No abstract

No abstract

Few chemotherapeutic agents are available for the medical management of hydatid disease caused by the parasite Echinococcus granulosus. In order to test the potential of oxfendazole for the treatment of infection with this parasite, nine infected goats and four sheep were given oxfendazole twice weekly at a dose of 30 mg/kg of body weight for 4 weeks and monitored by ultrasound for an additional 4 weeks. Efficacy was finally evaluated by postmortem examination, including determination of protoscolex viability and cyst wall histology. In treated animals, protoscolices were dead or absent in 97% of cysts from oxfendazole-treated animals compared to 28% of cysts from untreated control animals. On postmortem examination, 53% of cysts from treated animals were found to be grossly degenerate. A sample of those cysts that appeared potentially viable all demonstrated evidence of severe damage to the cyst wall. By light microscopy, cysts showed severe disorganization of the adventitial layer with invasion of inflammatory cells and in some cases frank necrosis with no apparent adventitial layer. The follow-up period for assessment of the drug’s ability to cause complete degeneration and resorption of cysts was relatively short. This study, however, indicates that oxfendazole is at least as effective as and is easier to administer than albendazole for the treatment of hydatid disease.

In Turkana, Kenya, a prevalence of hydatidosis of nearly 10% has been recorded among the pastoralists yet their livestock have a much lower prevalence of the disease. The present study investigated the release from dogs and subsequent survival of Echinococcus eggs in Turkana huts, water-holes and in the semi-arid environment. The results were compared with the survival of eggs of Taenia hydatigena and T. saginata. The study was repeated under the cooler and moister conditons found in Maasailand where livestock have a greater incidence of hydatid disease than in Turkana but where the incidence in man is ten times lower. The average number of Echinococcus eggs per proglottid is 823. Nine percent of these remain in proglottids 15 minutes after release from a dog and the released eggs lose their viability in less than two, 48 and 300 hours in the sun, huts and water in Turkana respectively; the major influencing factor being temperature. The greater survival of eggs in the houses, coupled with the fact that dogs congregate for most of the day in the small houses facilitating a close man:dog contact, provide ideal conditions for the trasmission of the parasite to man. The hostile environmental conditions and lack of contact between dogs and livestock contributes to the lower infection rate in livestock. Conversely in Maasailand, Echinococcus eggs survive in the environment for longer than three weeks and in addition, dogs are used for herding. This partly explains the higher infection rate among Maasai livestock but the low human infection rate remains arcane and requires further study. The rapid mortality of the majority of Echinococcus eggs in Turkana suggests that control measures aimed at dog control and a decreased man:dog contact should have a profound effect on the incidence of the disease in an area intrinsically unsuitable for the parasites' survival.

Inflammation and pain are devastating conditions characterizing many diseases. Their manifestation ranges from mild body discomfort, to a debilitating experience, which may culminate in organ failure or death. In conventional medicine, corticosteroids, nonsteroidal anti-inflammatory drugs, opioids, and adjuvants are utilized to manage symptoms related to pain and inflammation. Despite their reported successes, these agents are only palliative, debatably inaccessible, unaffordable, and cause many undesirable side effects. As a result, the search for alternative and complementary therapies is warranted. Medicinal plants have been intensively utilized by humans for a long time to treat various ailments. In spite of their reported efficacies, empirical scientific data supporting their healing claims is scanty. P. thonningii (Schumach.) has been used in African traditional medicine, especially by traditional herbalists in Nigeria and Kenya, to treat conditions associated with inflammation. Even though analgesic, anti-inflammatory, and toxicity studies have been performed on leaf extracts, and some of their isolated compounds in Nigeria, there is scanty data supporting the use of stem bark extracts, which are commonly utilized in Kenya for pain, and inflammation management. Moreover, scientific data regarding safety and toxicity of the stem bark extracts of P. thonningii utilized in Kenya by traditional herbalists are inadequate. Based on this background, acute oral toxicity evaluation of the aqueous and methanolic stem bark extracts of P. thonningii, in Swiss albino mice, was performed according to the OECD/OCDE (2008) guidelines. Anti-inflammatory activities were investigated using the xylene-induced ear oedema in mice, whereas analgesic activities were examined following the acetic acid-induced writhing technique. The acute oral toxicity data was analyzed, and interpreted according to the OECDE (2008) guidelines. Anti-inflammatory and analgesic activities data were tabulated on MS Excel, and exported to GraphPad Prism (v8.3). Descriptive statistics were computed, and expressed as mean ± SEM. Thereafter, One-Way ANOVA followed by Tukey’s test was performed. p<0.05 was considered statistically significant. All the studied plant extracts had LD50 values > 2000 mg/kg bw, and were hence deemed to be nontoxic according to OECD/OCDE document no. 425. The results showed that the acetic acid-induced writhing frequency in mice administered the aqueous stem bark extract of P. thonningii, at a dose of 500 mg/kg bw, was not significantly different from that recorded for mice which received the reference drug (acetylsalicylic acid 75 mg) (p>0.05). Additionally, at all the studied extract doses, significantly lower acetic acid-induced writhing frequencies were recorded in mice that received the aqueous stem bark extract of P. thonningii, compared with the writhing frequencies in mice that received the methanolic extract of the same plant (p<0.05). On the other hand, the aqueous stem bark extract of P. thonningii, at doses of 100 mg/kg bw and 500 mg/kg bw, and the methanolic stem bark extract of the same plant, at a dose level of 500 mg/kg bw, exhibited significantly higher percentage inhibitions of xylene-induced oedema than the percentage inhibitions shown by the reference drug (dexamethasone 1 mg/kg bw) (p<0.05). Generally, the aqueous stem bark extract of P. thonningii, at all the studied dose levels, caused significantly higher inhibitions of xylene-induced ear oedema in mice, compared with the percentage inhibitions shown by methanolic stem bark (p<0.05). Therefore, the aqueous, and methanolic stem bark extracts of P. thonningii, grown in Kenya, possess peripheral analgesic and anti-inflammatory activities in Swiss albino mice. Hence, they have a potential of offering safe analgesic, and anti-inflammatory compounds. Further studies aimed at isolating, elucidating, and characterizing bioactive components from the studied extracts are recommended. Moreover, specific mode(s) through which these extracts exert the reported bioactivities should be established. Further toxicological investigations involving the studied plant extracts are encouraged to fully establish their safety.