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Tropical vegetables remain one of the major sources of functional foods and nutraceuticals, while their constituent phytochemicals, especially alkaloids, have been reported to exhibit neuroprotective properties. Here, the protective effect of alkaloid extracts from Scent leaf (Ocimum gratissimum) and Water bitter leaf (Struchium sparganophora) on manganese (Mn)- induced toxicity in wild type fruit fly (Drosophila melanogaster) model was investigated. Flies were exposed to 30 mM of Mn, the alkaloid extracts (20 and 200 µg/g) and co-treatment of Mn plus extracts, respectively. The survival rate and locomotor performance of the flies were assessed 7 days post-treatment, after which the flies were homogenized and assayed for activities of acetylcholinesterase (AChE), monoamine oxidase (MAO), glutathione-S transferase (GST), catalase, superoxide dismutase SOD), as well as total thiol, reactive oxygen species (ROS) and neural L-DOPA levels. Results showed that the extract significantly reversed Mn-induced reduction in the survival rate and locomotor performance of the flies. Furthermore, both extracts counteracted the Mn-induced elevation in AChE and MAO activities, as well as reduced antioxidant enzyme activities, with a concomitant mitigation of Mn-induced elevated ROS and neural L-DOPA level. The HPLC characterization of the extracts revealed the presence of N-propylamine, Vernomine and Piperidine as predominant in Water bitter leaf extract, while 2, 6-dimethylpyrazine and sesbanimide were found in scent leaf extract. Therefore, the alkaloid extract of these leaves may thus be sources of useful nutraceuticals for the management of pathological conditions associated with manganese toxicity. [ABSTRACT FROM AUTHOR]

Essential oils are complex mixtures of hydrocarbons and their oxygenated derivatives arising from two different isoprenoid pathways. Essential oils are produced by glandular trichomes and other secretory structures, specialized secretory tissues mainly diffused onto the surface of plant organs, particularly flowers and leaves, thus exerting a pivotal ecological role in plant. In addition, essential oils have been used, since ancient times, in many different traditional healing systems all over the world, because of their biological activities. Many preclinical studies have documented antimicrobial, antioxidant, anti-inflammatory and anticancer activities of essential oils in a number of cell and animal models, also elucidating their mechanism of action and pharmacological targets, though the paucity of in human studies limits the potential of essential oils as effective and safe phytotherapeutic agents. More well-designed clinical trials are needed in order to ascertain the real efficacy and safety of these plant products. [ABSTRACT FROM AUTHOR]

In this critical review, plant sources used as effective antibacterial agents against Helicobacter pylori infections are carefully described. The main intrinsic bioactive molecules, responsible for the observed effects are also underlined and their corresponding modes of action specifically highlighted. In addition to traditional uses as herbal remedies, in vitro and in vivo studies focusing on plant extracts and isolated bioactive compounds with anti-H. pylori activity are also critically discussed. Lastly, special attention was also given to plant extracts with urease inhibitory effects, with emphasis on involved modes of action. [ABSTRACT FROM AUTHOR]

In this narrative review, we have comprehensively reviewed the plant sources used as antiulcer agents. From traditional uses as herbal remedies, we have moved on to preclinical evidence, critically discussing the in vitro and in vivo studies focusing on plant extracts and even isolated phytochemicals with antiulcerogenic potential. A particular emphasis was also paid to Helicobacter pylori activity, with emphasis on involved mechanisms of action. Lastly, the issue of safety profile of these plant products has also been addressed. [ABSTRACT FROM AUTHOR]

Management of the blood glucose level is a critical strategy in the control of diabetes complications. Inhibitors of saccharide hydrolysing enzymes have been useful as oral hypoglycemic drugs for the control of hyperglycemia especially in patients with type-2 diabetes mellitus. This study compares the phenolic contents and antioxidant properties of two varieties of ginger, namely, Red (Zingiber officinale var. Rubra) and white (Zingiber officinale Roscoe), and their inhibitory effects on the activities of α-amylase and α-glucosidase (key enzymes linked to type-2 diabetes) using an in vitro model. The results show that the aqueous extracts of red ginger had significantly (P < 0.05) higher phenolic contents as well as higher antioxidant activities than the aqueous extracts of white ginger. However, contrary to the phenolic contents and antioxidant properties, white ginger had a significantly (P < 0.05) stronger inhibitory effect on α-amylase and α-glucosidase activities than red ginger. Furthermore, both extracts exhibited mild a-amylase and stronger α-glucosidase inhibitory activities, suggesting their potential use in dietary intervention in the management or control of postprandial hyperglycemia associated with type-2 diabetes. White ginger exhibited stronger enzyme inhibitory effects than red ginger. [ABSTRACT FROM AUTHOR]

Raphiodon echinus (R. echinus) is used in Brazilian folk medicine for the treatment of inflammation, coughs, and infectious diseases. However, no information is available on the potential antioxidant, cytotoxicity and genotoxicity of this plant. In this study, the polyphenolic constituents, antioxidant capacity and potential toxic effects of aqueous and ethanolic extracts of R. echinus on human erythrocytes and leukocytes were investigated for the first time. R. echinus extracts showed the presence of Gallic, chlorogenic, caffeic and ellagic acids, rutin, quercitrin and quercetin. Aqueous and ethanolic extracts of R. echinus exhibited antioxidant activity in DPPH radical scavenging with IC50 = 111.9 μg/mL (EtOH extract) and IC50 = 227.9 μg/mL (aqueous extract). The extracts inhibited Fe(2+) (10 μM) induced thiobarbituric acid reactive substances (TBARS) formation in rat brain and liver homogenates. The extracts (30-480 μg/mL) did not induce genotoxicity, cytotoxicity or osmotic fragility in human blood cells. The findings of this present study therefore suggest that the therapeutic effect of R. echinus may be, in part, related to its antioxidant potential. Nevertheless, further in vitro and in vivo studies are required to ascertain the safety margin of its use in folk medicine.

Recent studies have shown that vegetables consumption could lower the risk of diabetes mellitus. Therefore, this study sought to investigate the inhibitory effect of Struchium sparganophora (Ewuro Odo) leaf on key enzyme linked to type-2 diabetes (α-amylase and α-glucosidase) as well as assessing the effect of blanching (a commonly practiced food processing technique) of this leafy vegetable on these key enzymes. Fresh leaves of Struchium sparganophora were blanched in hot water for 10 minutes, and the 70% ethanolic extracts of the fresh and blanched vegetables were prepared and used for subsequent analysis. The antioxidant properties and interaction of the extracts on α - amylase and α - glucosidase activities was determined in vitro. The result revealed that Struchium sparganophora leaf scavenged DPPH free radical and also inhibited α -amylase and α - glucosidase activities in a dose dependent manner (0.05 -0.2 mg/ml). However, blanching of this leafy vegetables caused a significant (P<0.05) increase in the antioxidant properties as typified by the DPPH radical scavenging ability and reducing property but decrease their ability to inhibit α - amylase and α - glucosidase activities. This antioxidant properties and enzyme inhibition could be part of the mechanism by which green leafy vegetables exert their anti-diabetic properties. However, blanching of the vegetable could reduce their ability to inhibit both α - amylase and α - glucosidase activity, but enhance their antioxidant properties in vitro.