Em Obuotor

Pharmacological properties of the extract and some isolated compounds of Clausena lansium stem bark: Anti-trichomonal, antidiabetic, anti-inflammatory, hepatoprotective and antioxidant effects

ETHNOPHARMACOLOGICAL RELEVANCE Clausena lansium (Fools Curry Leaf) is used for various ethnomedical conditions in some countries, including bronchitis, malaria, viral hepatitis, acute and chronic gastro-intestinal inflammation, and as a spicy substitute of the popular Curry leaf tree (Murraya koenigii). AIM OF THE STUDY This study was to evaluate the ethnomedical uses of the stem bark in inflammatory conditions, hepatotoxicity and to determine the anti-diabetic and anti-trichomonal properties of the plant. MATERIALS AND METHOD Anti-trichomonal, in vivo and in vitro antidiabetic and insulin stimulating, anti-inflammatory, hepatoprotective and anti-oxidant activities using Trichomonas gallinae, glucose loaded rats and in vitro insulin secreting cell line (INS-1 cell), carrageenin-induced rat paw oedema, CCl(4)-induced hepatotoxicity and DPPH scavenging ability methods respectively for the extracts and some isolates were determined. RESULTS A dichloromethane extract was superior over methanolic extract with respect to an anti-trichomonal activity which was measured after 24 and 48 h. The isolated compounds imperatorin and 3-formylcarbazole had the main anti-trichomonal activity (LC(50)s of 6.0, 3.0 and 3.6, 9.7 microg/mL after 24 and 48 h, respectively). Methanolic extract (100 mg/kg) induced maximum and significant (p<0.05) anti-hyperglycaemic activity of 15.8% at 30 min and a 38.5% increase in plasma insulin at 60 min, compared to control. The increase in plasma insulin after 60 min, compared to 0 min, was 62.0% (p<0.05). The significant 174.6% increase of insulin release from INS-1 cells (in vitro) at 0.1 mg/ml indicates that it mediates its antidiabetic action mainly by stimulating insulin release. Imperatorin and chalepin were the major active constituents increasing in vitro insulin release to 170.3 and 137.9%, respectively. 100 mg/kg of the methanolic extract produced an anti-inflammatory activity after 4 h. A sedative effect was not observed. 100 and 200 mg/kg of methanolic extract administered i.p., reduced CCl4-induced hepatotoxicity firstly by 5.3 and 8.4% reduction in phenobarbitone-sleeping time respectively, secondly by reversing the reduction in serum liver proteins by 7.0-8.8%, serum AST, ALT and ALP activities by 27.7-107.9% and thirdly by diminishing increased values of plasma AST, ALT and ALP activities by 13.2-83.8%. The extract exhibited antioxidant activities. CONCLUSION The hepatoprotective activity of C. lansium is partly due to its anti-oxidant and anti-inflammatory properties and confirms its folkloric use in the treatment of gastro-intestinal inflammation, bronchitis and hepatitis. In addition the use of C. lansium stem bark would be useful in diabetes and trichomoniasis.

Memory enhancing, anticholinesterase and antimicrobial activities of β-phenylnitroethane and essential oil of Dennettia tripetala Baker f

ETHNOPHARMACOLOGICAL RELEVANCE Dennettia tripetala Baker f. belonging to the family Annonaceae is an important food and medicinal plant used in some local communities in Southwest Nigeria. AIMS OF THE STUDY The study aims at determining the chemical composition of the essential oil of different morphological parts of D. tripetala, the memory enhancing and anticholinesterase activities as well as the antimicrobial properties. MATERIALS AND METHODS Essential oil of the morphological parts namely the fresh fruits, dried fruits, dried seeds and fresh leaves were obtained by hydrodistillation and analysed by GC-FID and GC-MS. The oil samples were evaluated for memory enhancement using Y-maze and in vitro anticholinesterase activities. The antimicrobial properties were also evaluated by nutrient broth method. RESULTS GC analysis identifies β-ocimene, linalool, β-phenylnitroethane and humulene as common constituents of the fresh fruits, dried fruits, dried seeds and fresh leaves. β-Phenylnitroethane (BPNE) was the predominant constituent of all the parts; with the dried seed containing 87.4% BPNE, followed by the dried fruit (78.1%), fresh leaf (62.9%) and the fresh fruit content was 61.6%. The second most predominant constituent, linalool, was highest in the fresh fruit (29.9%), followed by the fresh leaf (16.0%), the dried fruit (14.9%) and the dried seed had least linalool content (8.8%). (Z)- β-Ocimene and humulene were other common components. The seed oil and BPNE exhibited high memory enhancing activities in the Y-maze test. However, the seed oil exhibited the best inhibition against the test bacteria and it had a broad spectrum of antimicrobial activity. Bioactivities demonstrated by the various essential oils were not solely due to BPNE; rather, synergistic effects of other components are quite obvious. CONCLUSION The most abundant component - β-phenylnitroethane of D. tripetala was totally responsible for its memory enhancing properties but could not solely account for its antimicrobial activity.

Acute and Sub-Chronic toxicity potential effects of Alchornea Cordifolia (Euphorbiaceae) in rats

Alchornea cordifolia (Euphorbiaceae) is a plant that has been shown to have considerable activity against a broad spectrum of bacteria including those that have developed resistance to several antibiotics. In view of the high prevalence of antibiotic resistant bacteria, the search for new effective antimicrobial substances is urgent and must be extended to higher plants such as A. cordifolia . A useful antimicrobial substance must however have a defined toxicity profile which is why this attempt was thought to be worthy of serious consideration. Both oral acute and sub-chronic toxicity studies were carried out in rats. Acute toxicity study revealed that the ethanolic extract has no significant effect on both Packed cell volume (PCV) and Hemoglobin (Hb) and biochemical parameters. Similarly, the sub-chronic administration had no significant effect on hematological parameters and biochemical parameters such as protein, total cholesterol, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and glutathione (GSH), however, triglyceride (TG) and lactate dehydrogenase (LDH) were significantly increased at the dose of 250 mg/kg/day when compared with the vehicle-treated rats. Furthermore, there was a significant increase in protein, TG and LDH at the dose of 500 mg/kg/day when compared with the dose of 250 mg/kg/day. Histopathological results revealed that there were no significant changes in the organs of the treated animals when compared with vehicle-treated group. The open field test showed that sub-chronic administration increased rearing behavior significantly at the dose of 250 mg/kg/28 days but had no effect on grooming. In conclusion, the ethanolic extract has no toxicological effect as observed on hematological, biochemical and histopathological parameters even at the maximum dose administered suggesting that the plant ethanolic leaf extract is devoid of any toxicity effects.