Antidepressant and Anxiolytic Effects and Subacute Toxicity of the Aerial Parts of Psychotria ankasensis J.B.Hall (Rubiaceae) in Murine Models.

BACKGROUND: The present study aimed at validating the traditional use and toxicity profile of a methanolic extract of the aerial parts of Psychotria ankasensis in alleviating depression and anxiety disorders. METHOD: The antidepressant effect of methanolic extract of Psychotria ankasensis (PAE 30, 100, and 300 mg/kg, p.o.) was assessed in mice using the forced swim test (FST) and the tail suspension test (TST). The plant's anxiolytic potential was also evaluated in mice using the elevated plus-maze (EPM) and the open field tests (OFT). The subacute toxicity was assessed via oral administration of PAE at doses of 100, 300, and 1000 mg/kg in rats for 28 days. RESULTS: PAE 100 and 300 mg/kg showed antidepressant-like properties by significantly (at least p < 0.05) decreasing the frequency and duration of immobility in FST and TST. PAE (100 and 300 mg/kg) also showed a significant (at least p < 0.05) anxiolytic effect in both EPM and OFT. In the EPM test, E max for PAE and diazepam were 92.52 ± 40.11% and 85.95 ± 45.92%, respectively, whereas E max was approximately 100% for both test drugs in the OFT. Subacute administration of PAE did not reveal any toxic effects with respect to organ weight index, haematological, serum biochemical, and histopathological parameters. CONCLUSIONS: Methanolic extract of P. ankasensis exhibited antidepressant-like and anxiolytic-like effects devoid of significant toxicity at the doses tested in murine models.

Alkaloidal extract from Zanthoxylum zanthoxyloides stimulates insulin secretion in normoglycemic and nicotinamide/streptozotocin-induced diabetic rats.

INTRODUCTION: Increase in the prevalence of type-2 diabetes in Sub-Sahara Africa has created the need for robust treatment and management programs. However, an effective diabetes management program requires a high annual budget that most countries in this region cannot afford. That said, various plants and plant products in this region have either been confirmed and/or ethnopharmacologically used for the management of type-2 diabetes. AIM: To investigate the antidiabetic and insulin secretory effects of an alkaloidal extract derived from Zanthoxylum zanthoxyloides in normoglycemic and experimental diabetic rats. MATERIALS AND METHODS: Alkaloidal extract was prepared from leaves of Z anthoxylum zanthoxyloides (ZZAE). Nicotinamide/streptozotocin-induced type-2 diabetes was modeled in male Sprague Dawley rats weighing between 130 to 150 g. The experimental diabetic rats were grouped into six treatment groups [Model, 20% Tween20, chlorpropamide, and ZZAE (50, 100, and 150 mg/kg)], and one control group. Fasting blood glucose (FBG), and body weight were measured weekly. Rats were sacrificed 2 days after treatment under chloroform anesthesia to collect blood samples and to isolate major organs for biochemical, and histological analyses respectively. Islets of Langerhans were isolated from normoglycemic rats and co-cultured with ZZAE and chlorpropamide (10 µg/mL) to assess the insulin secretory effect of ZZAE. RESULTS: ZZAE improved glucose kinetics curve in normoglycemic (p < 0.001) and experimental diabetic rats (p < 0.05) compared to the model. ZZAE (100 and 150 mg/kg) restored islets population, and improved kidney, and liver, histoarchitecture. ZZAE (150 mg/kg) improved post-treatment serum insulin levels compared to the model group (p < 0.001) and the Chlorpropamide group (p < 0.05). ZZAE also restored glycogen synthesis in skeletal muscles of experimental diabetic rats and stimulated insulin secretion in pancreatic islets of Langerhans isolated from normoglycemic rats. CONCLUSION: These results showed that ZZAE has active alkaloids that can be explored for diabetes management.

Allanblackia floribunda Seed Extract Attenuates the Ethanol-Induced Gastric Ulcer in Rats via the Inhibition of TNF-α and INF-γ Levels and Modulation in the Expression of Ki67 Protein.

Allanblackia floribunda has been used to treat an upset stomach in African traditional medicine, but its efficacy and safety have not been scientifically studied. The present research is aimed at assessing the antiulcer property of the seed extract of the plant to validate its traditional claim. Rats were pretreated with three doses of aqueous extract of A. floribunda (AFE) at 30, 100, and 300 mg/kg or omeprazole 10 mg/kg for 1 hr before the acute gastric ulcer was induced by oral administration of 5 mL/kg of 98% ethanol. The animals were sacrificed under anesthesia, and the stomach and blood were collected. The gross histology of the stomach, percentage protection conferred by the treatment, gastric pH, and serum TNF-α and INF-γ were assessed as well as the expression of Ki67 antigens. The antioxidant properties as well as the acute toxicity profile of the plant extract were also assessed. The results show that A. floribunda conferred significant protection on the rats against gastric ulceration with % protection of 46.15, 57.69, and 65.38 for AFE 30, 100, and 300 mg/kg, respectively, as well as 69.23% for omeprazole 10 mg/kg. The plant extract caused marked reductions in gastric pH, TNF-α, and INF-γ with statistical significance (p < 0.001) for AFE 300 mg/kg and omeprazole 10 mg/kg. Also, the plant showed good antioxidant activity comparable to gallic acid. Furthermore, the plant extract modulated the expression of Ki67 antigens. All animals survived the 14-day delayed toxicity test with no significant differences in physical, hematological, and biochemical parameters between rats orally administered with supratherapeutic doses of AFE (5000 mg/kg) or normal saline. The study established that the gastroprotective effect of the seed extract of A. floribunda is attributable to its antisecretory, antioxidant, and anti-inflammatory properties. Additionally, the plant was found to promote ulcer healing via the modulation of the expression Ki67 and was safe at supratherapeutic doses.

Anti-inflammatory, anti-nociceptive and antipyretic activity of young and old leaves of Vernonia amygdalina.

BACKGROUND: Both young and old leaves of Vernonia amygdalina (VA) are traditionally used to treat inflammation, pain and fever. However, the efficacy of young and old leaves for treating these ailments have not been compared till date. AIM: To ascertain the effect of young and old leaves of VA in managing inflammation, pain and fever. METHODS: Both quantitative and qualitative phytochemical screening of ethanol extracts of young (EthYL) and old (EthOL) leaves of VA were performed. The anti-inflammatory activity of orally administered EthYL and EthOL (50-200 mg/kg) and Diclofenac (10 mg/kg) were evaluated in carrageenan-induced inflammation model in rats. Antipyretic activity of EthYL, EthOL and Aspirin (25 mg/kg) were assessed in the Baker's yeast-induced pyrexia model. Anti-allodynic effect of both extracts were evaluated by inserting inflamed paws of rats in cold water. Antinociceptive property of the extracts were assessed using tail withdrawal and formalin-induced nociception test. Histopathological examination of the paws was performed, in addition to formalin test to understand the possible mechanism of action of the extracts. Negative control rats received 2 ml/kg normal saline in all tests. RESULTS: The amount of flavonoids, alkaloids, tannins, and phenolics were significantly (p < 0.05) higher in EthOL than EthYL, while saponins were significantly higher (p < 0.05) in EthYL than EthOL. The antioxidant ability and total antioxidant capacity were significantly (p < 0.05) higher in EthYL than EthOL. However, this was significantly (p < 0.05) lower than the anti-oxidant activity of Ascorbic acid. A dose-dependent increase in anti-inflammatory, antipyretic and antinociceptive properties were observed in both EthYL and EthOL, similar to the standard drugs. Mast cell degranulation accompanied by vasodilatation and high leukocytosis were observed in the negative control, but were markedly low in extract treated groups. Both extracts mediated their analgesic effect through opioidergic and nitric oxide pathways with EthYL additionally implicating the muscarinic cholinergic system. CONCLUSION: Although both EthYL and EthOL alleviate inflammation, pyrexia and nociception, EthYL of VA was found to be more potent than EthOL.