Seasonal variation in uterotonic activity of Rhoicissus tridentata extracts

Background. Rhoicissus tridentata lignotubers are widely used in southern African traditional pregnancy-related remedies.Objectives. To determine the seasonal variation in contractile activity of extracts from different parts of the plant.Methods. Isolated rat uterus tissue was used to compare the contractile activity of crude aqueous extracts of R. tridentata made from plant material harvested every 3 months over a period of 2 years.Results and conclusions. The activity of the plant extracts from plants harvested in summer and autumn were 4 - 5- fold higher than extracts from plants harvested in winter or spring. The tubers stimulated the greatest degree of contractions, followed by the stems, roots and leaves. These results highlight the need to standardise the timing of harvesting R. tridentata

Toxicovigilance I: A survey of acute poisonings in South Africa based on Tygerberg Poison Information Centre data

Background. The incidence and spectrum of acute poisonings in South Africa are unknown. Poisoning data can be derived from sourcessuch as hospital admission records and poison information centre (PIC) records.Objectives. This study was conducted to examine the extent of the problem and to identify trends and toxicovigilance issues using PIC data.Methods. A survey was conducted based on Tygerberg Poison Information Centre (TPIC) consultations over 1 year. TPIC consultationforms were analysed for patient demographics and causes of poisoning.Results. The TPIC dealt with 4 771 consultations related to human exposures to poisonous substances. The study showed that accidentalexposure was more common than intentional poisoning (65.2% v. 34.8%); that 55.8% of cases were adults, of which 57.6% were females;and that 61.4% of adult cases were intentional exposures, and of these 64.3% were females. There was a predominance of accidentalexposures (98.8%) and a male predominance (59.7%) in children. Categories of poisoning exposures across all age groups were non-drugchemicals (52.7%), medicines (35.2%) and biological toxins (12.6%). Pesticides (34.8%), irritant/corrosive substances (27.7%) and volatilehydrocarbons (8.3%) were the most common classes of non-drug chemical exposures. Cholinesterase inhibitors (8.8%), anticoagulant rodenticides (7.1%) and pyrethroids (5.0%) were the most commonly ingested non-drug chemicals. Aldicarb and amitraz poisoning were identified as toxicovigilance targets. Analgesics (26.1%) were the most common class of medicine-related exposure, and paracetamol (15.8%), benzodiazepines (9.2%) and antihistamines (5.2%) were the most common medicine-related exposures.Conclusion. The study provided information on evolving trends and identified toxicovigilance targets and the need for continuing toxicology education programmes

In vitro neuroprotective potential of four medicinal plants against rotenone-induced toxicity in SH-SY5Y neuroblastoma cells

BACKGROUND: Lannea schweinfurthii, Zanthoxylum capense, Scadoxus puniceus and Crinum bulbispermum are used traditionally to treat neurological disorders. The aim of this study was to evaluate the cytoprotective potential of the four plants, after induction of toxicity using rotenone, in SH-SY5Y neuroblastoma cells. METHODS: Cytotoxicity of the plant extracts and rotenone was assessed using the sulforhodamine B (SRB) assay. Fluorometry was used to measure intracellular redox state (reactive oxygen species (ROS) and intracellular glutathione content), mitochondrial membrane potential (MMP) and caspase-3 activity, as a marker of apoptotic cell death. RESULTS: Of the tested plants, the methanol extract of Z. capense was the least cytotoxic; LC(50) 121.3 ± 6.97 μg/ml, while S. puniceus methanol extract was the most cytotoxic; LC(50) 20.75 ± 1.47 μg/ml. Rotenone reduced intracellular ROS levels after 24 h exposure. Pre-treating cells with S. puniceus and C. bulbispermum extracts reversed the effects of rotenone on intracellular ROS levels. Rotenone exposure also decreased intracellular glutathione levels, which was counteracted by pre-treatment with any one of the extracts. MMP was reduced by rotenone, which was neutralized by pre-treatment with C. bulbispermum ethyl acetate extract. All extracts inhibited rotenone-induced activation of caspase-3. CONCLUSION: The studied plants demonstrated anti-apoptotic activity and restored intracellular glutathione content following rotenone treatment, suggesting that they may possess neuroprotective properties

Spectrum of snake bite in the southern regions of South Africa: A retrospective analysis

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Amitraz Poisoning in South Africa: An analysis of cases over the past 5 years.

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Plant poisonings: The Tygerberg experience

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Amitraz Poisoning in South Africa: An analysis of cases over the past 5 years.

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