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Abstract Trichinellosis is a parasitic zoonosis caused by nematodes belonging to the Trichinella genus. Humans become infected after eating raw or undercooked meat that contains infective larvae. Despite the fact that this happens by chance, trichinellosis is believed to affect roughly 00 million people worldwide. Furthermore, it can occur in largescale outbreaks impacting tens of thousands of people. Trichinellosis has been labelled an emerging or re-emerging disease in various countries as a result of rising living levels and changing food patterns. Trichinellosis mostly affects muscles, however it can potentially result in catastrophic consequences including myocarditis and encephalitis. The effectiveness of chemotherapy with albendazole or mebendazole, for example, is mostly determined by the timing of administration; treatment only at the earliest stage of infection gives good results. The majority of cases are discovered some weeks after infection, after the larvae have established themselves in the muscles. Several studies have sought to identify new alternative drugs to treat trichinellosis. The present study aimed to assess the in vitro effects of nifedipine; a calcium channel blocker, and the herbal agent C. coronarium as therapeutic repurposed agents for the treatment of different developmental stages of T. spiralis. T. spiralis was kindly provided by Parasitology Department, TBRI from laboratory bred infected Swiss albino mice. Muscle larvae were recovered from the carcasses of infected mice after 22 dpi by the artificial digestion method according to standard procedures. Adult worms were obtained from the small intestine of the infected mice 2 dpi previously infected with T. spiralis ML. The parasites were incubated in RPMI-0311 containing 015 fetal calf serum and antibiotics (311 U/ml penicillin and 311 μg/ml streptomycin) at 234C and 25 CO3. Albendazole was used in concentrations of 111, 311, 011, 21, 32μg/ml. Nifedipine was prepared from Epilat capsules (01 mg) obtain concentrations of 03.2, 3.32, 2.032, 0.23, 1.38 μg/ml. C. conornarium was extracted from air dried flowers in methanol at room temperature to obtain concentrations of 111, 311, 011, 21, 32 μg/ml. The current results showed that the effect of different studies drugs was time and dose dependent. At 32 μg/ml, albendazole showed a statistically significant effect after 23hrs. It also killed all larvae after 18 hrs in concentrations starting from 011 μg/ml. The statistically significant larvicidal effect was evident from the first hr of exposure at concentration of 011 μg/ml. The LC21 of albendazole was calculated to be 80.32 μg/ml. A statistically significant larvicidal effect of nifedipine was obtained at a concentration of 1.38 μg/ml after 1 hrs. It killed all larvae after 33 hrs in concentrations starting from 2.032 μg/ml. The LC21 of nifedipine was calculated to be 0.31 μg/ml. C. coronarium killed all larvae only at concentration of 111 μg/ml after 23hrs. It had the weakest effect. A statistically significant difference was recorded initially at 311 μg/ml after 18 hrs. It was noticed that it needed at least 18 hrs to exert its effect. Chapter Six Summary, Conclusion and Recommendations 31 SEM examination of the tegument of T. spiralis ML of the control untreated groups showed the typical coiling behaviour and the characteristic pattern of tegument with longitudinal ridges and transverse creases. Destruction of the tegument of all treated T. spiralis ML was evident with multiple degenerative changes. The destruction was more obvious in those treated by albendazole. The tegument of treated ML showed considerable damage as some areas illustrated marked swelling with loss of the normal creases, ridges and annulations of the tegument. Occurrence of blebs, multiple vesicles and focal sloughing was also observed. As regard the effects of the all studies tested drugs on adult worms were time and dose dependent. At low doses 32, 21 μg/ml, albendazole showed non-statistically significant effect even after 33 hrs. The statistically significant effect was evident starting from 1 hrs of exposure at concentration of 011 μg/ml. It killed all worms after 31 hrs in concentrations starting from 311 μg/ml. The LC21 of albendazole was calculated to be 82.33 μg/ml. The effect of nifedipine was time and dose dependent. A statistically significant effect was obtained at a concentration of 0.23 μg/ml after 31hrs. It killed all worms after 1 hrs in concentration starting from 3.32 μg/ml. The LC21 of nifedipine was calculated to be 0.83 μg/ml. C. coronarium extract caused death all adult worms at high concentrations (411 μg/ml and 211 μg/ml after 44 hrs). A statistically significant difference was recorded initially after incubation at 611 μg/ml for 44 hrs but It had the weakest effect. The LC41 of C. coronarium was calculated to be 642911μg/ml. SEM examination of the tegument of control untreated T. spiralis adult worms showed normal morphology with preserved tegument and normal appearance of the hypodermal gland opening. Destruction of the adult worms’ tegument in all treated adult worms was evident with more destruction in those exposed to ABZ than those exposed to NIF and C. coronarium. The tegument morphological changes were in the form of marked swellings or sometimes collapse of the whole body with disappearance of internal contents. Sloughing of some areas of the tegument and the appearance of cauliflower masses were also observed. |