Acute toxicity studies of Catharanthus roseus aqueous extract in male Wistar rats

Background: The knowledge of the healing virtues of Catharanthus roseus and a host of other medicinal plants has been in existence since ancient times. Catharanthus roseus is traditionally used more commonly as anti-diabetic and anti-malaria remedy. Lack of adequate pharmacological and toxicological data of natural products to support their use is a major setback. Objective: To establish the acute toxicity effect of Catharanthus roseus crude aqueous extract on some hematological and biochemical parameters. Methodology: Catharanthus roseus aqueous extract was orally administered once to two groups of male rats at 1000 and 5000 mg/kg body weight respectively alongside a control group which received 2ml distilled water. Hematological and biochemical assays were done at 48 hours and the 14th day. The data was analyzed using SPSS 17.0. Results: White blood cells (WBC), creatinine, urea, alanine aminotransferase and aspartate aminotransferase showed significant increase while mean cell volume reduced significantly at 48 hours in the high dose group. The body weight change was also significantly reduced. Discussion: The alterations of the body weight gain, various biochemical and hematological parameters reflect the effect of toxicity after exposure of the tested extract doses. Total proteins concentration was not altered suggesting that the renal and liver functions were not adversely affected. Key words: Catharanthus roseus, acute toxicity, rat

Influence of Aspilia pluriseta Schweinf (Asteraceae) on the healing of dermal excision wounds (mouse model) and skin sensitization activity (Guinea pig model)

Background: The skin is highly predisposed to injury because of its direct contact with the environment. The aim of treating of wounds is to both hasten healing, and to minimise the occurrence of perturbations of the healing process. Many plants traditionally used to treat wounds have been proven to support the healing process using scientific models. Aspilia pluriseta has been used by a number of communities in East and Southern Africa to treat wounds. Objectives: This study aimed at testing ethnomedical claims of wound healing activity of A. pluriseta using preclinical models. Methods: Aerial parts of the plant were ground and incorporated into an ointment base (10% and 20% w/w) to evaluate the influence of the plant on the healing of acute excision wounds in mice compared to Silverex Cream® and Simple Ointment (B.P.). The 20% ointment was tested for skin sensitization in guinea pigs. Results: The effects of the plant-based ointments on wound contraction and gross epithelialisation time were less than significantly different from the controls (p≥0.05), but histopathologic examination revealed remarkable epithelialisation and collagen deposition in the wounds treated with the these ointments. The 20% A. pluriseta-based ointment induced moderate allergic contact dermatitis. Key words: Aspilia pluriseta, wound healing, skin sensitization, excision wound mode

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

Acute toxicity of the aqueous-methanolic Moringa oleifera (Lam) leaf extract on female Wistar albino rats

Background: Herbal preparations are widely assumed to be safe on oral administration and therefore the documentation of the toxic potential of some herbal concoctions used as medicine and nutrients is limited. Moringa oleifera (MO) is a plant that is gaining tremendous popularity in rural communities in Kenya as a means of offsetting nutritional and medicinal needs. However, very little is known about the safety of the plant on oral administration. Thus, the aim of the current study was to assess the biochemical and histological changes in the liver following the administration of an aqueous-methanolic (AQ-ME) MO leaf extract in female Wistar albino rats.Methods: Acute oral toxicity study on the AQ-ME MO leaf extract was conducted by the use of the limit test dose of the up and down procedure (OECD guideline number 425) with slight modifications. Briefly, ten (10) healthy, nulliparous, non-pregnant female Wistar strain albino rats aged               8-12 weeks and weighing 180±20 grams were used for the study. These animals were randomly selected into two groups; control and treatment group each having five (5) animals. They were then labelled to enable identification and control group animals were orally administered with physiological buffer saline once daily over a 48-hour period. The five (5) rats in the treatment group were dosed orally one at a time and once daily with a 2000 mg/kg dose of the AQ-ME MO leaf extract to determine the median lethal dose over a 48 hour period. Blood was then collected and used to prepare serum for biochemical analysis of aspartate amino transferase (AST), alanine amino transferase (ALT) and total bilirubin (TB) which are important biomarkers of liver dysfunction. Biochemical assays of these enzymes were performed using the method of the International Federation of Clinical Chemists (IFCC). Death was used as an endpoint, livers harvested and used to prepare transverse sections for histopathological examination. These sections were stained using the haematoxylin and eosin (H&E) method and observed for pathological changes using an optical microscope.Results: A 2000 mg/kg oral dose of AQ-ME MO leaf extract caused a significant (p0.05) increase in the mean levels of total bilirubin in the treatment group relative to the control group. On the other hand, the extract caused a non-significant (p>0.05) decrease in the mean levels of ALT in the treatment group relative to the control. The post mortem analysis of the hepatic index (liver to body weight ratio) revealed that there was a non-significant increase (p>0.05) in the hepatic index of the treatment group relative to the control. However, the transverse liver sections of treatment group animals showed mild distortions in the architecture of liver cells.Conclusions: Based on these results, the LD50 of the AQ-ME MO leaf extract was found to be >2000 mg/kg in female wistar albino rats

Ethnopharmacological survey of Samburu district, Kenya

<p>Abstract</p> <p>Background</p> <p>Ethnobotanical pharmacopoeia is confidently used in disease intervention and there is need for documentation and preservation of traditional medical knowledge to bolster the discovery of novel drugs. The objective of the present study was to document the indigenous medicinal plant utilization, management and their extinction threats in Samburu District, Kenya.</p> <p>Methods</p> <p>Field research was conducted in six divisions of Samburu District in Kenya. We randomly sampled 100 consented interviewees stratified by age, gender, occupation and level of education. We collected plant use data through semi-structured questionnaires; transect walks, oral interviews and focus groups discussions. Voucher specimens of all cited botanic species were collected and deposited at University of Nairobi's botany herbarium.</p> <p>Results</p> <p>Data on plant use from the informants yielded 990 citations on 56 medicinal plant species, which are used to treat 54 different animal and human diseases including; malaria, digestive disorders, respiratory syndromes and ectoparasites.</p> <p>Conclusion</p> <p>The ethnomedicinal use of plant species was documented in the study area for treatment of both human and veterinary diseases. The local population has high ethnobotanical knowledge and has adopted sound management conservation practices. The major threatening factors reported were anthropogenic and natural. Ethnomedical documentation and sustainable plant utilization can support drug discovery efforts in developing countries.</p

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

Antibacterial and cytotoxic activity of Kenyan medicinal plants

Seven medicinal plant extracts traditionally used in Kenya, mainly for management of infectious conditions, were chosen and screened for their antibacterial activity against Gram-negative ( Pseudomonas aeruginosa and Escherichia coli ) and Gram-positive ( Bacillus cereus and Staphylococcus aureus ) bacteria. Antibacterial activity was tested using the broth dilution method. Harrisonia abyssinica and Terminalia kilimandscharica extracts showed significant activity against Gram+ and Gram- bacteria. The methanolic extracts of T. kilimandscharica bark and H. abyssinica bark and leaves showed minimum inhibitory activity against all tested bacteria, with minimal inhibitory concentrations ranging from 25-150 mg/mL. Ajuga remota and Amaranthus hybridus , which are lethal to brine shrimp nauplii, showed significantly lower antibacterial activity than those that were relatively non-toxic

Lewaso Aplea (66 years), The most revered and knowledgeable of the remaining traditional healers in Samburu District displaying, Sond

() and L.() during the field collection.<p><b>Copyright information:</b></p><p>Taken from "Ethnopharmacological survey of Samburu district, Kenya"</p><p>http://www.ethnobiomed.com/content/4/1/14</p><p>Journal of Ethnobiology and Ethnomedicine 2008;4():14-14.</p><p>Published online 23 May 2008</p><p>PMCID:PMC2412850.</p><p></p