Pharmacodynamic studies on the isolated active fraction of Acacia farnesiana (L.) willd.

BACKGROUND: Acacia farnesiana is a medicinal plant that grows throughout tropical parts of Indian subcontinent, particularly in sandy soils of river beds in Northern India. The objective of the present study was to evaluate the anti-hyperglycemic activity of the extracts using glucose tolerance test. Isolation of an active fraction (AF) from the active extract (water extract) using alcohol precipitation and to get insight to the mechanism of action of the AF of A. farnesiana. MATERIALS AND METHODS: Glucose uptake by isolated rat diaphragm of the AF was performed. Further the effect of release of Insulin from isolated and cultured pancreatic ß-cell was determined. Besides, effect of oral administration of the AF was compared with that of intraperitonial administration. The effect of AF on serum glucose levels in orally glucose loaded rats was compared with that of intraperitoneal glucose loaded rats. RESULTS: The water extract significantly lowered the blood glucose level. When precipitated with alcohol, the activity was found in the soluble fraction. Glucose uptake in the isolated rat hemidiaphragm, was increased by the AF at 40 µg/ml concentration, the AF did not significantly influence insulin release from cultured islets. The AF was found to be effective in orally glucose loaded in contrast to intraperitonial route. CONCLUSION: Our findings suggest that this plant is promising for further studies leading to the development of valuable medicine for diabetes.

Anti-diabetic activity of active fractions of Stereospermum tetragonum DC and isolation of active principles.

OBJECTIVES: To identify the active principles, determine the anti-diabetes activity of fraction of Stereospermum tetragonum root. MATERIALS AND METHODS: The efficacy was evaluated in streptozotocin induced type 2 diabetic rats and the anti-hyperglycemic activity was studied by glucose tolerance test. The major active compounds were isolated by solvent fractionation and chromatographic techniques and characterized with spectral data. RESULTS: The active fraction of S. tetragonum showed presence of anti-diabetes mellitus activity in type-2 diabetic rats. It did not significantly influence insulin release from cultured islets. Two active principles (active at 2 mg/kg dose) were isolated and characterized with spectral data. One of them was identified as an iridoid type glycoside and the other one was a lapachol like compound (derivative of naphthoquinone). CONCLUSIONS: Two active principles from the anti-diabetes fraction of S. tetragonum root were isolated and identified as an iridoid glycoside and a naphthoquinone derivative.

Chlorophyll revisited: anti-inflammatory activities of chlorophyll a and inhibition of expression of TNF-α gene by the same.

In view of the folklore use of green leaves to treat inflammation, the anti-inflammatory property of chlorophylls and their degradation products were studied. Chlorophyll a and pheophytin a (magnesium-free chlorophyll a) from fresh leaves showed potent anti-inflammatory activity against carrageenan-induced paw edema in mice and formalin-induced paw edema in rats. Chlorophyll a inhibited bacterial lipopolysaccharide-induced TNF-α (a pro-inflammatory cytokine) gene expression in HEK293 cells, but it did not influence the expression of inducible nitric acid synthase and cyclooxygenase-2 genes. Chlorophyll b only marginally inhibited both inflammation and TNF-α gene expression. But both chlorophyll a and chlorophyll b showed the same level of marginal inhibition on 12-O-tetradecanoyl-phorbol-13-acetate-induced NF-κB activation. Chlorophylls and pheophytins showed in vitro anti-oxidant activity. The study shows that chlorophyll a and its degradation products are valuable and abundantly available anti-inflammatory agents and promising for the development of phytomedicine or conventional medicine to treat inflammation and related diseases.

Antipyretic, analgesic, anti-inflammatory and antioxidant activities of two major chromenes from Melicope lunu-ankenda.

AIM OF THE STUDY: Melicope lunu-ankenda (Gaertn.) T.G. Hartley is used in Indian traditional medicine for fever, improving complexion and as a tonic. Previous studies have isolated fungicidal, antifeedant, anti-inflammatory and immunomodulatory compounds from Melicope lunu-ankenda. This study is aimed at the isolation and biological activity screening of potential molecules from the volatile oils and extracts of Melicope lunu-ankenda in the light of traditional applications. MATERIALS AND METHODS: Volatile oil of Melicope lunu-ankenda leaves was isolated by hydrodistillation, characterized by GC-FID, GC-MS, LRI determination, Co-GC and database searches. Major chromene-type compounds in Melicope lunu-ankenda leaf oil, evodione and leptonol, were isolated by preparative TLC and characterized by UV-Vis, IR, 1H-, 13C-, 13C-DEPT NMR and EIMS. They were also isolated from the petroleum ether and acetone extracts of the leaves of Melicope lunu-ankenda by column chromatography in petroleum ether-ethyl acetate. Their contents in leaf oil, leaf and inflorescence extracts were estimated by HPTLC. Antipyretic (Baker's yeast-induced fever test), analgesic (acetic acid-induced writhing, tail immersion assays), anti-inflammatory (carrageenan-induced paw edema) and in vitro antioxidant (DPPH radical, superoxide radical scavenging) activities of evodione and leptonol were tested. RESULTS AND CONCLUSIONS: Gas chromatographic analyses found 50.7% monoterpene hydrocarbons, 0.4% oxygenated monoterpenes, 3.2% sesquiterpene hydrocarbons, 0.7% oxygenated sesquiterpenes and 43.7% chromene-type compounds in Melicope lunu-ankenda leaf oil, with evodione (20.2%) and leptonol (22.5%) as its two major constituents. HPTLC estimations in the petroleum ether, acetone extracts (leaf, inflorescence) and leaf oil found evodione 1.0% (dr. wt., leaf), 1.1% (inflorescence), 0.04% (fr. wt. leaves, leaf oil), and leptonol 0.3% (leaf), 0.3% (inflorescence) and 0.04% (leaf oil). Leptonol (200 mg/kg) showed good antipyretic activity. DPPH radical scavenging assay found moderate activity for leptonol (68.7%, 500 microM), whereas evodione showed near-zero activity. A very similar trend was found in superoxide radical scavenging activity of leptonol (64.5%) and evodione (10.3%), both at 100 microg/ml. Evodione and leptonol showed moderate analgesic activities in acetic acid-induced writhing and tail immersion assays. Moderate anti-inflammatory activity was found for both evodione (59.4%) and leptonol (49.0%) at 100 mg/kg. ETHNOPHARMACOLOGICAL RELEVANCE: Biological activities of evodione and leptonol isolated from Melicope lunu-ankenda justify its traditional uses as a remedy for fever, inflammation and as a tonic.

Studies on the antihyperlipidemic properties of Averrhoa bilimbi fruit in rats.

Averrhoa bilimbi Linn. fruit and its extracts were screened for antihypercholesterolemic activity using Triton-induced hypercholesterolemia in rats as a model. The fruit and its water extract, but not alcohol and hexane extracts, showed remarkable antihypercholesterolemic activity. An active fraction, which showed activity at a low dose of 0.8 mg/kg, was purified from the water extract. An active component was isolated from the active fraction, which showed optimum activity at a dose of 0.3 mg/kg. The efficacy of the fruit was tested in chronic high-fat diet fed hyperlipidemic rats. The fruit (125 mg/kg) as well as its water extract (50 mg/kg) were found to be effective in lowering lipids in the high-fat diet fed rats. The fruit was subjected to preliminary general toxicity evaluation in mice. Oral administration of the fruit homogenate daily for 15 days did not result in any toxic symptoms up to a dose of 1 g/kg studied. Thus, this fruit can be used as a dietary ingredient to prevent as well as treat hyperlipidemia.