Acute Toxicological, Analgesic and Anti-Inflammatory Effects of Methanol Extract of Laggera aurita Linn F (Compositae) in Mice and Rats

Background: The plant Laggera aurita is an annual or biannual plant belonging to the family Compositae that has been used for management of pain related conditions locally.  It reportedly has anti-oxidant as well as antimicrobial properties. Objectives: To conduct LD50 and phytochemical studies, evaluate the analgesic and anti-inflammatory properties of the methanol extract of L. aurita and determine possible mechanism of action. Methodology: Analgesic and anti-inflammatory properties of the extract were investigated using acetic acid induced writhing, thermally-induced pain, and formalin induced inflammation in rats and mice. Phytochemical and acute toxicological screenings were also conducted. Results: The LD50 was found to be above 5000 mg/kg with slight changes in histological architecture observed in the kidney, liver, lungs and stomach. The extract at dose 200, 400 and 800 mg/kg significantly (p<0.05) inhibited acetic acid induced writhes in mice and increased mean reaction time in the thermal pain model, both dose dependently. The effect on thermally induced pain was blocked by naloxone, a non-specific opioid antagonist, suggesting opioid receptor involvement in analgesia. The extract also significantly (p<0.05) decreased formalin induced paw edema dose dependently. Conclusion: These findings suggest that the methanol extract of L. aurita possesses analgesic and anti-inflammatory properties that justify its ethnomedicinal use in management of pain and inflammation. Keywords: Laggera aurita, anti-inflammatory, analgesic, acute toxicity

Anticonvulsant activity of methanol stem bark extract of Boswellia dalzielii Hutch. (Burseraceae) in mice and chicks

Background: Boswellia dalzielii is a widely used medicinal plant in African traditional medicine. The efficacy of its stem bark extract in management of convulsions is well acclaimed among communities of Northern Nigeria. Objective: To evaluate the anticonvulsant potentials of methanol stem bark extract of Boswellia dalzielii in mice and chicks. Methodology: Phytochemical screening, elemental analysis and acute toxicity studies was carried out. The extract was evaluated for anticonvulsant activity against electrically-induced seizures in chicks and against pentylenetetrazole, strychnine, picrotoxin and 4-aminopyridine-induced seizures in mice at doses of 20, 40 and 80 mg/kg. Results: The intraperitoneal LD50 was estimated to be 280 and 570 mg/kg in mice and chicks respectively. The extract at 20 mg/kg provided 40% protection and significantly (p<0.05) increased the mean onset of seizure in MEST. A dose-dependent and significant (p<0.05) increase in the mean onsets of pentylenetetrazole and strychnine-induced seizures were produced by the extract at 80 mg/kg. Similarly, a dose-dependent and significant increase (p<0.05 and p<0.01) in latency to picrotoxin-induced convulsions was observed at 40 and 80 mg/kg respectively. Conclusion: These findings suggests the methanol stem bark extract of Boswellia dalzielii possesses anticonvulsant activities and thus supports the ethnomedical rationale for its use against convulsions. Keywords: Anticonvulsant, Boswellia dalzielii, Epilepsy, Pentylenetetrazole, Picrotoxi

Renal impact of sub acute lamivudine-artesunate treatment in wistar rats

Background and objectives: Lamivudine and artesunate are life saving drugs in the treatment of HIV/HBV and malaria respectively, and available data shows artesunate having anti-tumour properties. The concurrent administration of both drugs presents important safety concerns. This study investigated possible effects of lamivudine-artesunate co-administration on renal function and histology in wistar rats. Method: Four groups of rats (n=5) were used in the study with one group as control. Two groups received lamivudine at 20 mgkg-1, with another receiving artesunate at 10 mgkg-1. Artesunate was added to one of the lamivudine groups. While lamivudine treatment was for three weeks, artesunate was introduced only in the last week of the study alone, or in combination with lamivudine. At termination, animals were humanely killed and kidneys harvested, weighed and subjected to H and E stain and observation. Serum urea and electrolytes were also determined. Results: Serum biomarkers and kidney weights did not differ significantly (p>0.05). Various histological changes were observed in the treated groups although these didn’t directly correlate the biomarkers determined. Conclusion: The concurrent use of lamivudine and artesunate appears to be safe within the dose levels used. However caution may be needful when repeated or long term exposure is required. Keywords: artesunate, lamivudine, HIV, HBV, malaria, concurrent drug therap