Bioassay guided fractionation, isolation and characterization of hepatotherapeutic 1, 3-di-ortho-galloyl quinic acid from the methanol extract of the leaves of Pterocarpus santalinoides.

ETHNOPHARMACOLOGICAL RELEVANCE: Leaf extracts of Pterocarpus santalinoides DC are traditionally used to ameliorate ageing-related ailments such as heart and liver diseases, and have been reported to be protective against toxic injuries to the liver. AIM OF THE STUDY: This study aimed to isolate and characterize the hepatoprotective/hepatotherapeutic principle in the methanol leaf extract of P. santalinoides. MATERIALS AND METHODS: Fresh leaves of P. santalinoides were dried under shade and ground into powder. The ground leaves (2 Kg) were extracted with 80% methanol by maceration. Fractionation was carried out using column and thin layer chromatography techniques. Bioassay of fractions and sub-fractions was done using carbon tetrachloride (CCl4)-induced hepatotoxicity model in albino rats. Phytochemical analysis was carried out on the active compound. Characterization and structural elucidation of the active compound using high performance liquid chromatography and nuclear magnetic resonance spectroscopy was done. RESULTS: Extraction yielded 260 g dry extract. Six fractions (F1, F2, F3, F4, F5 and F6) were obtained after column and thin layer chromatography, with F6 (Rf = 0.78; Yield = 2.13 g) being the most active hepatotherapeutic fraction that significantly (p < 0.05) lowered serum ALT activity and increased serum albumin levels in CCl4-induced hepatopathy in albino rats. Further separation of F6 yielded four sub-fractions (F61, F62, F63 and F64), of which F61 with an Rf of 0.85 and a yield of 30.0 mg was isolated as the active hepatotherapeutic compound. Stiasny and ferric chloride test of F61 showed the presence of tannins in the fraction. Characterization of F61 revealed 1, 3-di-ortho-galloyl quinic acid. CONCLUSION: The hepatoprotective/hepatotherapeutic principle in the methanol extract of the leaves of P. santalinoides was identified as 1, 3-di-ortho-galloyl quinic acid.

Acute toxicity and hepatotoxicokinetic studies of Tamarindus indica extract.

Tamarindus indica is widely used as a food and beverage and in traditional medicine. The apparent lack of dose standardization in herbal medicine necessitates the evaluation of the lethality T. indica on Artemia salina nauplii and chicken embryos via in vitro and in vivo techniques. Furthermore, hepatotoxicokinetics of the crude extract and fractions on Wister rats was also assessed. At concentrations of 200, 20 and 2 µg/mL, crude extract and fractions showed brine shrimp death percentages ranging from 86.70% to 3.30% and the sub-fractions showed death percentage ranges of 46.70% to 3.30%. Calculated LD50 values ranged from 832 µg/mL to 5,019 µg/mL. Dosing Wister rats with 25% and 50% concentration of LD50 determined for crude extract and fractions on chicken embryos showed an elevation in the ALT and AST levels in the serum. Brine shrimps and chicken embryos showed a positive correlation, with R² values of 0.541 and 0.588 (P ≤ 0.05) for fractions and subfractions, respectively, as media for the lethality assay. Dose standardization in folk herbal medicine is imperative as T. indica used as food and medicine has been shown to be toxic at high doses. Brine shrimp and chicken embryos may be comparably used as medium for toxicity assay.

Potential antidiabetic and antioxidant activities of a heliangolide sesquiterpene lactone isolated from Helianthus annuus L. leaves.

Heliangolide is a naturally occurring sesquiterpene lactone and its derivatives are biologically active compounds present in most medicinal plants. This study evaluated the antioxidant and antidiabetic properties of a heliangolide sesquiterpene lactone isolated from Helianthus annuus L. leaves. The heliangolide sesquiterpene lactone was isolated through a combination of solvent-solvent partitioning, column chromatography, thin layer chromatography and high-performance liquid chromatography techniques. The antioxidant activity of the compound was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and nitric oxide radical scavenging assays while the antidiabetic effects were investigated in alloxan-induced diabetic rats. The heliangolide derivative at the concentration of 954.2 µmol L-1 showed 23.7 % DPPH and 26 % nitric oxide radical inhibitions compared with 96.6 and 50.9 %, resp., displayed by the controls (2,271.2 µmol L-1). It also reduced the fasting blood glucose (FBG) levels in a time-dependent manner. The highest activity was recorded within 6 h post-treatment at 0.2 mmol kg-1 bm. The heliangolide derivative exhibited significant (p < 0.05) antioxidant and antidiabetic properties and provides a basis for further development of constituents of Helianthus annuus leaves for the management of such diseases.

Acute and sub-chronic toxicity profile of methanol leaf extract of Gouania longipetala in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Gouania longipetala leaves are commonly used in folkloric medicine in Africa and other parts of the world for treatment of edema, febrifuges, veneral diseases, lumbago, heart diseases, diabetes mellitus malaria, etc. This study therefore evaluated safety profile of the methanol leaf extract of the plant using acute and sub-chronic studies in rat model. MATERIALS AND METHODS: Acute toxicity test of the plant lasted for 48 h with oral administration of graded doses (100-4000 mg/kg) of Gouania longipetala extract (GLE) in rats. The rats were observed for signs of toxicity and death. The sub-chronic toxicity was evaluated by administration of different doses (2.5, 5 and 10 mg/kg) of GLE daily in feed for 90 days. On days, 30, 60 and 90, blood samples collected from the retro-orbital plexus of the eye of the rats were used for evaluation of serum biochemistry, hematology, lipid peroxidation and in vivo antioxidant activities. Histopathological evaluations of the kidney, liver, lungs and heart were also done. RESULTS: The acute toxicity test revealed no observable signs of toxicity or morbidity. Sub-chronic study showed that GLE significantly (p<0.05) increased relative liver weight on day 90 at 10 mg/kg. There were no significant variations in the hematological parameters of both GLE treated and untreated rats. The extract significantly (p<0.05) reduced total cholesterol, triglycerides, very low density lipoproteins and increased high density lipoproteins which was more prominent on day 90 at the dose of 10 mg/kg. The extract significantly (p<0.05) increased liver enzyme markers at the doses used. GLE also significantly (p<0.05) increased serum urea at the dose of 10 mg/kg on day 90. The extract caused dose-dependent and significant (p<0.05) increase in superoxide dismutase and decrease in malondiadehyde. Histopathological studies revealed degenerative changes in the kidney and liver. CONCLUSION: The results of the study suggest that Gouania longipetala is well tolerated in short term therapies, but may have long term toxic effects on the kidney and liver.

Anti-ulcerogenic activity of the methanol root bark extract of Cochlospermum planchonii (Hook f).

Cochlospermum planchonii (Hook f) is a common medicinal plant used in Nigeria traditional medicine for treatment of different ailments including ulcers. The anti ulcer activity of the root bark methanol extract of Cochlospermum planchonii was evaluated using different [ethanol, acetylsalicylic acid (aspirin), cold/restraint stress and pyloric ligation/histamine - induced ulcers and acid production] ulcerogenic models in rats at the doses of 250, 500, and 1000 mg/kg body weight using cimetidine (100 mg/kg) as a standard reference drug. The different doses of the extract and the reference drug significantly (p < 0.01) decreased all the ulcer parameters in a dose dependent manner in all the models used. The total number of ulcers were significantly (p < 0.05) decreased. The ulcer index was significantly (p < 0.004) reduced by the extract. Similarly, the percentage ulcer preventive index was also increased from 0% in the negative control up to 93.2% at the dose of 1000 mg/kg, while the percentage ulcer severity was dose dependently reduced by the extract. Furthermore, the extract significantly (p < 0.02) decreased free gastric HCl and total gastric acid. In conclusion, Cochlospermum planchonii methanolic root bark extract showed significant antiulcer activity in this study which may be as a result of its cytoprotective, antioxidant or antisecretory properties.