Neuroprotective flavonoids of the leaf of Antiaris africana Englea against cyanide toxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Different parts of Antiaris africana Englea (Moraceae) are used traditionally for the treatment of various diseases, including epilepsy and other nervous system disorders.

AIMS OF THIS STUDY

The current study was designed to evaluate the neuroprotective activity of flavonoids isolated from A. africana against potassium cyanide (KCN)-induced oxidative damage in brain homogenate.

MATERIALS AND METHODS

Dried and ground leaves of A. africana were extracted with methanol and fractioned into n-hexane (HFA), dichloromethane (DFA), ethyl acetate (EFA) and methanol (MFA). Each fraction was assessed for neuroprotective potential by anticholinesterase activity test. The fraction with the best anticholinesterase activity was subjected to various chromatographic techniques through bioassay-guided fractionation to isolate the bioactive compounds. The protective ability of the extract, fractions and compounds against Potassium cyanide (KCN)-induced mitochondrial damage in rat brain homogenate was evaluated. Structures of the isolated compounds were determined using 1D and 2D NMR, mass spectrometry and by comparison with literature data.

RESULTS AND DISCUSSION

The ethyl acetate fraction showed the best anticholinesterase activity with an IC₅₀ of 23.23 ± 1.12 μg/ml. Quercetin and a biflavonoid glucoside identified as 3'-4'-bisquercetin-3β-D-diglucoside from this fraction displayed a remarkable antioxidant activity in the DPPH assay and showed significant (P < 0.05) increase in the activity of dehydrogenase inhibited by KCN in a concentration dependent manner. However, quercetin was more effective in reducing the MDA level and acetylcholinesterase activity that were elevated by KCN.

CONCLUSION

Quercetin and the bisquercetin-diglucoside isolated from the leaves of A. Africana for the first time, are major contributors to the observed neuroprotective property of the plant which supports its folkloric usage in the management of seizures, epilepsy and other neurological disorders.

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.

Distribution of iridiod glucosides and anti-oxidant compounds in Spathodea campanulata parts

The antioxidant principles isolated from the various parts of the plant are verminoside (leaf, stem bark and flowers; EC(50) = 2.04 µg/ml), Specioside (flowers; EC(50) = 17.44 µg/ml), Kampeferol diglucoside (leaf; EC(50) = 8.87 µg/ml) and Caffeic acid (leaf and fruits). The non anti-oxidant components isolated in the study include ajugol (stem bark and fruits) and phytol (leaf).

New glucose esters from the fresh leaves of Jacaranda mimosaefolia

From the fresh leaves of Jacaranda mimosaefolia were isolated Phytoquinoids 1-4 established as beta-D-glucopyranose 2-benzeneacetatel,6-bis(1-hydroxy-4-oxo-2,5-cyclohexadiene-1-acetate), for which the name Jacaranoside is proposed; beta-D-glucopyranose 2-(4-hydroxybenzeneacetate) 1,6-bis(1-hydroxy-4-oxo-2,5-cyclohexadiene-1-acetate), for which the name Jacarandol is proposed; beta-D-glucopyranose 2-benzeneacetate 1-(1-hydroxy-4-oxo-2,5-cyclohexadiene-1-acetate) and beta-D-glucopyranose 1,6-bis (1-hydroxy-4-oxo-2,5-cyclohexadiene-1-acetate) respectively.

New Glucose Esters from the Fresh Leaves of Jacaranda mimosaefolia

From the fresh leaves of Jacaranda mimosaefolia were isolated Phytoquinoids 1-4 established as β-D-glucopyranose 2-benzeneacetate1,6-bis(1-hydroxy-4-oxo-2,5-cyclohexadiene-1-acetate), for which the name Jacaranoside is proposed; β-D-glucopyranose 2-(4-hydroxybenzeneacetate) 1,6-bis(1-hydroxy-4-oxo-2,5-cyclohexadiene-1-acetate), for which the name Jacarandol is proposed; β-D-glucopyranose 2-benzeneacetate 1-(1-hydroxy-4-oxo-2,5-cyclohexadiene-1-acetate) and β-D-glucopyranose 1,6-bis (1-hydroxy-4-oxo-2,5-cyclohexadiene-1-acetate) respectively.

Antinociceptive and antiinflammatory effects of essential oil of Dennettia tripetala G.Baker (Annonaceae) in rodents

In this study we evaluated the analgesic and anti-inflammatory activities of the essential oil (EO) of the fruits of Dennettia tripetala in rodents. The plant is a tropical African plant and the fruits are commonly eaten as spices and consumed as a stimulant, and its various parts are used in the treatment of fever, cough and as anti-emetics.The analgesic effects of the oil was assessed in mice using the hot plate, acetic acid-induced writhings and formalin test, while carrageenan-induced paw oedema was used to study the antiinflammatory effects in rats. The EO at 25-50 mg/kg exhibited significant (p<0.05) antinociceptive effects comparable to a potent opioid agonist, morphine (10 mg/kg) and non-steroidal anti-inflammatory drugs such as, aspirin (100 mg/kg) and indomethacin (80 mg/kg). The antinociceptive effect of the EO was also blocked by naloxone (2 mg/kg) in all the models used. The EO demonstrated significant (p<0.05) anti-inflammatory effect in the carrageenan-induced paw oedema model of inflammation that is also comparable to dexamethasone (1 mg/kg) The results showed that the essential oil of D. tripetala possesses significant antinociceptive and antiinflammatory effects in the animal models used. The results also suggest that the analgesic effects may be mediated both centrally as well as peripherally, while the antiinflammatory activity may be effective in both early and late phases of inflammation. The results obtained may therefore be used to rationalize the use of the plant in the treatment of pain and fever in traditional medicine.

Clinical evaluation of Acalypha ointment in the treatment of superficial fungal skin diseases

In an open non-comparative study to evaluate the efficacy and safety of Acalypha wilkesiana ointment in superficial fungal skin diseases, 32 Nigerian patients with clinical and mycological evidence of superficial mycoses were recruited. Twelve patients defaulted and were lost to follow up, while one patient withdrew because of intolerable excoriation at the site of the lesion. Of the 19 patients that completed the trial, clinical cure was achieved in 73.3% of the patients. The ointment was very efficacious in the treatment of Tinea pedis, Pityriasis versicolor and Candida intetrigo where the cure rate was 100% in each condition. It is recommended that Acalypha ointment can be used for the treatment of these superficial mycoses.

S. K. Adesina, O. Idowu, A. O. Ogundaini, H. Oladimeji, T. A. Olugbade, G. O. Onawunmi and M. Pais, 'Antimicrobial constituents of the leaves of EAcalypha wilkesiana and acalypha hispida'. Phytotherapy research14(5) 2000, 371-374

The original article to which this Erratum refers was published in Phytotherapy Research 14(5) 2000, 371-374. Following publication of this paper in the August 2000 issue of Phytotherapy Research (14(5):371-374), it has come to our attention that the dates of receipt and acceptance were printed incorrectly. The corrected dates appear below. The publishers would like to apologise for any confusion caused. Received 28 August 1996 Accepted 15 June 1997

Prieurianoside, a protolimonoid glucoside from the leaves of Trichilia prieuriana

The ubiquitous glycolipid 1,2-dilinolenoyl-3-galactopyranosylglycerol and a new protolimonoid glucoside, named prieurianoside, were isolated from the leaves of Trichilia prieuriana. The structure of the latter was established, by spectroscopic techniques, as 12beta,21-diacetoxy-29-beta-D-glucopyranosyloxy-23zeta -hydroxytirucalla-7,24-dien-3-one.

Antimicrobial constituents of the leaves of Acalypha wilkesiana and Aacalypha hispida

An activity directed fractionation of a 50% aqueous ethanol extract of A. wilkesiana and A. hispida leaves resulted in the isolation of gallic acid, corilagin and geraniin as the compounds responsible for the observed antimicrobial activity. Quercetin 3-O-rutinoside and kaempferol 3-O-rutinoside were also isolated from the inactive fraction of A. hispida. The structures were established by permethylation, 2D - NMR ((1)H and (13)C) and MS data.

Antimicrobial constituents of the leaves of Acalypha wilkesiana and Aacalypha hispida

An activity directed fractionation of a 50% aqueous ethanol extract of A. wilkesiana and A. hispida leaves resulted in the isolation of gallic acid, corilagin and geraniin as the compounds responsible for the observed antimicrobial activity. Quercetin 3-O-rutinoside and kaempferol 3-O-rutinoside were also isolated from the inactive fraction of A. hispida. The structures were established by permethylation, 2D - NMR ((1)H and (13)C) and MS data.

Antimicrobial constituents of the leaves of Acalypha wilkesiana and Aacalypha hispida

An activity directed fractionation of a 50% aqueous ethanol extract of A. wilkesiana and A. hispida leaves resulted in the isolation of gallic acid, corilagin and geraniin as the compounds responsible for the observed antimicrobial activity. Quercetin 3-O-rutinoside and kaempferol 3-O-rutinoside were also isolated from the inactive fraction of A. hispida. The structures were established by permethylation, 2D - NMR ((1)H and (13)C) and MS data.

Petersaponins III and IV, triterpenoid saponins from Petersianthus macrocarpus

Two new triterpenoid saponins, petersaponins III and IV (1 and 2), were isolated from an n-butanol extract of the bark of Petersianthus macrocarpus. They possess 21-O-benzoyl-22-O-acetylbarringtogenol C and 21-O-2-furoxyl-22-O-tigloylbarringtogenol C as the aglycon, respectively. For both 1 and 2, the trisaccharide moiety linked to C-3 of the aglycon consists of D-glucuronic acid, D-xylose, and D-galactose, while a L-rhamnose unit is linked to C-28. The structures of 1 and 2 were elucidated by extensive NMR experiments including (1)H-(1)H (COSY, HOHAHA, NOESY) and (1)H-(13)C (HMQC and HMBC) spectroscopy and by chemical evidence.

New amides from Zanthoxylum lemairie pericarps

Two new aromatic amides were isolated from the pericarps of Zanthoxylum lemairie. The structures were elucidated by spectroscopic methods and confirmed by synthesis. A known aromatic amide, zanthosinamide, and four dibenzylbutyrol-actone lignans were isolated.

Pharmacokinetics and bioavailability of drotaverine in humans

The pharmacokinetics and bioavailability of drotaverine was studied in 10 healthy volunteers after administration of single 80 mg oral and intravenous doses of the HCl salt of the drug, in a crossover fashion. Plasma and urine samples were analyzed for the unchanged drug by HPLC. The pharmacokinetic parameters, such as elimination half-life, plasma clearance, renal clearance and apparent volume of distribution, were not influenced by the route of drug administration. The drug was mainly eliminated by non-renal routes since renal clearance accounted for only 0.31 +/- 0.13% of the total plasma clearance. The absolute bioavailability was variable and ranged from 24.5-91% with a mean of 58.2 +/- 18.2% (mean +/- SD). It is suggested that the high variation in the bioavailability of drotaverine HCl after oral administration may result in significant interindividual differences in therapeutic response.