In Vitro and In Vivo Effect of Xylopic Acid on Cytochrome P450 Enzymes.

INTRODUCTION: Xylopic acid (XA), the major constituent of the fruit of Xylopia aethiopica, has shown several pharmacological properties. Traditionally, the plant is used to treat several diseases and is being used in the preparation of several local foods despite the lack of information about its safety, food-drug interaction, and other pharmacokinetic properties. This study, therefore, investigated the effect of XA on rat liver cytochrome P450 (CYP) enzymes in vivo and in vitro. METHODS: Inhibition or induction of some isoforms of CYP450 enzymes: CYP 1A1/1A2, 1A2, 2B1/2B2, 3A4, 2D6, and 2C9 were investigated using microsomal fractions of the liver obtained from rats pretreated with a low dose of xylopic acid (LDT) 30 mg/kg, high dose of xylopic acid (HDT) 100 mg/kg, phenobarbitone (PC) 80 mg/kg, and ketoconazole (NC) 100 mg/kg, and a no-treatment group received distilled water, with (n = 5) animals in each group. The in vitro inhibition of CYP 3A4 was assessed by treating rat liver microsomes with XA. RESULTS: Xylopic acid induced CYP 1A1/1A2, 1A2, 2D6, and 2C9, inhibited CYP 3A4, and had no effect on 2B1/2B2. CONCLUSION: The findings would help mitigate toxicity and therapeutic failure especially in cases of coadministration of medications with food containing XA, with metabolism altered by the latter.

A Hydroethanolic Leaf Extract of Persicaria lanigera Possesses Antinociceptive Activity through Cytokine and Glutamatergic Pathways In Vivo.

Persicaria lanigera is used traditionally to treat pain. The antinociceptive properties of the hydroethanolic leaf extract of Persicaria lanigera (PLE) were evaluated in rats and mice. Mice were pretreated orally with PLE (30, 100, and 300 mg kg-1) and evaluated for antinociceptive effects in the acetic acid-, glutamate-, and formalin-induced nociception models. Additionally, mechanical hyperalgesia models were used to evaluate PLE's influence on TNF-α- and IL-1ß-induced hyperalgesia in rats. In the acetic acid-induced nociception model, 100 mg kg-1 PLE exhibited the highest antinociceptive activity of 95.13 ± 9.52% at p < 0.0001, followed by the 300 mg kg-1 (85.44 ± 5.75%; p < 0.0001) and then the 30 mg kg-1 (67.95 ± 18.55%; p < 0.01), compared to morphine 3 mg kg-1 i.p. (86.97 ± 9.52; p < 0.0001). PLE (30, 100, and 300 mg kg-1) also showed significant (p < 0.05) antinociceptive effect in phase two of the formalin-induced nociception with % inhibitions of 66.88 ± 12.17, 75.12 ± 9.01, and 89.12 ± 4.32%, respectively, compared to 3 mg/kg morphine (97.09 ± 2.84%). Similarly, PLE (30, 100, and 300 mg kg-1) significantly reduced pain in the glutamate-induced nociception model with % inhibitions of 79.28 ± 8.17, 90.54 ± 5.64, and 96.49 ± 1.43%, respectively, whereas ketamine (5 mg/kg i.p.) reduced nociception to be 59.94 ± 18.14%. All doses of PLE significantly reduced nociceptive scores in TNF-α- and IL-1ß-induced mechanical hyperalgesia (p < 0.01). Similarly, PLE significantly inhibited bradykinin-induced nociception. The hydroethanolic extract of Persicaria lanigera has antinociceptive effects; this is the first scientific report providing evidence to validate its traditional use for the management of pain.

Antinociceptive effect of the hydroethanolic leaf extract of Calotropis procera (Ait) R. Br. (Apocynaceae): Possible involvement of glutamatergic, cytokines, opioidergic and adenosinergic pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Pain remains real and still a major problem in clinical medicine which requires new agents with improved efficacy for more therapeutic benefits. Plant sources can serve as a basis for the search for some novel drugs hence the analgesic effects of the hydroethanolic extract of Calotropis procera (CPE) which is widespread in Ghana and other tropical areas and used in folkloric medicine for painful and inflammatory conditions was evaluated. MATERIALS AND METHODS: The analgesic properties of orally administered CPE at doses of 30, 100, and 300 mg/kg were evaluated in thermal (tail immersion), chemical (acetic acid-writhing, formalin-induced paw licking, glutamate-induced nociception) and mechanical (Randall-Selitto) tests for analgesia. The involvement of tumour necrosis factor-alpha (TNF-α), interleukin 1ß (IL 1ß), bradykinin, and prostaglandin E2 (PGE2) on the analgesic effects of CPE were also evaluated in hypernociception assays measuring mechanical pain thresholds. RESULTS: The latency of tail withdrawal in the tail immersion test was significantly increased (p = 0.0001) while writhing induced by acetic acid was significantly reduced (p < 0.0001) on treatment with CPE (30-300 mg/kg). The extract also significantly inhibited both phase 1 and phase 2 nociceptive states induced by formalin comparable to morphine (p < 0.0001). Furthermore, the extract significantly attenuated hyper-nociception induced by TNF-α (p < 0.0001), interleukin 1ß (p = 0.0102), bradykinin (p < 0.0001), and prostaglandin E2 (p < 0.0001). Additionally, glutamate-induced paw licking was reduced significantly (p < 0.05). The antinociceptive effects exhibited by CPE (100 mg/kg) in the formalin test was reversed by systemic administration of naloxone (2 mg/kg) and theophylline (5 mg/kg) but not glibenclamide (8 mg/kg), granisetron (2 mg/kg), atropine (3 mg/kg), yohimbine (3 mg/kg, p.o.) nor nifedipine (10 mg/kg). CONCLUSION: Overall, the hydroethanolic leaf extract of Calotropis procera possesses analgesic properties that is mediated possibly through the glutaminergic, opioidergic, and adenosinergic pathways.

Protective effect of bergapten in acetic acid-induced colitis in rats.

Bergapten (5-methoxysporalen) is a furanocoumarin extracted from several species of citrus and bergamot oil. Bergamot essential oil is used traditionally in the management of inflammatory conditions. Previous studies on bergapten have explored mainly its in vitro anti-inflammatory activities which include suppression of the expression and release of pro-inflammatory cytokines such as TNF-α and interleukins as well as prostaglandins. Bergapten enhances the clearance of neutrophils and macrophages from the site of inflammation and reduces oxidative stress by inhibition of reactive oxygen species (ROS). Bergapten was assessed for its anti-inflammatory properties in acetic acid-induced colitis. Animals were obtained and randomly placed in six (6) groups (n = 5) after acclimatization. Colitis was induced by rectal administration using 4% v/v acetic acid in Sprague Dawley rats after pre-treatment for 5 days. Bergapten was administered at doses of 3, 10, and 30 mg kg-1 p.o. while the control group received saline 5 mL kg-1 p.o. and the standard drug employed was sulphasalazine at a dose of 500 mg kg-1. Assessments made for colon-weight-to-length ratio, colonic injury, and mucosal mast cell degranulation. There were reduced colon-weight-to-length ratios in animals treated with bergapten which was significant (p < 0.5) for doses 10 and 30 mg kg-1 compared to the disease control group Both macroscopic and microscopic damage were reduced as well, with a lesser percentage of degranulated mast cells. Macroscopic damage was reduced for bergapten at doses 10 and 30 mg kg-1 significantly at p < 0.5 and p < 0.001, respectively. Similarly, microscopic damage was reduced at p < 0.01 and p < 0.001 respectively for bergapten 10 and 30 mg kg-1. The reduction of degranulation by bergapten was significant at p < 0.001. There was generally reduced damage at inflammatory sites as well as decreased infiltration of inflammatory cells. Overall, bergapten reduces inflammation in acetic acid-induced colitis.

Leaf and root bark extracts of Ziziphus abyssinica Hochst ex. A. Rich (Rhamnaceae) ameliorate hepatic, renal and splenic injuries induced by phenylhydrazine in rats.

Objectives Ziziphus abyssinica (ZA) is employed in managing several ailments in Traditional African Medicine. Scientific evaluations are necessary to ascertain the medicinal potential of ZA as a source of new drug molecules. This study investigated the possible therapeutic benefit of ZA leaf (ZAL) and root bark (ZARB) extracts in an experimental model of multi-organ injuries induced by phenylhydrazine (PHZ). Methods Hyperbilirubinaemia, hepatotoxicity, nephrotoxicity and splenic injuries were induced by pretreating albino rats with PHZ (40 mg/kg, p.o.) for two alternate days. Afterward, six out of the eight groups of rats (n = 5) used were treated with either ZAL or ZARB (30, 100 and 300 mg/kg/day, p.o.) for seven days. Naïve control rats received saline without PHZ whereas negative control group received saline after PHZ. After one week of treatment, rats were sacrificed and blood collected for assessment of haematological and biochemical parameters. Liver, kidney and spleen sections were processed for histology and examined under light microscope. Results Data indicate that PHZ significantly (p < 0.05) increased total bilirubin, serum alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen (BUN), creatinine and BUN/creatinine ratio whereas red blood cell count was significantly reduced. These anomalies were significantly reversed in rats treated with ZAL or ZARB. The therapeutic effect of the extracts was supported by photomicrographs of the liver, kidney, and spleen of rats which revealed recovery from PHZ-mediated pyknosis, glomerular degeneration and multiple splenic necrosis respectively. Conclusions Overall, data from this study suggest that ZA may be useful in multiple organ injuries associated with PHZ-like xenobiotic toxicity.

Isobolographic analysis of co-administration of two plant-derived antiplasmodial drug candidates, cryptolepine and xylopic acid, in Plasmodium berghei.

BACKGROUND: Increasing resistance to current anti-malarial therapies requires a renewed effort in searching for alternative therapies to combat this challenge, and combination therapy is the preferred approach to address this. The present study confirms the anti-plasmodial effects of two compounds, cryptolepine and xylopic acid and the relationship that exists in their combined administration determined. METHODS: Anti-plasmodial effect of cryptolepine (CYP) (3, 10, 30 mg kg-1) and xylopic acid (XA) (3, 10, 30 mg kg-1) was evaluated in Plasmodium berghei-infected male mice after a 6-day drug treatment. The respective doses which produced 50% chemosuppression (ED50) was determined by iterative fitting of the log-dose responses of both drugs. CYP and XA were then co-administered in a fixed dose combination of their ED50s (1:1) as well as different fractions of these combinations (1/2, 1/4, 1/8, 1/16 and 1/32) to find the experimental ED50 (Zexp). The nature of interaction between cryptolepine and xylopic acid was determined by constructing an isobologram to compare the Zexp with the theoretical ED50 (Zadd). Additionally, the effect of cryptolepine/xylopic acid co-administration on vital organs associated with malarial parasiticidal action was assessed. RESULTS: The Zadd and Zexp were determined to be 12.75 ± 0.33 and 2.60 ± 0.41, respectively, with an interaction index of 0.2041. The Zexp was significantly (P < 0.001) below the additive isobole indicating that co-administration of cryptolepine and xylopic acid yielded a synergistic anti-plasmodial effect. This observed synergistic antiplasmodial effect did not have any significant deleterious effect on the kidney, liver and spleen. However, the testis were affected at high doses. CONCLUSION: The co-administration of cryptolepine and xylopic acid produces synergistic anti-malarial effect with minimal toxicity.

Antiinflammatory properties of betulinic acid and xylopic acid in the carrageenan-induced pleurisy model of lung inflammation in mice.

This study investigated the antiinflammatory properties of betulinic acid (BA) and xylopic acid (XA) extracted from Margaritaria discoidea and Xylopia aethiopica, respectively. M. discoidea and X. aethiopica are plants native in Ghana and the West-African region and used traditionally to treat different pathologies including inflammatory conditions. The antiinflammatory effect of BA and XA was established by an in vivo assay using the carrageenan-induced pleural inflammation model in mice. Also, the ability of BA and XA to increase catalase, superoxide dismutase, glutathione levels and decrease lipid peroxidation level in reactive oxidative assays was assessed. In addition, the ability of XA and BA to prevent potential lung tissue damage was quantified. Pretreatment with BA and XA reduced significantly, signs of inflammation: neutrophil infiltration, oedema, and alveoli septal thickening in carrageenan-treated lung tissue. Additionally, BA or XA pretreatment lowered the degree of lipid peroxidation in the lung tissue while increasing the levels of catalase, superoxide dismutase, and glutathione in vivo. Comparatively, XA was more efficacious than BA in the prevention of lung tissue damage. BA and XA derived from X. aethiopica and M. discoidea possess antiinflammatory and in vivo antioxidant activities in mice pleurisy model. The effect of these compounds gives credence to the traditional use in the management of inflammatory conditions of the airway.

Anticonvulsant activity of Pseudospondias microcarpa (A. Rich) Engl. hydroethanolic leaf extract in mice: The role of excitatory/inhibitory neurotransmission and nitric oxide pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Pseudospondias microcarpa (A. Rich) Engl. is a plant used for managing various diseases including central nervous system disorders. AIM OF THE STUDY: This study explored the anticonvulsant activity of P. microcarpa hydroethanolic leaf extract (PME) as well as possible mechanism(s) of action in animal models. METHODS: Effects of PME was assessed in electroconvulsive (the maximal electroshock and 6-Hz seizures) and chemoconvulsive (pentylenetetrazole-, picrotoxin-, isoniazid-, 4-aminopyridine-, and strychnine-induced seizures) models of epilepsy. In addition, effect of the extract on the nitric oxide pathway and GABAA receptor complex was evaluated. RESULTS: The extract (30, 100 and 300mgkg-1, p.o.) significantly delayed the onset as well as decreased the duration and frequency of pentylenetetrazole-, picrotoxin- and strychnine-induced seizures. In addition, PME pre-treatment significantly improved survival in the 4-aminopyridine- and isoniazid-induced seizure tests. Furthermore, the extract protected against 6-Hz psychomotor seizures but had no effect in the maximal electroshock test. The anticonvulsant effect of PME (100mgkg-1, p.o.) was also reversed by pre-treatment with flumazenil, L-arginine or sildenafil. However, L-NAME or methylene blue (MB) augmented its effect. CONCLUSION: Results show that PME has anticonvulsant activity and may probably be affecting GABAergic, glycinergic, NMDA, K+ channels and nitric oxide-cGMP pathways to exert its effect.

Xylopia aethiopica fruit extract exhibits antidepressant-like effect via interaction with serotonergic neurotransmission in mice.

ETHNOPHARMACOLOGICAL RELEVANCE: Xylopia aethiopica has been used traditionally to treat some central nervous system disorders including epilepsy. AIM OF THE STUDY: Despite the central analgesic and sedative effects, there is little evidence for its traditional use for CNS disorders. This study thus assessed the antidepressant potential of Xylopia aethiopica ethanolic fruit extract (XAE). MATERIAL AND METHODS: Antidepressant effect was assessed in the forced swim test (FST) and tail suspension test (TST) models in mice. The role of monoamines in the antidepressant effects of XAE was evaluated by selective depletion of serotonin and noradrenaline, whereas involvement of NMDA/nitric oxide was assessed with NMDA receptor co-modulators; d-serine and d-cycloserine and NOS inhibitor, l-NAME. RESULTS: Xylopia aethiopica (30, 100, 300mgkg(-1)) dose dependently reduced immobility in both FST and TST. The reduced immobility was reversed after 5-hydroxytryptamine (5-HT) depletion with tryptophan hydroxylase inhibitor-p-chlorophenylalanine (pCPA) and after monoamine depletion with vesicular monoamine transporter inhibitor-reserpine. The observed antidepressant effect was not affected by catecholamine depletion with the tyrosine hydroxylase inhibitor, α-methyl-p-tyrosine (AMPT). Similarly XAE did not potentiate the toxicity of a sub-lethal dose of noradrenaline. XAE had a synergistic effect with the glycineB receptor partial agonist, d-cycloserine and nitric oxide synthase inhibitor, l-NAME. However established antidepressant effects of XAE were abolished by NMDA and NOS activation with d-serine and l-arginine. CONCLUSION: This study shows that Xylopia aethiopica has antidepressant potential largely due to effects on 5-HT neurotransmission with possible glutamatergic effect through the glycineB co-binding site and nitric oxide synthase inhibition.

Phytotherapy of experimental depression: Kalanchoe integra Var. Crenata (Andr.) Cuf Leaf Extract.

CONTEXT: Kalanchoe sp. have been used since 1921 for central nervous system (CNS) disorders such as psychosis and depression. It is known to possess CNS depressant effects. AIMS: To investigate the antidepressant properties of the aqueous leaf extract of Kalanchoe integra. SETTINGS AND DESIGN: The study was carried out at the Kwame Nkrumah University of Science and Technology between 6 a.m. and 3 p.m. MATERIALS AND METHODS: ICR mice were subjected to the forced swimming test (FST) and tail suspension test (TST) after they had received extract (30-300 mg/kg), fluoxetine (3-30 mg/kg), desipramine (3-30 mg/kg) orally, or water (as vehicle). In a separate experiment, mice were pre-treated with reserpine (1 mg/kg), α-methyl paratyrosine (AMPT; 400 mg/kg), both reserpine (1 mg/kg) and AMPT (200 mg/kg) concomitantly, or p-chlorophenylalanine (pCPA; 200 mg/kg) to ascertain the role of the noradrenergic and serotoninergic systems in the mode of action of the extract. STATISTICAL ANALYSIS USED: Means were analyzed by analysis of variance (ANOVA) followed by Newman-Keuls' post hoc test. P < 0.05 was considered significant. RESULTS: In both FST and TST, the extract induced a decline in immobility, indicative of antidepressant-like effect. This diminution in immobility was reversed by pCPA, but not by reserpine and/or AMPT. The extract increased the swimming and climbing scores in the FST, suggestive of possible interaction with serotoninergic and noradrenergic systems. In the TST, the extract produced increases in both curling and swinging scores, suggestive of opioidergic monoaminergic activity, respectively. CONCLUSIONS: The present study has demonstrated the antidepressant potential of the aqueous leaf extract of K. integra is mediated possibly by a complex interplay between serotoninergic, opioidergic, and noradrenergic systems.