Prevalence and geographical distribution of Papio hamadryas papillomavirus 1 (PhPV1) in Kenyan baboons.

Papio hamadryas papillomavirus (PhPV) 1, 2, and 3, are Alphapapillomaviruses that have been detected in Kenyan Olive baboons but the distribution is unknown. Therefore, cervical screening for PhPV1 was performed in baboons from various areas in Kenya using a nested polymerase chain reaction. The prevalence rate was 33%.

In Vitro and In Vivo Toxicological Evaluation of Avicennia africana P: Beauv. (Avicenniaceae) Leaf Extract in a Rat Model.

Avicennia africana is an important ethnomedicinal plant that has long been used to treat malaria and several other diseases. Despite the plant's antimalarial and other therapeutic properties, there is limited evidence-based data on its potential toxicity. Hence, the purpose of the current study was to assess the safety of A. africana leaf ethanolic extract (AAE). The study was designed to ascertain the cytotoxic effects of the crude extract on red blood cells (RBCs) as well as the acute and subacute toxicity in Wistar albino rats in accordance with Organization for Economic Co-operation and Development (OECD) guidelines "Test No. 423" and CPMW/SWP/1042/99. The pulverized, shade-dried plant leaves were sequentially macerated with 70% ethanol to obtain the crude extract (AAE). The extract's cytotoxic activity (CC50) against the uninfected human red blood cells (RBCs) was determined using the 3-(4,5-Dimethylythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. For the acute toxicity studies, the rats (male and female) were divided randomly into six groups of five rats (n = 5) and dosed orally once with the following dose levels: 100, 300, 1000, 3000, and 5000 mgkg-1, p.o. of the extracted AAE, with the control group receiving only the vehicle. In the repeated dose toxicity studies, the rats (both sexes) were orally administered daily with AAE at 100, 300, and 1000 mgkg-1 for 14 days. Rat body weights were measured, and blood samples were tested for haematological and biochemical markers. Internal organs like the heart, kidney, liver, and spleen were collected, inspected, and weighed, and histological examinations were performed. The median lethal dose (LD50) value is greater than 5000 mgkg-1 body weight, with no significant change in bodyweight or relative organ weight (ROWs) of the extract-treated groups or control group. The extract showed greater cytotoxicity activity (CC50), which was >100 µg/mL, compared to the reference drug (artesunate).The dosage groups of 100 and 300 mgkg-1bwt had neutrophilia and lymphocytopenia (p < 0.05). However, changes in these haematological parameters may not be dose dependent and could be stress related. All the serum biochemical markers studied in rats given AAE did not show any significant change (p > 0.05). Histopathological examination of internal organs of AAE-treated rats did not show any significant abnormalities resulting from the extract treatment compared to the control group. Based on the findings in the present study, the LD50 value of AAE was found to exceed 5000 mgkg-1 in the acute toxicity test, while the no observed adverse effect level (NOAEL) in rats was 1000 mgkg-1 p.o. In the sub-acute toxicity tests. Histopathological analysis revealed no morphological abnormalities in the vital organs.

Gross and Histopathology of Goats Feeding on Opuntia stricta in Laikipia County, Kenya.

Various plant species such as Opuntia stricta have developed defensive measures, namely, spines, thorns, and other sharp pointed structures to protect themselves from herbivores and other animals feeding on them. Opuntia stricta has invaded the northern part of Laikipia County, Kenya, and its fruits are protected by small spines called glochids. This study determined the pathology in goats feeding on this plant in Laikipia County. Eighteen goats that had eaten the plant and six others that were raised in a ranch without O. stricta were purchased for the study. All study animals were clinically examined for lesions and euthanized for necropsy examination. Clinically, goats affected by O. stricta had poor body condition, wounds on various body parts, and diarrhea. Variable numbers of O. stricta spines occurred externally on the skin throughout the body and elicited pain, swelling, and ulcerative wounds on affected parts. Internal lesions were observed in subcutaneous tissues (100%), together with stomatitis, cheilitis, gingivitis, glossitis, abomasitis (100%), rumen, reticulum, omasum thinning and loss of papillae (72.2%), esophagitis, and duodenitis (5.6%). Carcasses had gelatinous fat and muscular atrophy. Other gross lesions were generalized viscera atrophy, edema, subcutaneous emphysema, lymphadenopathy, abscesses, ascites, hydrothorax, and hydropericardium. The abomasum wall and its mucosal folds were swollen with edema, haemorrhages, and scattered foci of abscesses. Histopathology confirmed the main lesions in all affected goats were foreign-body granulomas which were located in all organs with gross lesions. Goats from O. stricta-free ranches had no spines or lesions. The pathological effects caused by O. stricta resulted in emaciated goats due to pain, inability to masticate and assimilate food, and stress, resulting in poor carcass and organs quality and possible condemnation and death. This could affect the socioeconomics and livelihoods of communities in the study area, and therefore, the spread of this plant needs to be controlled.

Antidepressant and Anxiolytic Effects and Subacute Toxicity of the Aerial Parts of Psychotria ankasensis J.B.Hall (Rubiaceae) in Murine Models.

BACKGROUND: The present study aimed at validating the traditional use and toxicity profile of a methanolic extract of the aerial parts of Psychotria ankasensis in alleviating depression and anxiety disorders. METHOD: The antidepressant effect of methanolic extract of Psychotria ankasensis (PAE 30, 100, and 300 mg/kg, p.o.) was assessed in mice using the forced swim test (FST) and the tail suspension test (TST). The plant's anxiolytic potential was also evaluated in mice using the elevated plus-maze (EPM) and the open field tests (OFT). The subacute toxicity was assessed via oral administration of PAE at doses of 100, 300, and 1000 mg/kg in rats for 28 days. RESULTS: PAE 100 and 300 mg/kg showed antidepressant-like properties by significantly (at least p < 0.05) decreasing the frequency and duration of immobility in FST and TST. PAE (100 and 300 mg/kg) also showed a significant (at least p < 0.05) anxiolytic effect in both EPM and OFT. In the EPM test, E max for PAE and diazepam were 92.52 ± 40.11% and 85.95 ± 45.92%, respectively, whereas E max was approximately 100% for both test drugs in the OFT. Subacute administration of PAE did not reveal any toxic effects with respect to organ weight index, haematological, serum biochemical, and histopathological parameters. CONCLUSIONS: Methanolic extract of P. ankasensis exhibited antidepressant-like and anxiolytic-like effects devoid of significant toxicity at the doses tested in murine models.

Efficacy of Ivermectin, Liquid Paraffin, and Carbaryl against Mange of Farmed Rabbits in Central Kenya.

Mange is a common disease of rabbits globally, and knowledge of efficacy of drugs used in its treatment is critical for effective disease control. The current study evaluated the efficacy of three commonly used therapeutic agents in Kenya against mange. In a controlled laboratory trial, 20 adult rabbits were recruited for the study (16 of which were infested with mange, while 4 were mange-free). The 16 mange-infested rabbits were randomly allocated into 4 treatment groups each consisting of 4 rabbits, while 4 mange-free rabbits formed the negative control group. Treatments were administered as follows: group 1 (G1) received two ivermectin injections at an interval of 14 days, group 2 (G2) was treated with a combination of carbaryl and liquid paraffin applied every other day up to the end of the experiment, group 3 (G3) was treated with liquid paraffin droplets applied daily until the lesion cleared, while group 4 (G4, infected-untreated) received distilled water applied topically on their ears and group 5 (G5, uninfected-untreated negative control) was not treated with any preparation. The lesions were scored and sampled daily to check the viability of the mites. A field efficacy trial of the test compounds was performed using 105 mange-infested rabbits. The results revealed that all the test agents: ivermectin, liquid paraffin, carbaryl-water, and carbaryl-liquid paraffin combination were effective against mange, recording the lesion score of zero for psoroptic mange by day 21 in the laboratory and field trials. Lesion scores in the treated groups were significantly reduced (p < 0.05) at the termination of study compared with those of the positive control group in the laboratory trial. A point-biserial correlation revealed a strong association (r pb = 0.79, p < 0.05) between the presence of viable mites and degree of psoroptic lesions in the field trial.

Hematologic Values of Healthy and Sick Free-ranging Lesser Flamingos ( Phoeniconaias minor) in Kenya.

We determined hematologic parameters of five healthy and nine sick free-ranging Lesser Flamingos ( Phoeniconaias minor) from Lake Nakuru, Kenya. Heterophilia and lymphopenia were evident in sick birds, with up to 7.5-fold higher heterophil-to-lymphocyte ratio in sick birds compared to healthy birds. Leucopenia was present in a few sick birds. A higher than normal packed cell volume was observed in birds that had evidence of acute disease, whereas a lower than normal packed cell volume was seen in birds with evidence of prolonged sickness. Healthy birds had higher total white blood cell counts and lymphocyte counts and lower heterophil counts than zoo flamingos. Most sick birds were diagnosed with septicemia, occasionally with fibrinous exudation into the coelomic cavities. One bird had mycobacterial granulomas, one had a corynebacterium-associated wing abscess, and one had a wing fracture. We provide hematologic data for free-ranging Lesser Flamingos and compare the parameters of sick and healthy birds.

Efficacy of Sulphachloropyrazine, Amprolium Hydrochloride, Trimethoprim-Sulphamethoxazole, and Diclazuril against Experimental and Natural Rabbit Coccidiosis.

There are no anticoccidial drugs labelled for rabbits in Kenya and those available are used as extra labels from poultry. The drugs are used in rabbits with limited knowledge of their efficacy and safety. The aim of this study was to determine the efficacy of sulphachloropyrazine, amprolium hydrochloride, and trimethoprim-sulphamethoxazole relative to diclazuril when used curatively against experimental and natural rabbit coccidiosis. In a controlled laboratory trial, sixty (60) rabbits were randomly allocated to six treatment groups, namely, 1A, 2B, 3C, 4D, 5E, and 6F, each with 10 rabbits. Groups 2B, 3C, 4D, 5E, and 6F were experimentally infected with mixed Eimeria species while group 1A served as uninfected-untreated (negative) control group. Four of the infected groups were treated with sulphachloropyrazine (5E), amprolium hydrochloride (2B), trimethoprim-sulphamethoxazole (6F), and diclazuril (4D) using dosages recommended by manufacturers. Group 3C served as infected-untreated (positive) control. A field efficacy trial in naturally infected rabbits was then undertaken. The results revealed that sulphachloropyrazine and diclazuril were effective against rabbit clinical coccidiosis by significantly reducing oocyst counts from 149.00±110.39 x 104 to 3.31±0.86 x 104 Eimeria spp. oocysts per gram of feces (opg) and 59.70±12.35 x 104 to 0.0±0.0 x 104 opg, respectively, in the laboratory trial. Similarly, sulphachloropyrazine and diclazuril recorded reduced oocyst counts in the field trial from 280.33±44.67 x 103 to 0.44±0.14 x 103 opg and 473.44±176.01 x 103 to 0.0±0.0 x 103 opg, respectively. Still, sulphachloropyrazine and diclazuril showed superior efficacy by registering lesion scores and fecal scores close to those of uninfected untreated control group. Trimethoprim-sulphamethoxazole recorded a satisfactory efficacy in the field trial by recording reduced oocyst counts from 266.78±37.03 x 103 to 0.75±0.11 x 103 opg but was not efficacious in the laboratory trial. Amprolium hydrochloride was not efficacious against clinical coccidiosis in both the experimental and field trials.

Cytotoxic activity of medicinal plants of the Kakamega County (Kenya) against drug-sensitive and multidrug-resistant cancer cells.

ETHNOPHARMACOLOGICAL RELEVANCE: The geographical location of Kakamega County proximal to the Kakamega Rain Forest in Kenya and its rich flora represents an interesting resource of traditional medicinal plants. The medicinal plants in the present study are traditionally used to treat cancer in Kakamega County as recorded in published literature. AIM OF THE STUDY: Due to multidrug resistance (MDR) and severe side effects of currently used drugs in clinical oncology, new candidate compounds are urgently required to improve treatment outcome. The present study explored the in vitro cytotoxic potential of 34 organic and 19 aqueous extracts of Kakamega medicinal plants towards sensitive and multidrug-resistant cancer cell lines. METHODS AND RESULTS: The cytotoxicity was determined using the resazurin assay. Eight organic and two aqueous plant extracts inhibited the growth of CCRF-CEM leukemia cells by more than 50%. The organic extracts were Harungana madagascariensis Lam. ex poir (6.6% of untreated control), Prunus africana (Hook.f.) Kalkman (19.4%), Entada abyssinica Steud. ex A. Rich (38.6%), Phyllanthus fischeri Pax (40.7%), Shirakiopsis elliptica (Hochst.) Esser Synonym: Sapium ellipticum (Hochst. kraus) Pax (41.8%), Bridelia micrantha (Hochst.) Baill (45.4%) and Futumia africana Benth. (45.8%) and Microglossa pyrifolia (Lam.) Kuntze (48%). The aqueous extracts were Bridelia micrantha (Hochst.) Baill (31.3%) and Shirakiopsis elliptica (Hochst.) Esser Synonym: Sapium ellipticum (Hochst. Kraus) Pax (48.2%). In addition to P-glycoprotein-expressing tumor cells, we also investigated other mechanisms of drug resistance, i.e. BCRP- or EGFR-transfected and TP53-knockout tumor cells. Some extracts also showed considerable cytotoxic activity against these drug-resistant cell lines. As demonstrated for selected examples, some extracts exhibited enhanced cytotoxicity towards cancer cells, if applied in combination with other extracts. DISCUSSION: The panel of medicinal plants used in the Kakamega County for cancer treatment revealed indeed cytotoxicity to various extent towards cancer cells in vitro. Hence, our results may at least in part substantiate the traditional use of these compounds to treat cancer. Even more interesting, several extracts inhibited otherwise drug-resistant tumor cell lines with similar or even better efficacy than their drug-sensitive counterparts. This provides an attractive perspective for further exploration of their anticancer potential to combat drug resistance of refractory tumors.

A 56-Day Oral Toxicity Study of the Aqueous Extract of Rapanea melanophloeos (L.) Mez in Rats.

Rapanea melanophloeos is a tropical tree that is extensively utilized in African traditional medicine to treat helminthiases, tuberculosis, and heart-water. As with many other medicinal plants, there is insufficient information regarding the safety of therapeutic R. melanophloeos extracts. An aqueous extract of R. melanophloeos stem bark was administered to Sprague Dawley rats at doses of 100 mg/kg, 300 mg/kg, and 1000 mg/kg for 56 days to characterize its potential toxicity after prolonged dosing. Blood samples were obtained fortnightly for serum chemistry and hematology, while organs were collected at the end of the study. The extract caused an increase in organ weight indices of the kidneys and testis at 300 mg/kg and 1000 mg/kg. Hematological and biochemical examination revealed a drop in leukocyte counts and the hematocrit at 1000 mg/kg dose level, while there was a general but nondose-related elevation in alkaline phosphatase activity. There were time-associated variations in the hematological and clinical chemistry parameters at days 28, 42, and 56 in all dose levels, but most values remained within physiological limits. No pathological lesions were evident at histopathology after treatment with the extract. Our data shows that the aqueous extract of R. melanophloeos is not likely to be toxic at the doses tested and provides support to its medicinal use.

Sub-acute toxicity of the chloroformic extract of Rapanea melanophloeos (L.) Mez in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Cape beech (Rapanea melanophloeos) is an important medicinal plant that is widely used in most of Africa. Currently, little toxicological information is available on its safety following prolonged use. AIM OF THE STUDY: In this study, we sought to evaluate the oral sub-acute toxicity of Rapanea melanophloeos stem bark chloroformic extract using Sprague Dawley rats. MATERIALS AND METHODS: Six-week old rats were orally administered with the extract at dosage levels of 100 mg/kg, 300 mg/kg and 1000 mg/kg for 28 days. Clinical signs, hematological and clinical chemistry parameters were monitored, while organ weights and organ pathology were evaluated at the end of the study. RESULTS: The extract caused a significant reduction in bodyweight at 1000 mg/kg. The hematological profiles of animals at this dose showed an increase in the erythrocyte count and the hematocrit that were accompanied by decrease in the mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration. Biochemical parameters were not altered in a dose-related manner when compared to the controls. There were time associated alterations on both hematological and biochemical parameters, but pathological examination did not reveal any treatment related changes in any of the organs. CONCLUSION: Our results demonstrate that the chloroformic stem bark extract of Rapanea melanophloeos may be of no toxicological concern at dosage levels up to 1000mg/kg. Rapanea melanophloeos can therefore be used confidently in African traditional medicine at these or lower dosage levels.

Medicinal plants used in treatment and management of cancer in Kakamega County, Kenya.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional medicine plays a critical role in treatment of chronic debilitating and life threatening conditions and diseases. Cancer is one such condition whose therapeutic intervention is commonly through inexpensive traditional herbal remedies. Increasingly industrialised societies are developing drugs and chemotherapeutics from these traditional herbal plants. Plant biogeography determines the abundance and availability of medicinal plants which in turn determine their use by local communities. The present study was carried out in Kakamega County of Kenya to identify and document medicinal plants used for treatment and management of cancer states by communities living adjacent to Kakamega Tropical rainforest of Kakamega County, Kenya. MATERIALS AND METHODS: An ethnobotanical survey was done using semi-structured questionnaires administered to 32 randomly selected herbalists from Kakamega County. RESULTS AND DISCUSSION: Sixty five (65) plants of 59 genera and 32 families were identified as candidates in therapeutic intervention against cancer states. Most commonly cited plant species were Spathodea campanulata P. Beauv. ssp. nilotica (Seem), Microglossa pyrifolia (Lam.) Kuntze, Harungana madagascariensis Lam. ex poir, Prunus africana (Hook. f.) kalkman, Cyphostemma serpens (A. Rich), Catharanthus roseus (L.) G. Don and Aloe volkensii Engl. The following were documented for the first time; Aeschynomene abyssinica (A. Rich.) Vatke, Synsepalum cerasiferum (welw.) T. D penn., Albizia coriaria Welw. ex Oliv., Aloe volkensii Engl. Bridelia micrantha (Hochst.) Baill, Croton macrostachyus Delile, Cyphostemma serpens (A. Rich), Dicliptera laxata C.B. Clarke, Ekebergia capensis Sparrm., Gardenia volkensii K. schum. ssp. volkensii, Glycine wightii (wight & Arn.), Ocimum gratissimum Suave, Olea hotcsh spp. hochstetteri, Pavetta abyssinica Fresen., Phyllanthus fischeri Pax, Psydrax schimperiana (A. Rich), Rhus vulgaris Meikle, Senna didymobotyra (Fresen.) Irwin and Barneby, Solanecio nandensis (S. Moore) C. Jeffrey, Solanum mauritianum Scop, Spathodea campanulata P. Beauv. ssp. nilotica (Seem), Spermacoce princea (K. Schum.) Verdc., Tabernaemontana stapfiana Britten, Tragia brevipes Pax and Zanthoxylum gilletii (De Wild.) P.G.Waterman. The most frequently used plant parts were fresh or dried leaves and stem barks. Administration to patients was almost exclusively oral, with the exceptions being topical application especially for breast cancer and skin sarcomas. CONCLUSIONS: This study identified diverse medicinal plants used in therapeutic and management intervention against cancer by communities living adjacent to Kakamega Tropical Rainforest. The primary mode of administration was oral.

Ethnodiagnostic skills of the digo community for malaria: a lead to traditional bioprospecting.

Malaria is a major public health problem that is presently complicated by the development of resistance by Plasmodium falciparum to the mainstay drugs. Thus, new drugs with unique structures and mechanism of action are required to treat drug-resistant strains of malaria. Historically, compounds containing a novel structure from natural origin represent a major source for the discovery and development of new drugs for several diseases. This paper presents ethnophytotherapeutic remedies, ethnodiagnostic skills, and related traditional knowledge utilized by the Digo community of the Kenyan Coast to diagnose malaria as a lead to traditional bioprospecting. The current study was carried out in three Digo villages of Diani sub-location between May 2009 and December 2009. Data was collected using semi-structured interviews, and open and close-ended questionnaires. A total of 60 respondents (34 men and 26 women) provided the targeted information. The results show that the indigenous knowledge of Digo community on malaria encompasses not only the symptoms of malaria but also the factors that are responsible for causing malaria, attributes favoring the breeding of mosquitoes and practices employed to guard against mosquito bites or to protect households against malaria. This knowledge is closely in harmony with scientific approaches to the treatment and control of the disease. The Digo community uses 60 medicinal plants distributed in 52 genera and 27 families to treat malaria. The most frequently mentioned symptoms were fever, joint pains, and vomiting while the most frequently mentioned practices employed to guard against mosquito bites and/or to protect households against malaria was burning of herbal plants such as Ocimum suave and ingestion of herbal decoctions and concoctions. The Digo community has abundant ethnodiagnostic skills for malaria which forms the basis of their traditional bioprospecting techniques.