Antidiabetic, Antioxidant and Anti-Inflammatory Activities of Residual Aqueous Fraction of Ethulia conyzoides in Induced Type 2 Diabetic Rats

Oxidative stress and inflammation have been proven to be implicated in the pathogenesis of type 2 diabetes. Recent studies showed that Ethulia conyzoides had in-vitro antioxidant activity. This study investigated the in-vivo antidiabetic, antioxidant, and anti-inflammatory potential of the residual aqueous fraction of Ethulia conyzoides in type 2 diabetic-induced male Wistar rats. Sub-acute antidiabetic studies were done with varying doses (100, 200, and 400 mg/kg body weight) of residual aqueous fraction for 21 days. Blood glucose levels, serum insulin, and in vivo antioxidant and pro-inflammatory cytokines-tumour necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) -were measured at the end of the treatment. When rats were given different concentrations of residual aqueous fraction, there was a significant (p < 0.05) reduction in blood glucose, malondialdehyde (MDA), IL-1β, and TNF-α levels, as well as a significant (p < 0.05) increase in SOD (superoxide dismutase), catalase and insulin levels when compared to the diabetic control group. Furthermore, the 400 mg/kg body weight dosage concentration was found to be the most effective. This result suggests that the residual aqueous fraction of Ethulia conyzoides possesses significant antidiabetic, antioxidant and anti-inflammatory activities.

Kolaviron pre-treatment suppresses 7, 12 dimethylbenzanthracene-induced alterations in estrogen receptor-α, CYP 1A1, oxidative stress and inflammation in female Wistar rats

Due to the need to develop locally available, cheaper, and efficacious treatment regimens for breast cancer, the chemopreventive effect of kolaviron (KV), an extract of Garcinia kola seeds was examined. Fifty (50) female Wistar rats (120-180 g) were assigned to five groups (control group, 7, 12 dimethylbenzanthracene [DMBA] groups, tamoxifen group) of 10 rats each. They were pre-treated with KV thrice a week for four weeks except control. Estrogen receptor-α (ER-α) levels were determined in the pre-treated rats before induction of mammary carcinogenesis. After the four weeks pre-treatment period, 80 mg/kg of DMBA was used for induction. A hundred and fifty (150) days after induction, the rats were sacrificed humanely. Significantly higher levels of ER-α, formation of lobular neoplastic cells, epithelial hyperplasia, lymphocyte infiltration, increased cytokines (interleukin-6 [IL-6] and tumor necrosis factor-α [TNF-α]), CYP1A1 activity and malondialdehyde (MDA) with a corresponding decrease in superoxide dismutase (SOD), catalase and glutathione peroxidase were observed in DMBA-induced rats. Pre-treatment with KV at 200 mg/kg body weight significantly (p < .05) decreased ER-α levels by 19.01% and 37.52%, [IL-6] by 36.37% and 20.55%, TNF-α by 42.2% and 12.33% in serum and mammary tissue respectively. Also, a significant (p < .05) decrease in serum CYP1A1 activity, MDA with concomitant increase in SOD, catalase and glutathione peroxidase activities were observed in serum and mammary tissue respectively. Collectively, the results suggest that KV could be further explored in targeting chemoprevention of DMBA-induced mammary damage. PRACTICAL APPLICATIONS: Garcinia kola is widely cultivated in West and Central Africa with kolaviron (KV) as its major constituents. The seeds which have a bitter astringent taste are widely consumed by people in the region. Locals claim that consumption of the seeds provides relief for the management of several ailments including cancer. However, scientific investigations that provide a basis for these claims are still needed. This study provides evidence that points to the ameliorative potential of KV on breast cancer model. The results will be beneficial to local communities who hitherto had no knowledge on the potential of G. kola in chemoprevention. The results from this study will also attract further research attention from the international scientific community to examine the anti-cancer benefits of G. kola. This will also be beneficial to the global community due to the increasing number of breast cancer cases recorded annually.

Abstract PO-156: Emerging demographic changes of first eighteen (18) most common cancers among West Africans in Zaria Nigeria (1972 – 2019)

The African continent is facing enormous challenges from cancer crisis, and the lack of reliable population database on cancer incidence and mortality hinders high quality decision on prevention and management modalities. The objective of this study is to analyze the trend of malignant tumors in a population of rural Africans attending Ahmadu Bello University Teaching (ABUTH) Hospital Zaria, Nigeria with particular emphasis on the first eighteen (18) frequently diagnosed cancers over a period of 46 consecutive years (1972 - 2019) excluding the year 1988. Histologically diagnosed cancers from the population-based cancer registry of the ABUTH Zaria were included in this study. There were 19, 884 histologically diagnosed cancers over 46 years in ABUTH Zaria with the following in descending order: Cervical cancer 2,335 (12%, [squamous cell carcinoma = 1, 809; others = 529]), Breast cancer 1,982 (10% [invasive ductal carcinoma = 1,589; others = 393]), Lymphoma 1,927 (10% [non–Hodgkin’s lymphoma = 1,335; Hodgkin’s lymphoma = 492]), Sarcomas 1,177 (6% [Kaposi sarcoma = 296; Rhabdomyosarcoma = 172; Osteosarcoma = 166; Dermatofibrosarcoma = 102; Fibrosarcoma = 83; others = 358]), Prostate cancer 1,073 (5%), Colorectal cancer 816 (4% [other adenocarcinomas = 666, mucinous adenocarcinoma = 93; signet ring cell adenocarcinoma =14, others = 43]), Non- melanoma skin cancer 717 (4%), Eye/ Orbit cancer 537 (3% [retinoblastoma = 302; squamous cell eye cancer = 153; others = 82]), Bladder cancer 515 (3%), Liver cancer 481 (2% [primary liver cell carcinoma = 399; others = 79]), Salivary gland cancer 398 (2%), Melanoma 394 (2%), Ovarian cancer 278 (1%), Nasopharyngeal cancer 235 (1%), Kidney cancer 201 (1% [nephroblastoma = 113; renal cell carcinoma = 77; others = 11]), Esophageal cancer 145 (1%), Thyroid cancer 122 (1%), Pancreatic cancer 60 (0.29%) and Others 7,053 (33%). This total, exclude referred cancer cases to oncology department of ABUTH from other hospitals across the country which makes up 60% of cancer cases treated in institution and a handful of clinically diagnosed cases. The results show unusual change in trend with: 2 fold increase for cervical cancer, 6 fold increase for Breast cancer, 8 fold increase for Prostate cancer, 3 fold increase for colorectal cancer; 6 fold increase for Pancreatic cancer, 13 fold increase for Nasopharyngeal cancer and 16 fold increase for Oesophageal cancer when comparing incidence of cancer from 2011-2019 with 1972-1980. However, the results show 12 fold decrease for Liver cancer and 3 fold decrease each for Lymphoma and Non-melanoma skin cancer when comparing cancer cases from 2011-2019 with 1972 - 1980. Understanding the phenomenon behind the rapid change in trend of different cancer types in sub Saharan Africa may contribute to addressing cancer challenges and better policy decision on cancer in the continent.

Citation Format: Faruk Mohammed, Abdulmumini Hassan Rafindadi, Sani Ibrahim, Yawale Iliyasu, Sirajo Mohammed Aminu, Ahmed Adamu, Adamu Abdullahi, Aishatu Maude Suleiman, Abdullahi Mohammed, John Idoko, Abdulkadir Lawal Rafindadi, Danladi Amodu Ameh, Bello Kumo, Ahmad Bello, Abdullahi Jubril Randawa, Usman Mohammed Aminu, Muhammad Manko, Tajudeen Olasinde, Mohammed Dauda Maigatari, Ahmed Mai, LMD Yusuf, Abdullahi Alfa Mohammed, Yahaya Ukwenya, Oguntayo Olanrewaju Adekunle, Maitama Yusuf Hussaini. Emerging demographic changes of first eighteen (18) most common cancers among West Africans in Zaria Nigeria (1972 – 2019) [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-156.

Abstract 2638: Overexpressions of cortisol, annexin V and Lost in expression of PD-L1 and DARC proteins are associated with aggressive prostate cancer phenotypes in Black men: A CaPTC Cohort Study

Prostate cancer (CaP) is the most common male gender cancer and present with a 5-year prevalence, incidence and mortality rate in Nigerian Black men. There is disproportionate prevalence and poor understanding of CaP in Black men globally. The Prostate Cancer Transatlantic Consortium (CaPTC) has documented significant CaP burden among Nigerian black men in Nigeria and in the Diaspora. Notably, African ancestry is one of the most important risk factors of CaP globally. Increased levels of cortisol, a stress-related catabolic hormone is significantly associated to prostate specific antigen and poor prognosis in prostate cancer patients. Cortisol causes degradation of muscle proteins into amino-acids. Amino acids such as leucine, serves as a source of fuel for aggressive prostate cancer cells in a Warburg effect model through the L-amino acid transporters (LATs). The annexins are calcium and phospholipid binding proteins implicated in cancer development and progression. Overexpression of annexin 1 is one of the mechanisms by which cortisol inhibit inflammation. Annexin V has a high affinity to phosphatidylserine and play important role of inhibiting engulfment of apoptotic cells by macrophages to increase the immunogenicity of tumor cells undergoing apoptosis. PD-L1 is an important membrane-bound costimulatory molecule that inhibits immune responses through its receptor, PD-1. Overexpression of PD-L1 results to cancer cells aggressively evading the host immune system. The Duffy Antigen/Receptor for Chemokines (DARC) is a 7-transmembrane protein atypical chemokine receptor expressed on erythrocytes and vascular endothelial cells that binds to and clears angiogenic chemokines. Expression pattern of DARC is associated to cancer growth and metastasis. In this study, we report the expression pattern of tissue Cortisol, Annexin V, PD-L1 and DARC proteins in relationship to Gleason score in Nigerian Black men with Prostate cancer using immunohistochemistry and immunofluorescence. In addition, we assessed salivary cortisol levels by enzyme immunoassay and physical activity by a standardized CaPTC-AC3-MADCaP (C.A.M) CaP measures from 500 subjects recruited by via CaPTC cohort. Results showed significant expression of tissue and salivary cortisol in the CaP patients compared to the normal subjects (p &gt; 0.05). The Tissue cortisol protein expression was higher in CaP cases with Gleason score 8. There was significant overexpression of Annexin protein in virtually the prostate cancer samples studied. We found a negative expression of PD-L1 and DARC proteins in all the CaP tissues studied. Cortisol and Annexin may serve as an important biomarker for prostate cancer diagnosis and prognosis in Nigerian Blacks.

Citation Format: Faruk Mohammed, Folakemi T. Odedina, Sani Ibrahim, Abdulmumini Hassan Rafindadi, Ahmed Adamu, Abdullahi Adamu, Ahmad Bello, Surajo Mohammed Aminu, John Idoko, Aishatu Maude Suleiman, Solomon O. Rotimi, Ernie Kaninjing, Getachew A. Dagne, Clayton Yates, Yawale Iliyasu, Nissa Askins, Iya Eze Bassey, Renee Reams, Abdullahi Mohammad, Hussaini Yusuf Maitama, Dauda Maigatari, Mohammed Sani Shehu, Cheh Augustine Awasum, Abdulkadir Lawal Rafinadadi, Danladi Amodu Ameh, Serah Adewunmi, Ruth Agaba, Haruna Mohammad Muktar, Ahmad Mai, Saad Aliyu Ahmed, Ahmad Bello Kumo, Kasimu Umar Adoke, Ahmad Tijjani Lawal, Ahmad Muhammad, Omolora Fatiregun, Sunday Atawodi, Shehu Akuyam, Yusuf Abdulrashid, Mubarak Liman, Aliyu Muhammad, Abidemi Omonisi, Rebecca Gali, Hassan Dogo, Nkegoum Blaise, Anthonia Sowunmi, Titilola Akinremi, Emeka J. Iweala, Jigo Dangude Yaro, Badejo Adebukola Catherine, Akinwumi Oluwole Komolafe. Overexpressions of cortisol, annexin V and Lost in expression of PD-L1 and DARC proteins are associated with aggressive prostate cancer phenotypes in Black men: A CaPTC Cohort Study [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2638.

An analysis of dietary fiber and fecal fiber components including pH in rural Africans with colorectal cancer

Background/Aims

Colorectal cancer (CRC) is now a major public health problem with heavy morbidity and mortality in rural Africans despite the lingering dietary fiber-rich foodstuffs consumption. Studies have shown that increased intake of dietary fiber which contribute to low fecal pH and also influences the activity of intestinal microbiota, is associated with a lowered risk for CRC. However, whether or not the apparent high dietary fiber consumption by Africans do not longer protects against CRC risk is unknown. This study evaluated dietary fiber intake, fecal fiber components and pH levels in CRC patients.

Methods

Thirty-five subjects (CRC=21, control=14), mean age 45 years were recruited for the study. A truncated food frequency questionnaire and modified Goering and Van Soest procedures were used.

Results

We found that all subjects consumed variety of dietary fiber-rich foodstuffs. There is slight preponderance in consumption of dietary fiber by the control group than the CRC patients. We also found a significant difference in the mean fecal neutral detergent fiber, acid detergent fiber, hemicellulose, cellulose and lignin contents from the CRC patients compared to the controls (P<0.05). The CRC patients had significantly more fecal pH level than the matched apparently healthy controls (P=0.017).

Conclusions

The identified differences in the fecal fiber components and stool pH levels between the 2 groups may relate to CRC incidence and mortality in rural Africans. There is crucial need for more hypothesis-driven research with adequate funding on the cumulative preventive role of dietary fiber-rich foodstuffs against colorectal cancer in rural Africans “today.”

Abstract A19: Dietary-fiber and fecal fiber contents including pH in rural Africans with colorectal cancer

Studies have shown improved/increased intake of dietary fiber and low fecal pH are associated with a lowered risk for colorectal cancer. This study aimed to compare dietary fiber intake, fecal neutral detergent fiber (NDF) content, acid detergent fiber (ADF), cellulose, hemicellulose, lignin and fecal pH level of colorectal cancer patients and matched apparently healthy control group in rural Africans in Zaria, Nigeria. Twenty-one subjects of mean age 44.7 years who are diagnosed with colorectal cancer by histology and 14 apparently healthy matched control groups with mean age 45.2 years were recruited for this study. A predefined semi structured food frequency questionnaire (FFQ) was used to access the dietary fiber intake by the subjects. The fecal NDF content was analyzed by extracting 1 g of fecal sample with a mixture of ethanol/ether and refluxed with decalin and sodium sulphite. The extract was suctioned and washed with acetone to yield the total NDF. The NDF was refluxed with an acid detergent solution and dried overnight to yield the ADF. The differences in the NDF and ADF gave the total hemicelluloses. The differences in the weight of the ADF post-treatment with permanganate solution yielded the total lignin. The differences in weight of the permanganate residue post-treatment with 72% Sulphuric acid gave the cellulose content. A pH meter calibrated with buffers of pH 4 and 7 was used to measure the fecal pH of all the subjects. Results from the FFQ show all subjects consumed variety of dietary fiber food in significant amount. However, there was a significant difference in the fecal NDF, ADF, hemicellulose, lignin and cellulose contents from the colorectal cancer patients when compared with the control group (p &lt;0.05). So also was there a significant difference in fecal pH between the two groups (p &lt;0.05). Consumption of dietary fiber rich foodstuffs alone may not be adequate for prevention against colorectal cancer incidence in some rural Africans in Zaria. There is a need to look into other associating factors which, might have been contributing to colorectal cancer incidence/increase in rural African population.

Citation Format: Mohammed Faruk, Sani Ibrahim, Ahmed Adamu, Abdulmumini Hassan Rafindadi, Yahaya Ukwenya, Yawale Iliyasu, Abdullahi Adamu, Mohammed Sani Shehu, Danladi Amodu Ameh, Sirajo Mohammed Aminu, Saad Aliyu Ahmed, John Idoko, Atara Ntekim, Aishatu Maude Suleiman, Khalid Zahir Shah, Kasimu Umar Adoke. Dietary-fiber and fecal fiber contents including pH in rural Africans with colorectal cancer [abstract]. In: Proceedings of the AACR International Conference: New Frontiers in Cancer Research; 2017 Jan 18-22; Cape Town, South Africa. Philadelphia (PA): AACR; Cancer Res 2017;77(22 Suppl):Abstract nr A19.

Abstract B71: First ten malignancies by ranking from a population of rural Africans in Zaria, Nigeria: A fourteen years review and report

Every environment is noted for its variability in incidences of various malignancies and subtypes. The objective of this study is to analyze the trend of malignant tumors in a population of rural Africans attending Ahmadu Bello University Teaching Hospital Zaria, Nigeria with particular emphasis on the first ten most frequently diagnosed cancers over a period of 14 consecutive years (2001-2014).

Histologically diagnosed cancers in the various cancer registries of the ABUTH Zaria were included in this study. The ten most commonly presenting cancers were extracted and their demographic characteristics and other relevant clinical data documented using a standardized questionnaire. The data obtained were analyzed using SPSS software version 20.0.

There were 6,553 histologically diagnosed cancers over 14 years in Ahmadu Bello Unibersity Teaching Hospital Zaria with the following in descending order: Cervical cancer 1042 (15.90%), Breast cancer 788 (12.02%), Prostate cancer 496 (7.56%), Colorectal cancer 360 (5.49%), Lymphoma 306 (4.66%), Eye/orbit cancer 170 (2.59%), Bladder cancer 169 (2.45%), Nasopharyngeal cancer 139 (2.12%), Ovarian cancers 94 (1.43%), and Liver cancer 52 (0.79%).

Cervical cancer tops the list as the most frequently diagnosed cancer however, this should be noted that it is a cancer exclusive to females so also breast cancers though rarely males may present with breast cancer. Prostate cancer is a male exclusive disease therefore the percentage would have been higher if the diagnosis would have excluded the females. Of the ten most frequently diagnosed cancers, liver cancer is the tenth despite the fact that complications of viral hepatitidis are known to facilitate liver carcinogenesis and the prevalence of hepatitis C and B in the Nigerian population is 5 and 20 respectively.

Citation Format: Abdulmumini Hassan Rafindadi, Surajo Mohammed Aminu, Mohammed Faruk, Yawale Iliyasu, Abdullahi Mohammed, Sani Ibrahim, Ahmed Adamu, Mohammed Sani Shehu, Abdullahi Jubril Randawa, Adamu Abdullahi, Saad Aliyu Ahmed, Maitama Yusuf Hussaini, Danladi Amodu Ameh, Ukwenya Yahaya, John Idoko, Oguntayo Olanrewaju Adekunle, Almustapha Aliyu Liman, Abdulkadir Lawal Rafindadi, Aisha Maude Suleiman, Jigo Dangude Yaro, Ahmad Bello, Bello Kumo. First ten malignancies by ranking from a population of rural Africans in Zaria, Nigeria: A fourteen years review and report. [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr B71.

Hepatotoxic effects of chloroform extract of Artemisia macivera Linn in rats following intraperitoneal administration of different subchronic doses

The possible hepatotoxic effects of chloroform extract of Artemisia maciverae was evaluated biochemically and histologically using male Swiss albino rats, randomly assigned into four groups of 24 animals each. The groups (control, 50, 100 and 200 mg/kg body weight) were treated for 60 days and then monitored for another 30 days before sacrifice. Alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, bilirubin (total and direct), total protein and albumin were assessed colorimetrically, while tissue specimens were subjected to histological examination following standard hematoxyline-eosin staining techniques. After 1 week of treatment, the extract caused statistically significant elevation in levels of serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase and bilirubin (total and direct), while there was significant (p < 0.05) decrease in the levels of serum total protein and albumin at the onset of treatment when compared with the control. These abnormalities in the levels of serum biochemical parameters were spontaneously corrected within 2 weeks of treatment. Similarly, histological assessment showed severe hepatic tissue injuries after 1 week, but these organs recovered spontaneously by the second week of treatment. The results indicate that long-term exposure to therapeutic doses of chloroform extract of A maciverae is relatively safe, but high dose exposure may result in hepatocellular injury.

Bioassay-guided fractionation and in vivo antiplasmodial effect of fractions of chloroform extract of Artemisia maciverae Linn

In the search for new plant-derived anti-malarial compounds, chromatographic fractions of chloroform extract of whole plants of Artemisia maciverae were tested in vivo using chloroquine resistant and chloroquine sensitive Plasmodium berghei NK 65 infected Swiss albino mice. One fraction and a sub-fraction of this were most active at 10/mg and cleared parasitemia in mice within 3 days. The different fractions and sub-fractions were tested with different reagents to determine the broad classes of compounds present. The active fraction tested positive for triterpenes and alkaloids, and the sub-fraction for only triterpenes. These tests suggest that the anti-malarial activities observed with these fractions may be due to these classes of compounds in the chloroform extract of the A. maciverae. Further chemical work is however required to characterize the active constituents.

Antitrypanosomal effects of petroleum ether, chloroform and methanol extracts of Artemisia maciverae Linn

Petroleum ether, chloroform and methanol extracts of A. maciverae were studied in vitro and in vivo for activity against Trypanosoma brucei brucei in Swiss albino mice. Thereafter, the chloroform extract which showed the highest activity in both in vitro and in vivo assessments was subjected to bioassay-guided fractionation. The crude extracts and the fractions of the chloroform extract of A. maciverae were screened for phytochemicals and secondary metabolites. Combined fractions 54-57 of this extract showed the highest in vitro antitrypanosomal activity, and at 10 mg/kg body weight, this fraction cleared the parasitemia completely from T. brucei brucei infected Swiss albino mice after 7 days of treatment. There was no statistically significant difference in the level of parasitemia when the infected mice treated with this fraction was compared with the standard trypanocidal drug, diminal. The results of the phytochemical analysis showed that the crude extracts contained secondary metabolites like flavonoids, triterpenes, terpenoids, tannins, phlobatannins and alkaloids, while the active fraction contains only triterpenes and alkaloids. It can be inferred that fraction 54-57 contains the active component responsible for the high antitrypanosomal activity of the chloroform extract of A. maciverae.

Quantitative changes in gastric mucosal glycoproteins: effect of cholinergic agonist and vagal nerve stimulation in the rat

The role of the vagus nerve and cholinergic mechanisms in the control of the rat gastric mucin and protein (PROT) release in vivo was investigated. Under urethane anaesthesia (1.25 g kg(-1)), the rats had their gastric lumen perfused with saline. Mucus secretion was measured as a function of adherent mucus on the mucosa surface and the luminal content of sialic acids (SIA), galactose (GAL), pyruvate and PROT. Electrical stimulation of the vagi significantly increased the levels of mucus (3.23 +/- 025 microg g(-1) tissue, P < 0.05), free sialic acid (FS) (0.18 +/- 0.04 mg mL(-1), P < 0.05) and PROT (0.25 +/- 0.003 mg mL(-1), P < 0.05) when compared with control animals. Bilateral cervical vagotomy had no significant effect on adherent mucus or basal levels of PROT, SIA and GAL (P > 0.05) with respect to the control. In both vagotomized and vagal intact animals, the cholinergic agonist (carbachol, 200 mg kg(-1)) significantly increased PROT, adherent mucus and FS (P < 0.05) and decreased bound sialic acid (P > 0.05). There were no visible haemorrhagic streaks on the gastric mucosa of vagotomized, vagal intact and carbachol-treated animals. The results suggest that vagus nerve does not exert a tonic control on gastric glycoprotein secretion in vivo and that cholinergic effect on the mucus secreting cells may be implemented via the intrinsic nerves of the enteric nervous system.

Effect of dibutyltin(IV) on the ultrastructure of African Trypanosoma spp

Diorganotins (R2SnX2) are compounds with a wide variety of biological properties. In an attempt to follow the morphological events and to characterize the toxic effects of diorganotins on in vitro cultured African Trypanosoma spp., the ultrastructural alterations induced on the parasites by dibutyltins (Bu2SnX2) were followed. The data obtained indicate that these compounds induced irreparable damage to the in vitro cultured bloodstream forms of the parasites. Transmission and scanning electron microscopy allowed observations on the perturbation of the kinetoplast, extensive cytoplasmic swellings, disconfiguration around the flagellar pocket and membrane disintegration. Fluorescence microscopy with 4,6-diamidine-2-phenylindole stain was also used to visualize the survival or degeneration of kDNA. Understanding the collateral cellular toxic effect of these compounds on the parasites may shed light on the possible mechanism by which they kill trypanosomes. Agarose gel electrophoresis resolution of isolated kDNAs revealed no fragmentation by these compounds following in vitro incubation at 37 degrees C. However, fragmentation was observed from the gel electrophoresis of kDNA isolated from in vitro cultured Bu2SnX2-exposed parasites. Transmission electron microscopy of the kDNAs revealed the same pattern as observed with gel electrophoresis. These results provide evidence for the possible involvement of the Bu2Sn moiety in the in vivo-induced fragmentation of trypanosomal kDNA and consequent trypanolysis. This observation also underlies the relevance of organometallics in the therapy of African trypanosomiasis.

In vitro trypanocidal activity of dibutyltin dichloride and its fatty acid derivatives

Searching for new compounds against pathogenic trypanosomes has been substantially accelerated by the development of in vitro screening assays. In an attempt to explore the chemotherapeutic potential of organotin compounds and to broaden the search for newer trypanocides, fatty acid derivatives of dibutyltin dichloride were synthesized and their in vitro trypanocidal profiles studied on Trypanosoma brucei brucei, Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense. A 24-h time course experiment was conducted with various concentrations of the compounds using a 24-well microtiter plate technique. The compounds tested were trypanocidal in a dose-dependent fashion: inhibiting survival and growth, resulting in irreversible morphological deformation and the eventual death of the parasites. The minimum inhibitory concentrations of the tested diorganotins are at low micromolar ranges: from 0.15-0.75 microM for T. b. brucei, T. b. gambiense and T. b. rhodesiense. These observations suggest that organotin has chemotherapeutic potential.

Indigenous knowledge system for treatment of trypanosomiasis in Kaduna state of Nigeria

A survey was carried out in Kaduna State of Nigeria to establish the indigenous knowledge system for treating trypanosomiasis in domestic animals. Questionnaire and interviews were, respectively, administered to, or conducted with about 200 livestock farmers and traders spread around the state. Data obtained revealed the use of several plants either alone or in combination, for the treatment and management of trypasonomiasis. The most common plants encountered were Adansonia digitata, Terminalia avicennoides, Khaya senegalensis, Cissus populnea, Tamarindus indica, Lawsonia inermis, Boswellia dalzielli, Pseudocedrela kotschi, Syzyium quinensis, Sterculia setigera, Afzelia africana, Prosopis africana, Lancea kerstingii. The method of preparation and mode of administration of some of these plants in the treatment of trypanosomiasis are reviewed and discussed.

Phospholipase A2 from Trypanosoma brucei gambiense and Trypanosoma brucei brucei: inhibition by organotins

Activity and kinetics of phospholipase A2 (PLA2) from Trypanosoma brucei gambiense (Wellcome strain) and Trypanosoma brucei brucei (GUTat 3.1) were examined using two different fluorescent substrates. The activity in the supernatants of sonicated parasites was Ca2+-independent, strongly stimulated by Triton X-100 with optimum activity at 37 degrees C and pH 6.5-8.5. To encourage a possible interaction between the parasite enzyme and organotin compounds, fatty acid derivatives of dibutyltin dichloride were synthesized and evaluated as potential inhibitors of PLA2. The enzyme from the two-trypanosome species differ with respect to kinetic parameters and are noncompetitively inhibited by the organotin compounds. The Michaelis constant (KM) for PLA2 from T. b. brucei is 63.87 and 30.90 microM while for T. b. gambiense it is 119.64 and 32.91 microM for the substrates 1,2-bis-(1-pyrenebutanoyl)-sn-glycero-3-phosphocholine (PBGPC) and 2-(12-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)dodecanoyl-1-hexadecanoyl-sn-glycero-3-phosphocholine (NBDC12-HPC), respectively.

Trypanocidal activity of organotin chlorides on Trypanosoma brucei-infected mice

The organotin compounds dibutyltin (DBTC) and diphenyltin dichlorides (DPTC) were tested for trypanocidal activity on a Trypanosoma brucei-infected mice model. At a dose of 10 mg DBTC and 15 mg DPTC/kg/day for five consecutive days, they cleared the parasites from the peripheral blood of the infected mice. Subinoculation of some healthy mice with the homogenates of liver, spleen, kidney, cerebrospinal fluid and blood from the mice considered cured, showed a few cases of relapse. The LD50 of DBTC and DPTC are 90 mg/kg and 75 mg/kg respectively.

Antihypertensive effect of roselle (Hibiscus sabdariffa) calyx infusion in spontaneously hypertensive rats and a comparison of its toxicity with that in Wistar rats

The LD(50) of roselle calyx extract and its effect on blood pressure were determined. The LD(50) was found to be above 5000 mg kg(-1). Roselle calyx infusion was found to lower significantly (p<0.05) both systolic and diastolic pressure in spontaneously hypertensive and normotensive Wistar-Kyoto rats at tested doses of 500 and 1000 mg kg(-1) body weight. The reduction in blood pressure in both groups was positively correlated with weight. Continuous consumption of the infusion at 1000 mg kg(-1) was discovered to lead to sudden death in spontaneously hypertensive rats but not in Wistar-Kyoto rats. Water intake was not significantly different (p>0.05) in the control groups of the two strains of rats used, neither was there a significant difference in their urine output. The water intake in the treated spontaneously hypertensive and normotensive rats was not different from the corresponding control groups. However the urine output of the treated spontaneously hypertensive rats was significantly higher. A significant decrease in serum creatinine, cholesterol, and glucose in the treated rats compared with the control as well as a significant increase in serum uric acid was observed. The serum proteins (albumin and total protein) in the treated rats when compared with the control groups was not changed significantly.

Normal plasma lactose concentrations and kinetics of intravenously infused lactose in cattle

Plasma lactose concentration and its kinetics were determined in apparently normal cattle, as a prelude to investigating its chemotherapeutic significance in bovine trypanosomiasis. It is hoped that intravenously administered lactose may be able to reduce the rate of sequestration of desialylated erythrocytes during Trypanosoma vivax infection of cattle; thus decreasing the rate of development of trypanosomal anaemia in infected animals. A range of 0.061 to 0.55 mM with a mean of 0.208 +/- 0.128 mM standard deviation (SD), observed in adult cattle was significantly lower (P<0.001) than corresponding values in recently weaned calves; 0.429 to 1.496 mM (0.972 +/- 0.318 mM). Semi-logarithmic plots from calves given a single dose (0.5 g lactose per kg bodyweight as a solution in normal saline, infused at the rate of 18 ml min(-1)) showed a biexponential pattern of regression lines. Decrease in plasma concentrations was biphasic and lactose was rapidly distributed into the extravascular space after administration. The biological half-life (t1/2) of the infused lactose ranged from 4.10 to 6.00 hours (5.01 +/- 0.81 hours); its mean elimination rate constant was 0.14 +/- 0.02 hour(-1), mean apparent volume of distribution was 168.09 +/- 56.65 ml kg(-1) while its mean total clearance was 23.54 +/- 8.31 ml kg(-1) hour(-1). A single dose rapidly reached a peak and gradually fell below the pre-infusion level while repeated doses did not cause accumulation of the lactose in the plasma as each infusion fell back to normal relatively rapidly.

Effects of acute bovine trypanosomosis (Trypanosoma vivax) on plasma kinetics of intravenously administered lactose

Four calves infected with Trypanosoma vivax and four uninfected control calves were each injected intravenously with repeated doses of 0.5 g lactose kg-1 body weight, thrice daily at intervals of 4 h. Plasma samples were collected at specified time intervals and analysed for lactose. Pharmacokinetic parameters were calculated from the data. T. vivax infection delayed excretion of lactose from the body, thus leading to significantly (P < 0.001) increased biological half life (t1/2) and a significantly (P < 0.001) reduced elimination rate constant for lactose in the body. The apparent volume of distribution and total clearance of lactose were not affected by the infection. T. vivax infection also appeared to cause accumulation of lactose in the plasma after repeated intravenous administration.