Screening of phytochemical properties and antimicrobial activity of Malaysian medicinal plants against aquatic bacteria

Aims: Quantitative screening of phytochemical properties and antimicrobial activities were done on some plants of importance in human medicine as traditional herbs to treat fish diseases in Malaysia. Six extracts of Vitex trifolia, Aloe vera, Strobilanthes crispus, Clinacanthus nutans, Pereskia grandifolia and Peperomia pellucida were determined for phytochemical properties and their antibacterial activities against common freshwater pathogens i.e. Streptococcus agalactiae, Aeromonas hydrophila and Enterobacter cloacae. Methodology and results: Qualitative screening of phytochemical properties in herbs were determined using conversional method for flavonoids, tannins, saponin, alkaloids steroid and glycoside The results showed flavonoid was presence in all plant extracts. For the antimicrobial activity, the aqueous and methanolic extracts were tested by using disk diffusion method. Antimicrobial assay of methanolic crude extracts (25 to 100 mg/mL) showed effectiveness against the pathogenic bacteria. Comparatively, all aqueous extracts did not show any antimicrobial activity. Strong antibacterial activity was shown by the methanolic extracts of V. trifolia, A. vera and S. crispus while moderate antimicrobial activity was shown by C. nutans, P. grandifolia and P. pellucida. Conclusion, significance and impact study: The current results indicated that the studied plants might indeed be potential sources of natural antimicrobial agents to control fish diseases.

Subacute oral toxicity study of ethanolic leaves extracts of Strobilanthes crispus in rats

<p><b>OBJECTIVE</b>To examine the oral toxicity of repeated dosing of Strobilanthes crispus (S. crispus) ethanol leaves extract on the liver and kidney functions in Sprague Dawley rats.</p><p><b>METHODS</b>Young female rats aged between 8 and 12 week-old were randomly assigned into four groups with five animals each group (n=5). The first group served as control, while the second, third and fourth groups were orally treated with a single dose daily with 150 mg/kg, 300 mg/kg, and 600 mg/kg of S. crispus ethanol leaves extract for 14 d consecutively. Cage-side observation was conducted for first 4 h after each dosing. The body weight changes, food consumptions and water intake were also recorded. Serum biochemical parameters, i.e., aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatinine and urea were determined at Day 15. All results were expressed as mean±SD and analysed using Dunnett's test.</p><p><b>RESULTS</b>It was obtained that 14-day oral administration of S. crispus ethanol leaves extract did not cause any adverse effects or lethality to the female Sprague Dawley rats. No significant changes in serum biochemical parameters, relative organs weights, body weights, food intake and water consumptions were observed between the treatment groups and control.</p><p><b>CONCLUSIONS</b>In conclusion, 14-day oral administration of S. crispus ethanol leaves extract was safe to be consumed in female rats without affecting the liver and kidney functions.</p>

Subacute oral toxicity study of ethanolic leaves extracts of Strobilanthes crispus in rats

Objective:To examine the oral toxicity of repeated dosing of Strobilanthes crispus (S. crispus) ethanol leaves extract on the liver and kidney functions in Sprague Dawley rats. Methods:Young female rats aged between 8 and 12 week-old were randomly assigned into four groups with five animals each group (n=5). The first group served as control, while the second, third and fourth groups were orally treated with a single dose daily with 150 mg/kg, 300 mg/kg, and 600 mg/kg of S. crispus ethanol leaves extract for 14 d consecutively. Cage-side observation was conducted for first 4 h after each dosing. The body weight changes, food consumptions and water intake were also recorded. Serum biochemical parameters, i.e., aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatinine and urea were determined at Day 15. All results were expressed as mean±SD and analysed using Dunnett's test. Results: It was obtained that 14-day oral administration of S. crispus ethanol leaves extract did not cause any adverse effects or lethality to the female Sprague Dawley rats. No significant changes in serum biochemical parameters, relative organs weights, body weights, food intake and water consumptions were observed between the treatment groups and control. Conclusions:In conclusion, 14-day oral administration of S. crispus ethanol leaves extract was safe to be consumed in female rats without affecting the liver and kidney functions.