STANDARDIZATION AND TOXICOLOGICAL STUDIES OF THE LEAF OF SENNA SIAMEA IRWIN & BARNEBY (FABACEAE) COLLECTED FROM AGULU IN AWKA SOUTH OF ANAMBRA STATE

Abstract

Background: Pharmacognostic standards and toxicological studies of the leaf of S. siamea were carried out. Objectives: To determine the quantitative phytochemical constituents present, pharmacognostic standards and  toxicological effect of the methanol leaf extract and fractions of S. siamea. Methodology: Fresh leaves of S. siamea were collected, dried, pulverizes to powder and subjected to pharmacognostic and quantitative phytochemical analysis. The pulverized leaves were cold macerated in methanol for three days with intermittent shaking and exchange of fresh solvent every 24 hrs (aliquot extraction). Fractionation was done using n-hexane, ethylacetate and butanol. Chromatographic analysis of the methanol extract and fractions were obtained using standard methods. The methanol extract and fractions where screened for phytochemical constituents and toxicological effects using standard methods. Acute toxicity (LD₅₀) of the extract was determined  using Lorke’s method. Results: Macroscopic and microscopic examinatios revealed acute apex, pinnate veination and diacytic stomata, trichomes respectively. Phytochemical screening of the extract and fractions revealed the presence of flavonoids, alkaloids, saponins, tannins etc. Proximate analysis of S. siamea revealed moisture content of 5.50 %, total ash value of 15.00 %, water soluble ash of 2.00 % etc.  The LD₅₀ was found to be > 5000 mg/kg. Increase in ALT, AST and ALP when metanol extract and fractions were administered were not statistically different from the control group, indicating no hepatotoxic potential. Increase in PCV, Hb and RBC when metanol extract and fractions were administered were not statistically different from control group. The non-significant decrease in the levels of ALP, ALT and AST indicates that the extract has possible hepatoprotective effect. The non-significant decrease in the levels of RBC, Hb and PCV indicates that the extract does not affect the heamatopoietic system when administered orally and at the doses used in the study. Conclusions: Specific standards obtained from the study may be compiled into a monograph of S.siemea plant that may constitute in herbal pharmacopoeia.