Tetracera alnifolia Willd. (Dilleniaceae) is used in traditional African Medicine for the treatment of headache, abdominal pain, and rheumatism. Hence, this study sought to investigate the antinociceptive and anti-inflammatory effects of the hydroethanolic leaf extract of T. alnifolia (HeTA) in rodents.
Antinociceptive activity was evaluated using the acetic acid-induced writhing, formalin-/capsaicin-induced paw licking and hot plate tests in mice. The contribution of opioidergic, l-arginine-nitric oxide, and ATP-sensitive potassium channel pathways in HeTA-induced antinociception was also evaluated. The anti-inflammatory effect was assessed using the carrageenan-induced paw edema, xylene ear edema, cotton pellet granuloma, and complete Freund’s adjuvant (CFA)-induced arthritis in rats.
HeTA (100, 200, and 400 mg/kg, p.o.) produced significant (p<0.05) decrease in mean number of acetic acid-induced writhing, time spent licking paw in formalin, and capsaicin tests as well as time course increase in nociceptive reaction latency in hot plate test. HeTA-induced antinociception was prevented by pretreatment of mice with naloxone (non-selective opioid receptor antagonist), l-arginine (nitric oxide precursor), or glibenclamide (ATP-sensitive potassium channel blocker). HeTA (100 mg/kg, p.o.) produced a significant anti-inflammatory effect against carrageenan-induced rat paw edema (1–5 h), xylene-induced ear edema, cotton pellet-induced granuloma formation, and CFA-induced arthritis in rats. The effects of HeTA in various models were similar to the effect of the standard reference drugs.
Findings from this study showed that HeTA possesses antinociceptive effect possibly mediated through peripheral opioid receptors with activation of l-arginine-nitric oxide and ATP-sensitive potassium channel pathway as well as anti-inflammatory activity.
Background: Mangifera indica (Anacardiaceae) is an important herb in the traditional African and Ayurvedic medicines. The stem barks are used in the treatment of hypertension, insomnia, tumour, depression, rheumatism and as a tonic. This study was carried out to investigate antidepressant- and anxiolytic-like effect of the hydroethanol stem bark extract of M. indica (HeMI) in mice.
Methods: HeMI (12.5–100 mg/kg, p.o.) was administered 1 h before subjecting the animal to the forced swim test (FST), tail suspension test (TST) and elevated plus maze tests (EPM).
Results: HeMI (12.5–100 mg/kg, p.o.) treatment produced significant reduction in immobility time [F(6.56)=8.35, p<0.001], [F(6,56)=7.55, p<0.001] in the FST and TST, respectively. Moreover, co-administration of sub-therapeutic doses of imipramine or fluoxetine with HeMI (3.125 mg/kg) elicited significant reduction in time spent immobile in the FST. However, pretreatment of mice with parachlorophenylalanine, metergoline, yohimbine or sulpiride abolished the antidepressant-like effect elicited by HeMI. In the EPM, HeMI produced significant [F(5,42)=8.91, p<0.001] increase in open arms exploration by 75.55 % and this effect was blocked by pretreatment of mice with flumazenil or metergoline.
Conclusions: Findings from this study showed antidepressant-like effect of M. indica through interaction with 5-HT2 receptor, α2-adrenoceptor and dopamine D2-receptors. Also, an anxiolytic-like effect through its affinity for 5-HT2 and benzodiazepine receptors. Hence, M. indica could be a potential phytotherapeutic agent in the treatment of mixed anxiety-depressive illness.
Cisplatin-induced acute liver and kidney injuries are serious problems in cancer patients during treatment of solid tumours.
This study sought to investigate possible protective effect of ethanolic fruit extract of Citrullus colocynthis (CC) against cisplatin-induced hepato-renal toxicity in rats.
Thirty male albino rats (150–200 g) were divided into five groups (n=6) and treated as follows: group 1: vehicle (10 mL/kg, p.o.; normal control); group 2: vehicle (10 mL/kg); groups 3–5: CC (100, 200 or 400 mg/kg, p.o.), respectively, for 10 days. Cisplatin (7.5 mg/kg; i.p.) was administered on the 7th day to animals in groups (2–5) 1 h after pretreatment. The animals were euthanized on day 10 for haematological, biochemical and histological analysis.
Cisplatin induced a significant increase in the serum levels of ALT, ALP, creatinine and blood urea nitrogen indicative of hepato-renal injury. More so, cisplatin caused marked increase in granulocyte, lymphocyte and platelets counts which were ameliorated by CC (100–400 mg/kg) treatment. In addition, cisplatin induced marked increase in MDA and nitrite levels coupled with deficits in glutathione, catalase and superoxide dismutase activities which were attenuated by CC administration. In vitro assay showed that CC scavenged DPPH and nitrite radicals (69.50 and 64.50 µg/mL, respectively). Total antioxidant capacity, phenolic and flavonoid contents are 24.27±0.09 mg QUE/g, 17.14±0.12 mg GAE/g and 10.20±0.09 mg QUE/g, respectively. CC preserved the liver and kidney histoarchitecture.
This study showed that C. colocynthis possesses hepatoprotective and nephroprotective actions possibly through enhancement of antioxidant defence system. Thus, it could be a potential adjuvant in cisplatin-based chemotherapy.
Background: The leaves of Antiaris toxicaria Lesch. (Moraceae) are used by traditional medicine practitioners in southwest Nigeria in the management of epilepsy, wounds, and neurological disorders. Hence, this study was undertaken to investigate the effect of the aqueous leaf extract of A. toxicaria on the central nervous system.
Methods: One hour after administration of A. toxicaria [50–300 mg/kg orally (p.o.)], its antidepressant effect was evaluated using the forced swimming test (FST), anxiolytic effect using elevated plus maze (EPM) test, and anticataleptic effect using haloperidol-induced catalepsy, whereas its effects on hypnosis and motor coordination were studied using hexobarbitone-induced sleeping time and open-field tests, respectively, in mice.
Results: Antiaris toxicaria (300 mg/kg) significantly increased swimming activity (36.88%) and reduced immobility time (38.54%). Pretreatment of mice with prazosin (an α1-adrenoceptor antagonist), sulpiride (a D2 receptor antagonist), and l-NG-nitro-arginine (nitric oxide synthase inhibitor) 15 min before A. toxicaria (300 mg/kg p.o.) treatment significantly prevented its antidepressant-like effect by 35.58%, 53.30%, and 56.11%, respectively, in the FST. However, pretreatment with metergoline (5-HT2 receptor antagonist), and atropine (muscarinic cholinergic antagonist) failed to reverse this effect. Interestingly, A. toxicaria (50 mg/kg) significantly increased open-arm exploration in the EPM by 70.31%, which was reversed by 82.66% in the presence of flumazenil [3 mg/kg intraperitoneally (i.p.)]. Haloperidol (1 mg/kg i.p.) induced cataleptic behavior in mice, which was reversed by A. toxicaria (300 mg/kg) (p<0.001) treatment.
Conclusions: The results suggest that A. toxicaria possesses an antidepressant-like effect involving interaction with α1-adrenoceptor, D2 dopamine receptor, and nitrergic pathway; an anxiolytic-like effect linked to the benzodiazepine system; and a neuroprotective effect.
Background:Adenia cissampeloides (Planch ex. Hook) Harms (Passifloraceae) leaf infusion is used in traditional African medicine as a stimulant to treat depression and insanity. Thus, this study investigates antidepressant and anxiolytic activities of the hydroethanol leaf extract of Adenia cissampeloides (ACE) in mice.
Methods: ACE (50–200 mg/kg, p.o.) was administered to mice 1 h before behavioral studies; the forced swimming test (FST), tail suspension test (TST), elevated-plus maze test (EPM) hole-board test (HBT) and open field test (OFT). In addition, the probable mechanisms of antidepressant- and anxiolytic-like actions of ACE were also investigated.
Results: ACE (100 and 200 mg/kg) produced significant (p<0.01) reduction in immobility, along with a significant increase in swimming activity (75.20%) and climbing (190.00%), respectively, similar to anti-immobility effect of imipramine in the FST. Also, in TST, ACE (100 and 200 mg/kg) treatment significantly (p<0.01) reduced the immobility time by 35.60%, and 35.27%, respectively, which was similar to anti-immobility effect of fluoxetine (32.50%). However, the antidepressant-like effect produced by ACE was prevented (p<0.01) by yohimbine (α2-adrenoceptor antagonist), or sulpiride (dopamine D2 receptor antagonist) pretreatment. ACE (50 and 100 mg/kg) treatment (p<0.01) increased number (41.67%) and duration of head-dips (52.27%) in HBT. Similarly, ACE (50–200 mg/kg) increased duration of open arm entries (p<0.001) in EPM. However, this effect was reversed (p<0.001) by pretreatment of mice with cyproheptadine (5-HT2 receptor antagonist) (60.87%).
Conclusions: Findings from these studies revealed antidepressant-like effect of ACE mediated through interaction with dopamine D2- receptor or α2-adrenoceptor. Also an anxiolytic-like effect through interaction with 5-HT2 receptors.
The brain’s cholinergic system occupies a central role in normal cognition and age-related cognitive decline, including Alzheimer’s disease (AD). This study sought to investigate the role of antioxidant defense and cholinergic systems on rutin-induced antiamnesia in mice.
Rutin (1, 5, or 50 mg/kg, p.o.) or vehicle (10 ml/kg, p.o.) was administered for three consecutive days. One hour post-treatment on day 3, scopolamine (3 mg/kg, i.p) was given, 5 min post-scopolamine injection, open field, Y-maze, or Morris water maze (MWM) (five days consecutive training sessions) tasks was carried out. The mice were sacrificed on day 7 to assays for biomarkers of oxidative stress and cholinergic system.
Scopolamine significantly reduced spontaneous alternation behavior in Y-maze and prolonged escape latency in MWM tasks when compared to vehicle-treated control indicative of working memory and spatial learning deficits. However, the pretreatment of mice with rutin (1, 5, or 50 mg/kg) prevented scopolamine-induced working memory and spatial learning impairments without affecting spontaneous locomotor activity. Scopolamine-induced nitrosative/oxidative stress and increased acetylcholinesterase activity in the prefrontal cortex and hippocampus were significantly attenuated by the pretreatment of mice with rutin.
rutin restored cognitive function in scopolamine-induced amnesia through enhancement of antioxidant defense and cholinergic systems.
Background:Annona muricata Linn. (Annonaceae) (AM) fruit juice is widely consumed either raw or after processing in tropical countries because of its very juicy, creamy and sweet character including its medicinal importance. The safety of AM fruit was investigated in Sprague-Dawley rats for acute and 60-day subchronic toxicity effects.
Methods: Rats were administered distilled water (DW) and AM daily at doses of 80, 400 and 2000 mg/kg orally for 60 days. At the end of the study, blood samples were assayed for biochemical and hematological parameters. Vital organs were harvested and assessed for antioxidants and histopathology.
Results: There was no mortality recorded up to 2000 mg/kg following acute administration. There were no significant changes in vital organ weights and hematological and biochemical parameters. However, significant (p<0.05) reduction in platelet count and packed cell volume was observed at 2000 and 400 mg/kg, respectively, which was reversed after cessation of treatment. Interestingly, subchronic oral administration of AM (80, 400 or 2000 mg/kg) significantly (p<0.001) increased sperm count and motility in comparison to vehicle-treated control. AM long-term treatment induced significant (p<0.05, <0.01 and <0.001) increases in the levels of glutathione, superoxide dismutase (SOD) and catalase, respectively, in the liver and kidney. Conversely, AM (2000 mg/kg) produced significant (p<0.001) increase in malondialdehyde level with decreased (p<0.05) SOD activity in the brain.
Conclusions: The study established that AM did not induce any significant toxic effect, indicating that it is safe in rats following oral administration for 60 consecutive days.
Background: Strophanthus hispidus DC (Apocynaceae) is a medicinal plant widely used in traditional African medicine in the treatment of rheumatic afflictions, ulcer, conjunctivitis, leprosy and skin diseases. This study sought to investigate the antinociceptive, anti-inflammatory and antiulcer properties of the ethanol root extract of S. hispidus.
Methods: Antinociceptive activity was evaluated using acetic acid-induced writhing and formalin tests in mice. The carrageenan- and egg albumin-induced rat paw edema tests were used to investigate the anti-inflammatory actions, whereas the antiulcer activity was investigated using ethanol-, HCl- and pyloric ligation-induced gastric ulcer models in rats.
Results: S. hispidus [100–800 mg/kg orally (po)] produced significant (p<0.05) inhibition of writhing reflex with peak effect of 74.13% inhibition observed at 800 mg/kg. Similarly, S. hispidus significantly (p<0.05) attenuated formalin-induced early and late phase of nociception with peak effect of 61.84% and 89.43%, respectively, at 200 mg/kg. S. hispidus (25–800 mg/kg po) caused significant (p<0.05) inhibition of edema development in the carrageenan and egg albumin models with peak effect (93.40% and 90.10% inhibition of edema formation) observed at 50 mg/kg. With respect to antiulcer activity, S. hispidus (100–800 mg/kg) showed potent antiulcer activity with respective peak effects of 96% (ethanol-induced), 99% (HCl-induced) and 70.60% inhibition of ulcer.
Conclusions: The findings in this study suggest that the ethanol root extract of S. hispidus possesses antinociceptive, anti-inflammatory and antiulcerogenic activities. This justifies the use of the extract in folklore medicine for the treatment of ulcer and inflammatory disorders.