The gastroprotective effect of ethyl acetate fraction of hot water extract of Trichosanthes cucumerina Linn and its underlying mechanisms.

BACKGROUND: Antacids, anticholinergic drugs, histamine H2- receptor antagonists and irreversible proton pump inhibitors have been used for the treatment of gastric ulcers. However, prolonged use of these drugs may lead to series of adverse effects such as diarrhea, headache, rash, hypertension, muscular and joint pain. Therefore, there is an urgent need of more effective and safer treatments with fewer side effects. The aim of the present study was to scientifically evaluate the gastroprotective activity of fractions of the hot water extract of Trichosanthes cucumerina Linn (Family: Cucurbitaceae) aerial parts with a view to identifying the fraction with the best gastroprotective activity and the possible mechanism/s by which this fraction exert gastroprotection. METHODS: Gastroprotective activity of hexane fraction (HF), ethyl acetate fraction (EF), butanol fraction (BF) and aqueous fraction (AF) were evaluated by the assessment of ability to reduce the ulcer index in ethanol-induced rat model and the mode of action by which the most active fraction mediating gastroprotection. RESULTS: EF showed the maximum gastroprotection effect followed by BF and AF. EF (75 mg/kg) exhibited significantly higher gastroprotection compared to the reference drugs. Further investigations with two lower doses of EF confirmed that EF can mediated a significant and dose dependent gastroprotection. The rats treated with the EF showed significant reduction in free acidity (45%), total acidity (by 48%) in the gastric juice, increased the amount of mucus produced by the rat gastro mucosa and potent antihistamine activity (by 25.6%). EF was also rich in phenolic compounds and flavonoids. CONCLUSION: Gastroprotective mechanism of EF is possibly involves inhibition of acidity, elevation in mucus content, inhibition of histamine and antioxidant mechanisms.

Detection of immunity in sheep following anti-rabies vaccination.

Purpose: Rabies is a fatal but preventable disease with proper pre-exposure anti-rabies vaccination (ARV). Dogs, as household pets and strays, are the reservoir and vector of the disease, and dog bites have been associated with human rabies cases in Sri Lanka over the past few years. However, other susceptible species having frequent contact with humans may be a source of infection. One such species is sheep and immunity following ARV has never been tested in sheep reared in Sri Lanka. Materials and Methods: We have tested serum samples from sheep reared in the Animal Centre, Medical Research Institute of Sri Lanka for the presence of anti-rabies antibodies following ARV. Sheep serum samples were tested with Bio-Pro Rabies enzyme-linked immunosorbent assay (ELISA) antibody kits used for the first time in Sri Lanka and our results were verified by a seroneutralization method on cells (fluorescent antibody virus neutralization, FAVN test) currently recommended by World Organization for Animal Health and World Health Organization. Results: Sheep received annual ARV and maintained high neutralizing antibody titers in their serum. No maternal antibodies were detected in lamb around 6 months of age. Agreement between the ELISA and FAVN test, i.e., coefficient concordance was 83.87%. Conclusion: Annual vaccination in sheep has an effect on maintaining adequate protection against rabies by measurements of anti-rabies antibody response. Lambs need to be vaccinated earlier than 6 months of age to achieve protective levels of neutralizing antibodies in their serum. Introducing this ELISA in Sri Lanka will be a good opportunity to determine the level of anti-rabies antibodies in animal serum samples.