug. With this research gap, the present study aimed to investigate the relative mRNA expression of 13 important drug target genes to elucidate the anti-trypanosomal activity of QPS against T. evansi. The IC50 of QPS against a pony isolate of T. evansi was determined as 276.4 nM(147.21 ng/ mL) in the growth inhibitory assay. The in vitro cultured T. evansi population were further exposed to IC50 of QPS and their relative mRNA expression was studied at 12 h, 24 h and 48 h interval.The mRNA expression of several genes such as hexokinase, trypanothione reductase, aurora kinase, oligopeptidase B and ribonucleotide reductase II were found refractory (non-significant, p > 0.1234) to the exposure of QPS. Significant up-regulation of trans-sialidase (p < 0.0001), ESAG8 (p < 0.0021), ribonucleotide reductase I (p < 0.0001), ornithine decarboxylase (p < 0.0001), topoisomerase II (p < 0.0021) and casein kinase I (p < 0.0021) were recorded after exposure with QPS. The arginine kinase 1 and calcium ATPase I showed highly significant (p < 0.0001) down-regulation in the drug kinetics. Therefore, the arginine kinase 1 and calcium ATPase I can be explored further to elucidate the trypanocidal activity of QPS. The preliminary data generated provide the potential of arginine kinase 1 and calcium ATPase I mRNA mediated pathway of trypanocidal action of QPS. Further, transcriptomics approach is required to investigate the possible mechanism of action of drugs at molecular level against the targeted organism.

Preparation and Evaluation of Quinapyramine Sulphate-Docusate Sodium Ionic Complex Loaded Lipidic Nanoparticles and Its Scale Up Using Geometric Similarity Principle.

The objective of the present work is to prepare and evaluate ionically complexed Quinapyramine sulphate (QS) loaded lipid nanoparticles and its scale up using geometric similarity principle. Docusate sodium (DS), at a molar ratio of 1:2 of QS to DS, was used to prepare hydrophobic Quinapyramine sulphate-Docusate sodium (QS-DS) ionic complex. Based on the difference in total solubility parameter and polarity of QS-DS complex and different lipids, precirol was selected as a lipid for the preparation of lipidic nanoparticles. The particle size, zeta potential, and % entrapment efficiency (%EE) of QS-DS ionic complex loaded solid lipid nanoparticles (QS-DS-SLN) was found to be 250.10 ± 26.04 nm, -27.41 ± 4.18 mV and 81.26 ± 4.67% respectively. FTIR studies confirmed the formation of QS-DS ionic complex. DSC and XRD studies revealed the amorphous nature of QS in QS-DS-SLN. The spherical shape of nanoparticles was confirmed by scanning electron microscopy. QS-DS-SLN showed sustained release of QS for up to 60 h. No significant difference was observed in particle size, zeta potential, and % entrapment efficiency of pilot-scale batch prepared by using rotational speed of 700 rpm. In conclusion, ionic complexation approach can be used to increase % EE of charged drugs into lipid nanoparticles.

Treatment Efficiency of Combination Therapy With Diminazene Aceturate and Quinapyramine Sulfate in a Horse With Dourine.

Dourine is a lethal protozoan disease of equids, and it is caused by Trypanosoma equiperdum infection via coitus. To date, treatment strategies against the dourine are not recommended because of the frequent relapses; therefore, the World Organisation for Animal Health recommends the stamping-out policy for the control of dourine. Our previous studies have revealed a number of horses with dourine in Mongolia that is the fifth largest horse-breeding country. It is difficult to apply the stamping-out policy for cases of dourine in Mongolia because of an inadequate livestock guarantee system. Therefore, the development of effective treatment measures is an urgent need. In this study, an 8-year-old stallion was definitely diagnosed with dourine based on clinical signs, molecular analysis, and microscopic examination of trypanosomes. Combination therapy with diminazene aceturate and quinapyramine sulfate was applied. Before the treatment, the characteristic clinical signs of dourine were observed, and trypanosomes were detected in the urogenital tract mucosal swab samples by microscopic examination and polymerase chain reaction (PCR). Moreover, positive serological results were obtained. After the treatment, we observed an improvement in the health of the treated horse and no trypanosome infection in its urogenital tract by microscopic examination and PCR. Moreover, serological tests showed seronegative results. The horse has showed no relapse for at least 2.5 years after the treatment, and its reproductive ability has improved. Our result suggests that trypanosomes did not invade cerebrospinal fluid when we started the therapy. In conclusion, the combination therapy has therapeutic potential against dourine at an early phase.

Biocompatibility and Targeting Efficiency of Encapsulated Quinapyramine Sulfate-Loaded Chitosan-Mannitol Nanoparticles in a Rabbit Model of Surra.

Quinapyramine sulfate (QS) produces trypanocidal effects against the parasite Trypanosoma evansi but is often poorly tolerated and causes serious reactions in animals. The encapsulation of QS in chitosan-mannitol to provide sustained release would improve both the therapeutic effect of QS and the quality of life of animals treated with this formulation. QS was encapsulated into a nanoformulation prepared from chitosan, tripolyphosphate, and mannitol nanomatrix (ChQS-NPs). ChQS-NPs were well ordered in shape, with nanoparticle size, as determined by transmission electron microscopy and atomic force microscopy. Our research revealed dose-dependent effects on biosafety and DNA damage in mammalian cells treated with ChQS-NPs. ChQS-NPs were absolutely risk-free at effective as well as many times higher doses against T. evansi ChQS-NPs were effective in rabbits, as they killed the parasites, relieving the animals from the clinical symptoms of the disease. The extent of this protection was similar to that observed with the conventional drug at higher dosages (5 mg QS/kg of body weight). ChQS-NPs are safe, nontoxic, and more effective than QS and offer a promising alternative to drug delivery against surra in animal models. ChQS-NPs may be useful for the treatment of surra due to reduced dosages and frequency of administration.

Early detection of Trypanosoma evansi infection and monitoring of antibody levels by ELISA following treatment.

In present communication, we report an outbreak of Trypanosoma evansi in equine herd n = 30 (horse and mules) which, were reared in fly proof stables as well as in open paddock maintained under semi-intensive system of management, and its effective control using trypanocidal drug. The infection was monitored by antibody ELISA up to 180 days post-treatment (PT). A total of 8 out of 14 equines (57.14 %) which were maintained only in open paddocks were found positive with T. evansi infection parasitologically. The infected animals were treated with quinapyramine methyl sulphate and chloride combination administered at the prescribed dose rate on 3rd day of screening. The parasite could not be detected from any treated animals from day-3 PT up to 6 month. Further, we also could not observe relapse of infection, neither in treated group nor in equine herd maintained at the farm. Sero-conversion was observed in all eight animals by 10th day of screening, indicating that immune response was due to recent infection as the animals became chronologically positive. The antibody titre reached at the peak by 10-14th day in all infected animals, and started declining by 17th day of screening, further reached to near cut off level by 180 days. Since, antibodies persisted up to 6 month PT and antibody detection assays are not able to differentiate between current and past infections in treated cases. The detection of circulating antigen assay and parasitological techniques in combination may be performed for effective diagnosis and management of T. evansi infection.

Quinapyramine sulfate-loaded sodium alginate nanoparticles show enhanced trypanocidal activity.

AIM: To reduce the dose, toxic effects and to ensure sustained release of quinapyramine sulfate (QS), a highly effective drug against Trypanosoma evansi. MATERIALS & METHODS: QS-loaded sodium alginate nanoparticles (QS-NPs) were formed by emulsion-crosslinking technology using dioctyl-sodium-sulfosuccinate and sodium alginate. The formulation was characterized for size, stability, morphology and functional groups by a zetasizer, scanning electron microscopy, atomic force microscopy, transmission electron microscopy and Fourier transform infrared spectroscopy. In vitro safety and toxicity studies were performed by metabolic assay in Vero cell lines, and in vivo efficacy was evaluated in mice. RESULTS: QS-NPs were <60 nm with 96.48% entrapment efficiency and 3.70% drug loading. The formulation showed an initial burst effect followed by slow drug release in accordance with quasi-Fickian Higuchi diffusion mechanism. QS-NPs were much less toxic and able to clear the parasite at a much lower concentration than QS. CONCLUSION: The QS-NPs synthesized are safe, less toxic and highly effective compared with QS.