Ayodeji Oyenihi

Copyright © 2015 Ayodeji Babatunde Oyenihi et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Chronic hyperglycaemia (an abnormally high glucose concentration in the blood) resulting fromdefects in insulin secretion/action, or both, is the major hallmark of diabetes in which it is known to be involved in the progression of the condition to different complications that include diabetic neuropathy. Diabetic neuropathy (diabetes-induced nerve damage) is the most common diabetic complication and can be devastating because it can lead to disability. There is an increasing body of evidence associating diabetic neuropathy with oxidative stress. Oxidative stress results from the production of oxygen free radicals in the body in excess of its ability to eliminate them by antioxidant activity. Antioxidants have different mec...

Redox mechanisms are central themes in the progression of diabetes—a chronic disorder with an increasing global prevalence rate. Uncontrolled hyperglycemia ensures the overactivation of oxidative stress cascades that promote the development of life-limiting diabetic complications. Novel therapeutic agents with the ability to improve antioxidant status in patients, in addition to other antidiabetic actions, may offer superior efficacy. Regarding this, natural products and medicinal plants have been postulated to be an underexplored source of such agents. Centella asiatica (CA) has been used in the traditional medicine systems of Asian and African countries for the management of several ailments including diabetes and is now commercially available as a dietary supplement. Here, scientific evidence supporting the antioxidant and antidiabetic potentials of CA are integrated to fully harness its clinical utility. Furthermore, the importance of CA extract standardization and the urgent ne...

The encapsulation of bioactive-rich plant extracts is an effective method of preventing their damage or loss of activity during processing and storage. Here, the techno-functional properties of microcapsules developed from Moringa oleifera leaf powder (MoLP) extract (core) with maltodextrin (MD), gum Arabic (GA), and a combination (MDGA) (coatings) were assessed. The bulk and tap density were 0.177, 0.325 and 0.297 g/mL and 0.13, 0.295 and 0.259 g/mL for GA, MD and MDGA microcapsules, respectively. Flowability properties of microcapsules indicated an intermediate flow except for GA which had a poor flow. The moisture content of the microcapsules ranged from 1.47% to 1.77% with no significant differences (p > 0.05) observed. All the microcapsules had high water solubility (86.35% for GA to 98.74% for MD and 90.51% for MDGA). Thermogravimetric analyses revealed that encapsulation enhanced the thermal stability of the core material. The X-ray diffraction analysis revealed that the m...

This study investigated the protective properties of strawberry fruit on testicular oxidative injury. Oxidative injury was induced in vitro in testicular tissue homogenates by incubation with ferrous sulphate (FeSO4) in the presence and absence of strawberry fruit extract (SFE) for 30 min at 37˚C, with gallic acid serving as the standard antioxidant drug. Induction of oxidative injury significantly reduced glutathione, cholesterol and triglyceride levels; and inhibited SOD, catalase and ENTPDase activities when compared to normal control. It also led to exacerbated nitric oxide, malondialdehyde, LDL‐cholesterol levels, acetylcholinesterase, ATPase and lipase activities. These effects were, however, reversed following treatment with SFE when compared to the untreated control, except for cholesterol and triglyceride levels. Additionally, the induction of the oxidative injury led to alterations in testicular lipid metabolites that were accompanied by the activation of α‐linolenic acid ...

Health benefits have been attributed to the consumption of watermelon (Citrullus lanatus L.) seeds in sub-Saharan Africa and Asia but the potential toxicity especially on chronic use remains to be investigated. Here, diets containing watermelon seeds (WMSs) at 2.5% or 5% were eaten ad libitum daily for 21 d by male and female Wistar rats. Changes in body and organ (liver, kidney, brain, testis, and ovary) weights following diet supplementation were monitored. Biomarkers of organ injury, such as alanine aminotransferase (ALT), alkaline phosphatase (ALP), cholesterol (CHO), triglyceride (TRI), urea, and creatinine (CRE) were measured. WMS-formulated diet led to a decrease in body weight in male but not in female rats compared to the control group. Also, testes weight significantly increased, whereas a decrease in that of the ovaries was noted. Although the ingestion of WMS did not significantly alter the weights of the liver and brain, a trend toward reduction was noticed. No signific...

The in vivo effects of Centella asiatica L. Urban (Family: Apiaceae; CA) on diabetes‐induced testicular fatty acid misdistribution and oxidative injury were investigated. Diabetic rats were treated with vehicle, CA or metformin daily for 14 days by oral gavage. Fatty acid (FA) content in testis was analysed using gas chromatography‐flame ionisation detection while redox indices were measured as peroxide value (PV), malondialdehyde (MDA), oxygen radical antioxidant capacity (ORAC), reduced glutathione (GSH), glutathione S‐transferase (GST) and glutathione peroxidase (GPx) activities. Diabetes increased omega‐6 (61%), and decreased omega‐3 (23%) and monounsaturated fatty acids (MUFA; 18%) compared to non‐diabetic controls. Oxidative injury in diabetic rats was confirmed by increases in PV (112%) and MDA (77%) in addition to decreases in GSH (41%) and activities of GST (19%) & GPx (24%) compared to non‐diabetic controls. CA treatment led to 17% reduction in omega‐6 and 33% rise in MUFA...

Metabolite profiling of cancer cells presents many opportunities for anticancer drug discovery. The Chinese, Indian, and African flora, in particular, offers a diverse source of anticancer therapeutics as documented in traditional folklores. In-depth scientific information relating to mechanisms of action, quality control, and safety profile will promote their extensive usage in cancer therapy. Metabolomics may be a more holistic strategy to gain valuable insights into the anticancer mechanisms of action of plants but this has remained largely unexplored. This review, therefore, presents the available metabolomics studies on the anticancer effects of herbal medicines commonly used in Africa and Asia. In addition, we present some scientifically understudied ‘candidate plants’ for cancer metabolomics studies and highlight the relevance of metabolomics in addressing other challenges facing the drug development of anticancer herbs. Finally, we discussed the challenges of using metabolom...

Context: Neutralizing the over-activation of oxidative stress and inflammation remains an important goal
in the management of type 2 diabetes mellitus (T2DM). Centella asiatica (L.) Urban (Apiaceae) (CA) has
been used in traditional folklore in Africa and Asia to treat various ailments including diabetes.
Objective: We investigated the hepatic antioxidant and anti-inflammatory potential of methanol extract
of CA leaves in T2DM.
Materials and methods: T2DM was induced in male Sprague-Dawley rats with 10% fructose in drinking
water for 14 days followed by a single intraperitoneal injection of streptozotocin (40mg/kg b.wt). Hepatic
oxidant/antioxidant status was assessed by measuring the concentrations of malondialdehyde (MDA), ferric
reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), Trolox equivalent antioxidant
capacity (TEAC), reduced glutathione (GSH) and activities of glutathione S-transferase (GST) and
glutathione peroxidase (GPX). The concentrations of cytokines IL-1b, IL-4, IL-6, IL-10, MCP-1 and TNF-a in
the liver were determined.
Results: Diabetes increased MDA formed (47%) and reduced FRAP (20%), TEAC (15%), GSH levels (32%),
significantly; decreased GST and GPX activities in the liver and elevated levels of cytokines studied.
Treatment of diabetic rats with 500 mg/kg b.wt CA for 14 days decreased MDA (44%); elevated FRAP
(15%) and GSH (131%) levels and increased the activities of GST and GPX by 16%. Hepatic concentrations
of IL-1b, MCP-1 and TNF-a in DCA group were reduced to 68%, 75% and 63% of DC values, respectively.
Conclusions: The antioxidant and anti-inflammatory properties of CA may protect tissues such as the liver
from diabetes-induced oxidative damage.

Despite recent advances in the understanding and management of diabetes mellitus, the prevalence of the disease is increasing unabatedly with resulting disabling and life-reducing consequences to the global human population. The limitations and side effects associated with current antidiabetic therapies have necessitated the search for novel therapeutic agents. Due to the multipathogenicity of diabetes mellitus, plant-derived compounds with proven multiple pharmacological actions have been postulated to " hold the key " in the search for an affordable, efficacious, and safer therapeutic agent in the treatment of the disease and associated complications. Resveratrol, a phytoalexin present in few plant species, has demonstrated beneficial antidiabetic effects in animals and humans through diverse mechanisms and multiple molecular targets. However, despite the enthusiasm and widespread successes achieved with the use of resveratrol in animal models of diabetes mellitus, there are extremely limited clinical data to confirm the antidiabetic qualities of resveratrol. This review presents an update on the mechanisms of action and protection of resveratrol in diabetes mellitus, highlights challenges in its clinical utility, and suggests the way forward in translating the promising preclinical data to a possible antidiabetic drug in the near future.

Chronic and acute alcohol exposure has been extensively reported to cause oxidative stress in hep-atic and extra-hepatic tissues. Watermelon (Citrullus lanatus) is known to possess various beneficial properties including; antioxidant, anti-inflammatory, analgesic, anti-diabetic, anti-ulcerogenic effects. However, there is a lack of pertinent information on its importance in acute alcohol-induced hepato-and neuro-toxicity. The present study evaluated the potential protective effects of watermelon juice on ethanol-induced oxidative stress in the liver and brain of male Wistar rats. Rats were pre-treated with the watermelon juice at a dose of 4 ml/kg body weight for a period of fifteen days prior to a single dose of ethanol (50%; 12 ml/kg body weight). Ethanol treatment reduced body weight gain and significantly altered antioxidant status in the liver and brain. This is evidenced by the significant elevation of malondi-aldehyde (MDA) concentration; depletion in reduced glutathione (GSH) levels and an increased catalase (CAT) activity in the brain and liver. There was no significant difference in the activity of glutathione peroxidase (GPX) in the liver and brain. Oral administration of watermelon juice for fifteen (15) days prior to ethanol intoxication, significantly reduced the concentration of MDA in the liver and brain of rats. In addition, water melon pre-treatment increased the concentration of GSH and normalized catalase activity in both tissues in comparison to the ethanol control group. Phytochemical analysis revealed the presence of phenol, alkaloids, saponins, tannins and steroids in watermelon juice. Our findings indicate that watermelon juice demonstrate anti-oxidative effects in ethanol-induced oxidation in the liver and brain of rats; which could be associated with the plethora of antioxidant phyto-constituents present therein .

Chronic hyperglycaemia (an abnormally high glucose concentration in the blood) resulting from defects in insulin secretion/action, or both, is the major hallmark of diabetes in which it is known to be involved in the progression of the condition to different complications that include diabetic neuropathy. Diabetic neuropathy (diabetes-induced nerve damage) is the most common diabetic complication and can be devastating because it can lead to disability. There is an increasing body of evidence associating diabetic neuropathy with oxidative stress. Oxidative stress results from the production of oxygen free radicals in the body in excess of its ability to eliminate them by antioxidant activity. Antioxidants have different mechanisms and sites of actions by which they exert their biochemical effects and ameliorate nerve dysfunction in diabetes by acting directly against oxidative damage. This review will examine different strategies for managing diabetic neuropathy which rely on exogenous antioxidants.

Ethnopharmacological relevance: Garcinia kola seed is commonly used in African Traditional Medicine as a remedy for liver disorders, hepatitis, bronchitis, throat infections as well as an aphrodisiac and fertility enhancing substance. Owing to the abundance of complex mixture of phenolic compounds in Garcinia kola seed, there is a growing safety concern on its long-term use in folklore medicine. The present study evaluated the hepatic, testicular and spermatozoa antioxidant status in rats chronically treated with Garcinia kola seed. Materials and methods: Adult male Wistar rats were randomly assigned to four groups of 10 rats each and were orally administered with Garcinia kola at 0, 250, 500 and 1000 mg/kg for 6 consecutive weeks. Clinical observations, serum biochemistry, oxidative stress biomarkers, spermatozoa parameters and histopathological examination of the organs were assessed to monitor treatment-related adverse effects in rats. Results: Long-term treatment of Garcinia kola had no adverse effect on the spermatozoa characteristics but significantly elevated testosterone concentration when compared to the control group. Improvement of antioxidant systems was accompanied by a significant decrease in malondialdehyde level in the liver, testes and spermatozoa of Garcinia kola-treated rats. Histological observation revealed that chronic administration of Garcinia kola had no effect on the liver and testes at all doses when compared with control. Conclusion: Garcinia kola seed boosts the antioxidant status and exhibits no adverse effect on the liver, testes and spermatozoa after a long-term oral exposure in rats.

Introduction
Diabetes mellitus (DM) is one of the most common metabolic disorders worldwide with an
estimated 143 million people suffering from the disease [1]. This number may double by 2030
[2]. Although understanding of the pathophysiological processes involved in DM has increased,
with great feats achieved in the management of DM, yet serious diabetic complications
still confront patients and physicians [3]. Diabetes mellitus is characterized by chronic
hyperglycemia (very high blood glucose levels) and disturbances of carbohydrate, fat and
protein metabolism associated with absolute or relative deficiency in insulin secretion or
insulin action [4-5]. On the basis of aetiology and clinical presentation, DM is classified into
two; type 1 diabetes mellitus also called insulin-dependent diabetes mellitus (IDDM) and type
2 which is the non-insulin dependent diabetes mellitus (NIDDM). The effects of DM include
long term damage, dysfunction and failure of various organs, especially the eyes, kidneys,
livers, hearts, and blood vessels [6].In the treatment of diabetes, many oral hypoglycemic agents like sulfonylureas, meglitinides,
thiazolidines, D-phenylalanine and α-glucosidase inhibitors are used in addition to insulin
treatment action along with appropriate diet and exercise [5]. However, none can be termed
as an ideal one, due to their toxic side effects and sometimes diminution in response after
prolonged use [7]. The limitations and side effects associated with existing synthetic oral
hypoglycemic agents had necessitated the search for newer drugs. As a result, natural agents
from plants and plant products have been the alternative target to source for new antioxidant
and antidiabetic agents based on their traditional use.