Inhibition of α-amylase and α-glucosidase activities by ethanolic extract of Amaranthus cruentus leaf as affected by blanching.

This study investigated the inhibitory effect of Amaranthus cruentus 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 the vegetable on these key enzymes. Fresh leaves of A. cruentus were blanched in hot water for 10 min, and the ethanolic extracts of both the fresh and blanched vegetables were prepared and used for subsequent analysis. The inhibitory effect of the extract on α-amylase and α-glucosidase activities as well as some antioxidant parameter was determined in vitro. The result revealed that extract of unprocessed A. cruentus leaf reduce Fe3+ to Fe2+ and also inhibited α-amylase and α-glucosidase activities in a dose dependent manner. However, blanching of the leafy vegetables caused a significant (P < 0.05) increase in the antioxidant properties but decreased their ability to inhibit α-amylase and α-glucosidase activities. This antioxidant properties and enzyme inhibition could be part of the mechanism by which they are used in the treatment/prevention of type-2 diabetes. However, the blanched vegetable reduced their ability to inhibit both α-amylase and α-glucosidase activity in vitro

Biological Activities of Essential Oils: From Plant Chemoecology to Traditional Healing Systems

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

Local condiments from fermented tropical legume seeds modulate activities of critical enzymes relevant to cardiovascular diseases and endothelial function

Investigation into modulatory effects of local condiments produced from fermented legume (African locust bean and soybean) seeds on activities of enzymes relevant to endothelial function and cardiovascular disease (arginase, phosphodiesterase‐5, acetylcholinesterase, and, ecto 5′‐nucleotidase) in vitro was the focus of this study. The condiments were prepared according to traditional methods of fermentation. Thereafter, modulatory effects of aqueous extracts from the condiments on activities of the enzymes were subsequently carried out. Results showed the extracts significantly inhibited activities of arginase, phosphodiesterase‐5 and acetylcholinesterase, while the activity of ecto 5′‐nucleotidase was stimulated at sample concentrations tested. Thus, the observed enzyme modulatory properties exhibited by the condiments could be novel mechanisms to support their use as functional foods and nutraceuticals for the management of cardiovascular disease and associated endothelial dysfunction

Drying alters the phenolic constituents, antioxidant properties, α‐amylase, and α‐glucosidase inhibitory properties of Moringa (Moringa oleifera ) leaf

Moringa oleifera leaf is a popular green leafy vegetable which has found its usefulness in the preparation of traditional stews and soups. Like most green leafy vegetable which are not around year‐round, the leaf is usually dried and pulverized for storage and easier handling, and despite the popularity of this processing technique, there is dearth of information on how drying affects the health‐promoting properties of the leaves. Hence, this study sought to investigate the effect of some drying methods (freeze‐drying, sun, air and oven drying) on the phytoconstituents, antioxidant properties, and biological activities of moringa leaf. This study revealed that drying methods significantly altered the phytoconstituents (phenolics, flavonoids, vitamin C, tannin, saponin, phytate, oxalate, alkaloid, cardenolides, and cardiac glycosides), antioxidant capacities (reducing power, Fe2+chelating, ABTS •+, DPPH , and •OH scavenging abilities), and enzyme inhibitory (α‐amylase and α‐glucosidase) effects of the leaf, with freeze‐drying being the most promising method for preserving the nutraceutical properties of moringa leaf. However, for practical application, the order of preference of the drying methods which ensures adequate retention of phytoconstituents and possibly biological activities of the leaf as observed in this study is freeze‐drying &gt; air drying &gt; sun drying &gt; oven drying, in the order of decreasing magnitude

Consumption of thermally oxidized palm oil diets alters biochemical indices in rats

Palm oil is thermally oxidized to increase its palatability and this has been a usual practice in most homes. This study sought to assess the biochemical responses of rats to thermally oxidized palm oil diets. Therefore, Wistar strain albino rats (Rattus norveigicus) were fed with fresh palm oil (control) and thermally oxidized palm oil (test groups) diets and water ad libitum for 30 days. Then, the malondialdehyde (MDA) contents and total protein of the plasma and liver were determined. Subsequently, the plasma liver function markers [alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), albumin (ALB) and total bilirubin (TBIL) ] and the lipid profile [triglyceride (TRIG), total cholesterol (T-CHOL), high density lipoprotein (HDL-CHOL) and low density lipoprotein (LDL-CHOL) ] were assayed. The results of the study revealed that there was a significant decrease (P < 0.05) in the plasma and liver total protein, ALB, TRIG and HDL-CHOL of the test groups when compared with the control. Conversely, there was a significant increase (P < 0.05) in the activities of ALT, AST and ALP, TBIL, T-CHOL, LDL-CHOL and plasma/liver MDA of the test groups when compared with the control. These effects were most pronounced in rats fed with 20 min-thermally oxidized palm oil diet. Hence, consumption of thermally oxidized palm oil diets had deleterious effects on biochemical indices in rats. Therefore, cooking with and/or consumption of palm oil subjected to heat treatment for several long periods of time should be discouraged in our homes as this might have deleterious effects on human health

Drying Methods Alter Angiotensin-I Converting Enzyme Inhibitory Activity, Antioxidant Properties, and Phenolic Constituents of African Mistletoe ( L) Leaves

This study investigated the most appropriate drying method (sun drying, oven drying, or air drying) for mistletoe leaves obtained from almond tree. The phenolic constituents were characterized using high-performance liquid chromatography–diode array detector, while the inhibitory effect of the aqueous extracts of the leaves on angiotensin-I converting enzyme (ACE) was determined in vitro as also the antioxidant properties. Oven-dried extract (kidney [276.09 μg/mL] and lungs [303.41 μg/mL]) had the highest inhibitory effect on ACE, while air-dried mistletoe extract (kidney [304.47 μg/mL] and lungs [438.72 μg/mL]) had the least. Furthermore, the extracts dose-dependently inhibited Fe 2+ and sodium nitroprusside-induced lipid peroxidation in rat’s heart and kidney. Also, all extracts exhibited antioxidative properties as typified by their radical scavenging and Fe-chelating ability. Findings from this study revealed that oven drying is the best of the 3 drying methods used for mistletoe obtained from almond host tree, thus confirming that diversity in drying methods leads to variation in phenolic constituents and biological activity of plants

Modulation of some markers of erectile dysfunction and malonaldehyde levels in isolated rat penile tissue with unripe and ripe plantain peels: identification of the constituents of the plants using HPLC

Context: Plantain fruit pulp has been used as a natural remedy to manage erectile dysfunction (ED) in traditional medicine. However, the potency of the peel has not been examined with respect to ED management. Objective: This study investigated and compared the inhibitory potential of unripe (UPP) and ripe (RPP) plantain peels on some enzymes associated with ED and Fe2+-induced oxidative stress in albino rat penile homogenate in vitro. Materials and method: Aqueous extract of the peels was prepared and the effect on phosphodiesterase-5 (PDE-5), arginase, acetylcholinesterase (AChE), angiotensin-I converting enzyme (ACE) and Fe2+-induced malonyladehyde in isolated albino rat penile homogenate were investigated. Phenolic constituents of the peels powder were characterized using high-performance liquid chromatography coupled with diode array detector (HPLC-DAD). Result: Extract from UPP had higher PDE-5 (IC50 = 3.10 μg/mL), arginase (IC50 = 0.96 μg/mL), AChE (IC50 = 6.30 μg/mL) and ACE (IC50 = 0.41 μg/mL) inhibitory ability compared with RPP (PDE-5, IC50 = 4.33 μg/mL; arginase, IC50 = 1.34 μg/mL; AChE, IC50 = 8.64 μg/mL; ACE, IC50 = 0.63 μg/mL). The extract from UPP also had higher inhibition of Fe2+-induced lipid peroxidation. HPLC-DAD analysis revealed that gallic and caffeic acids, rutin, quercitrin and quercetin were abundant in UPP, while catechin, kaempferol, chlorogenic and ellagic acids were the dominant phenolic compounds in RPP. Discussion and conclusion: Inhibition of enzymes associated with ED and lipid peroxidation could be linked with the phenolic compounds. However, UPP appeared to be more potent

Antiulcer Agents: From Plant Extracts to Phytochemicals in Healing Promotion

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

Phytochemicals in Helicobacter pylori Infections: What Are We Doing Now?

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