Antidiabetic Activity of Sargassum hystrix Extracts in Streptozotocin-Induced Diabetic Rats

The beneficial effects of ethanolic extract of Sargassum serratifolium in DNCB-induced mouse model of atopic dermatitis

Atopic dermatitis is a chronic complex inflammatory skin disorder that requires sustainable treatment methods due to the limited efficacy of conventional therapies. Sargassum serratifolium, an algal species with diverse bioactive substances, is investigated in this study for its potential benefits as a therapeutic agent for atopic dermatitis. RNA sequencing of LPS-stimulated macrophages treated with ethanolic extract of Sargassum serratifolium (ESS) revealed its ability to inhibit a broad range of inflammation-related signaling, which was proven in RAW 264.7 and HaCaT cells. In DNCB-induced BALB/c or HR-1 mice, ESS treatment improved symptoms of atopic dermatitis within the skin, along with histological improvements such as reduced epidermal thickness and infiltration of mast cells. ESS showed a tendency to improve serum IgE levels and inflammation-related cytokine changes, while also improving the mRNA expression levels of Chi3l3, Ccr1, and Fcεr1a genes in the skin. Additionally, ESS compounds (sargachromanol (SCM), sargaquinoic acid (SQA), and sargahydroquinoic acid (SHQA)) mitigated inflammatory responses in LPS-treated RAW264.7 macrophages. In summary, ESS has an anti-inflammatory effect and improves atopic dermatitis, ESS may be applied as a therapeutics for atopic dermatitis.

Algae Food Products as a Healthcare Solution

Diseases such as obesity; cardiovascular diseases such as high blood pressure, myocardial infarction and stroke; digestive diseases such as celiac disease; certain types of cancer and osteoporosis are related to food. On the other hand, as the world's population increases, the ability of the current food production system to produce food consistently is at risk. As a result, intensive agriculture has contributed to climate change and a major environmental impact. Research is, therefore, needed to find new sustainable food sources. One of the most promising sources of sustainable food raw materials is macroalgae. Algae are crucial to solving this nutritional deficiency because they are abundant in bioactive substances that have been shown to combat diseases such as hyperglycemia, diabetes, obesity, metabolic disorders, neurodegenerative diseases and cardiovascular diseases. Examples of these substances include polysaccharides such as alginate, fucoidan, agar and carrageenan; proteins such as phycobiliproteins; carotenoids such as β-carotene and fucoxanthin; phenolic compounds; vitamins and minerals. Seaweed is already considered a nutraceutical food since it has higher protein values than legumes and soy and is, therefore, becoming increasingly common. On the other hand, compounds such as polysaccharides extracted from seaweed are already used in the food industry as thickening agents and stabilizers to improve the quality of the final product and to extend its shelf life; they have also demonstrated antidiabetic effects. Among the other bioactive compounds present in macroalgae, phenolic compounds, pigments, carotenoids and fatty acids stand out due to their different bioactive properties, such as antidiabetics, antimicrobials and antioxidants, which are important in the treatment or control of diseases such as diabetes, cholesterol, hyperglycemia and cardiovascular diseases. That said, there have already been some studies in which macroalgae (red, green and brown) have been incorporated into certain foods, but studies on gluten-free products are still scarce, as only the potential use of macroalgae for this type of product is considered. Considering the aforementioned issues, this review aims to analyze how macroalgae can be incorporated into foods or used as a food supplement, as well as to describe the bioactive compounds they contain, which have beneficial properties for human health. In this way, the potential of macroalgae-based products in eminent diseases, such as celiac disease, or in more common diseases, such as diabetes and cholesterol complications, can be seen.

Antidiabetic, antihyperlipidemic and protective effects of Gladiolus psittacinus on hyperglycemia-mediated oxidative stress in streptozotocin-induced diabetic rats

OBJECTIVES

Gladiolus psittacinus (GP) is an important medicinal plant in folk medicine where its corm is used for treatment of diabetes mellitus. Despite this, there is paucity of scientific information to justify its use as antidiabetic drug. Hence, this study was designed to explore antidiabetic, antihyperlipidemic and effects of aqueous extract of Gladiolus psittacinus (AGP) on hyperglycemia-associated oxidative stress in pancreas, kidney and liver of diabetic rats.

METHODS

Diabetes mellitus (DM) was induced in rats using streptozotocin 50 mg/kg (i.p.). Normal and diabetic rats were treated orally with AGP once a day for 14 days. Antidiabetic effects were evaluated on body weight, fasting blood glucose concentration (FBGC), lipid profiles and serum chemistry. Also, protective effects of AGP were also determined on markers of oxidative stress, antioxidant enzymes and histopathology of pancreas, kidney and liver of diabetic rats.

RESULTS

Treatment with AGP emanated to significant decrease of FBGC (552.67-157.33 mg/dL), increase in body weight (100.01-133.76 g) and positive modulation of lipid parameters in diabetic rats. The alteration in the contents of markers of liver and kidney function were significantly modulated in the diabetic rats upon treatment. Also, oxidative damage and antioxidant depletions in pancreas, kidney and liver were significantly mitigated in treated diabetic rats. Structural aberrations in the histopathology slides of pancreas, kidney and liver were improved upon treatment.

CONCLUSIONS

It can be concluded that AGP could be used in the treatment of diabetes mellitus and its related ailments, thereby justifying its usage in traditional medicine.

Antioxidant and Antidiabetic Activity of Algae

Currently, algae arouse a growing interest in the pharmaceutical and cosmetic area due to the fact that they have a great diversity of bioactive compounds with the potential for pharmacological and nutraceutical applications. Due to lifestyle modifications brought on by rapid urbanization, diabetes mellitus, a metabolic illness, is the third largest cause of death globally. The hunt for an efficient natural-based antidiabetic therapy is crucial to battling diabetes and the associated consequences due to the unfavorable side effects of currently available antidiabetic medications. Finding the possible advantages of algae for the control of diabetes is crucial for the creation of natural drugs. Many of algae's metabolic processes produce bioactive secondary metabolites, which give algae their diverse chemical and biological features. Numerous studies have demonstrated the antioxidant and antidiabetic benefits of algae, mostly by blocking carbohydrate hydrolyzing enzyme activity, such as α-amylase and α-glucosidase. Additionally, bioactive components from algae can lessen diabetic symptoms in vivo. Therefore, the current review concentrates on the role of various secondary bioactive substances found naturally in algae and their potential as antioxidants and antidiabetic materials, as well as the urgent need to apply these substances in the pharmaceutical industry.

Potential effect of Turbinaria decurrens acetone extract on the biochemical and histological parameters of alloxan-induced diabetic rats

Upon Seeking natural and safe alternatives for synthetic medicines to treat many chronic diseases, seaweeds have offered a promising resource to produce numerous bioactive secondary metabolites. Through in vivo investigations, Turbinaria decurrens acetone extract (AE) revealed its antidiabetic activity against alloxan-induced diabetic rats. Treatment of rats with T. decurrens AE at 300 and 150 mg/Kg doses revealed antihyperglycemic activity by reducing the elevated blood glucose level. A remarkable decrease in the liver, kidney functions, and hyperlipidemia related to diabetes were also detected. Administration of the same extract also showed a recovery in body weight loss, total protein, albumin, and haemoglobin levels compared with untreated diabetic rats. Furthermore, treatment of rats with the same extract improved liver and pancreas histopathological disorders related to diabetes. These effects may be attributed to the presence of bioactive phytochemicals and antioxidant components in T. decurrens AE mainly cyclotrisiloxane, hexamethyl, and cyclic diterpene 3,7,11,15-tetramethyl-2-hexadecen-1-ol (phytol alcohol). Besides, other valuable secondary metabolites, as phenols, flavonoids, alkaloids, terpenoids, steroid and glycosides, which were documented and published by the same authors in a previous study. The obtained results in the present study recommended using T. decurrens AE in developing medicinal preparations for treatment of diabetes and its related symptoms.

Antidiabetic potential of seaweed and their bioactive compounds: a review of developments in last decade

Diabetes Mellitus is a public health problem worldwide due to high morbidity and mortality rate associated with it. Diabetes can be managed by synthetic hypoglycemic drugs, although their persistent uses have several side effects. Hence, there is a paradigm shift toward the use of natural products having antidiabetic potential. Seaweeds, large marine benthic algae, are an affluent source of various bioactive compounds, including phytochemicals and antioxidants thus exhibiting various health promoting properties. Seaweed extracts and its bioactive compounds have antidiabetic potential as they inhibit carbohydrate hydrolyzing enzymes in vitro and exhibit blood glucose lowering effect in random and post prandial blood glucose tests in vivo. In addition, they have been associated with reduced weight gain in animals probably by decreasing mRNA expression of pro-inflammatory cytokines with concomitant increase in mRNA expression levels of anti-inflammatory cytokines. Their beneficial effect has been seen in serum and hepatic lipid profile and antioxidant enzymes indicating the protective role of seaweeds against free radicals mediated oxidative stress induced hyperglycemia and associated hyperlipidemia. However, the detailed and in-depth studies of seaweeds as whole, their bioactive isolates and their extracts need to be explored further for their health benefits and wide application in food, nutraceutical and pharmaceutical industries.

Arjunolic acid downregulates elevated blood sugar and pro-inflammatory cytokines in streptozotocin (STZ)-nicotinamide induced type 2 diabetic rats

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a worldwide health issue primarily due to failure of pancreatic β-cells to release sufficient insulin.

PURPOSE

The present work aimed to assess the antidiabetic potential of arjunolic acid (AA) isolated from Terminalia arjuna in type 2 diabetic rats.

STUDY DESIGN

After extraction, isolation and purification, AA was orally administered to type 2 diabetic Sprague Dawley rats to investigate antidiabetic effect of AA.

METHOD

T2DM was induced via single intraperitoneal injection of streptozotocin-nicotinamide (STZ-NIC) in adult male rats. After 10 days, fasting and random blood glucose (FBG and RBG), body weight (BW), food and water intake, serum C-peptide, insulin and glycated hemoglobin (HbA1c) was measured to confirm T2DM development. Dose dependent effects of orally administered AA (25 and 50 mg/kg/day) for 4 weeks was investigated by measuring BW variation, fasting and postprandial hyperglycemia, oral glucose tolerance test (OGTT), and levels of serum HbA1c, serum total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), high density lipoprotein (HDL), serum and pancreatic C-peptide, insulin, growth differentiation factor 15 (GDF-15), serum and pancreatic inflammatory cytokines.

RESULTS

The oral administration of AA in preclinical model of T2DM significantly normalized FBG and RBG, restored BW, controlled polyphagia, polydipsia and glucose tolerance. In addition, AA notably reduced serum HbA1c, TC, TG, LDL with non-significant increase in HDL. On the other hand, significant increase in serum and pancreatic C-peptide and insulin was observed with AA treatment, while serum and pancreatic GDF-15 were non-significantly altered in AA treated diabetic rats. Moreover, AA showed dose dependent reduction in serum and pancreatic proinflammatory cytokines including TNF-α, IL-1β and IL-6.

CONCLUSION

For the first time our findings highlighted AA as a potential candidate in type 2 diabetic conditions.

Evaluation of Antidiabetic Activity of Sargassum tenerrimum in Streptozotocin-Induced Diabetic Mice

Diabetes mellitus has become the most predominant disease in most of the developing and developed countries. Diabetes could occur at any stage of life for which a change in sedentary life style is the possible solution. Despite the introduction of several medications, to curtail the side effects associated with diabetes mellitus, there is no medication or treatment for complete cure. Existing medications and treatments are targeted to mitigate the intensity of the disease which abruptly could result in organ failure. Rather than the available types of treatments, natural medication is reported to produce commendable results. Extracts of many medicinal plants and seaweeds have been documented to possess anti-diabetic properties. A brown alga, S. tenerrimum, found on the west coast of India, is chosen in this study to analyse the anti-diabetic property of its methanolic extract. This extract was used to treat streptozotocin-induced diabetic mice. An experimental design was framed based on acute toxicity studies to determine the change in blood glucose level, body weight, lipid profile, liver enzymes (SGPT and SGOT) and the renal function markers (urea and creatinine). After 15 days of treatment, an increase in body weight and HDL cholesterol was observed while the total cholesterol, VLDL, LDL, serum triglyceride, SGOT, SGPT, creatinine and urea decreased with 250 mg/Kg.bw of S. tenerrimum methanolic extract in Streptozotocin-induced diabetic mice group. This difference is significant (p<0.05) when compared with a healthy non-diabetic mice group and a treated diabetic mice group. This proves that the methanolic extract of S. tenerrimum possess anti-diabetic property. Further research could explore the active compounds that can be used in the formulation of herbal medicine for diabetes mellitus.

Effect of Plantain Bulb's Extract-Beverage Blend on Blood Glucose Levels, Antioxidant Status, and Carbohydrate Hydrolysing Enzymes in Streptozotocin-Induced Diabetic Rats

The pharmacological properties of various parts of plantain trees have directed its use in folkloric management of diabetes and other human ailments. However, little is known about plantain bulb extract (PBE) and their mechanisms of action. This study evaluated the effect of PBE-beverage blends (including 1% and 2 % cocoa powder) sweetened with honey on blood glucose levels, antioxidant status, and carbohydrate hydrolysing enzyme activities in streptozotocin (STZ)-induced diabetic rats. Animals were selected at random and distributed into 7 groups (n=7), as follows: normal control (NC), untreated diabetic rats, diabetic rats treated with acarbose (STZ-ACA), diabetic rats administered PBE (STZ- PBE), diabetic rats administered honey and PBE (STZ-HPBE), diabetic rats administered 1% cocoa powder-with HPBE blend (STZ-CHPBE-1), and diabetic rats administered 2% cocoa powder with HPBE blend (STZ-CHPBE-2). Compared with the controls, untreated diabetic rats exhibited increased blood glucose levels and hydrolysing enzyme activities, and significant decreases in the activities of antioxidant (catalase, superoxide dismutase, glutathione-S-transferase, and glutathione peroxidase) enzyme and non-enzymatic (glutathione) antioxidants. However, changes in activities were comparatively reversed in all rats administered plantain bulb formulations. CHPBE-2 was slightly more effective than CHPBE-1. Overall, both blends could serve as nutraceutical and/or functional drinks in the management of diabetes.

Beneficial Effects of Algerian Green Alga Ulva lactuca and Its Hydroethanolic Extract on Insulin Resistance and Cholesterol Reverse Transport in High-Fat/Streptozotocin Diabetic Rats

The aim of this study was to evaluate the impact of the green algae Ulva lactuca and its hydroethanolic extract on insulin resistance and cholesterol reverse transport in type 2 diabetic (T2D) rats. Rats had T2D induced by a high-fat diet (HFD) for 5 weeks followed by intraperitoneal injection of streptozotocin. Diabetic rats were divided into three groups and were fed a HFD in the presence or absence of 1% alga (HFD-Alg) or 1% of its hydroethanolic extract (HFD-Ext), for 4 weeks. The control group consumed 20% casein combined with 5% lipids. Hyperglycemia, insulin resistance, hypercholesterolemia, and hypertriglyceridemia were noted in HFD rats vs control rats. Whole alga and its extract decreased these parameters vs the HFD. Moreover, fecal total cholesterol and triacylglycerols levels were lowered in HFD group vs C group, but were increased with HFD-Alg vs HFD. Compared with the Control, the HFD group had decreased lecithin:cholesterol acyltransferase (LCAT) activity, apolipoprotein A-I (ApoA-I), high-density lipoprotein (HDL₃)-phospholipids (PL), and HDL₂-cholesteryl ester (CE) levels, but increased HDL₃-unesterified cholesterol (UC) levels. Furthermore, compared with the HFD group, the HFD-Alg and HFD-Ext groups had increased LCAT activity, ApoA-I, HDL₃-PL, and HDL₂-CE levels and decreased HDL₃-UC levels. In addition, in the HFD-Ext group, LCAT activity and ApoA-1 levels were decreased vs the HFD-Alg whereas HDL₃-UC levels were increased. In conclusion, these results indicate that U. lactuca and its hydroethanolic extract have curative effect on T2D. Therefore, this alga could be considered a functional food supplement for the treatment and prevention of diabetes.

Antidiabetic Potential of Marine Brown Algae-a Mini Review

Marine algae are an important source of bioactive metabolites in drug development and nutraceuticals. Diabetes mellitus is a metabolic disorder and the third leading cause of death worldwide due to lifestyle changes associated with rapid urbanization. Due to the adverse side effects of currently available antidiabetic drugs, search for an effective natural-based antidiabetic drug is important to combat diabetes and its complications. Therefore, in lieu with herbal drug development, it is important to find the potential benefits of seaweeds for the management of type 2 diabetes as they are underexplored yet in Sri Lanka. Among the marine seaweeds, natural bioactive compounds are abundant in brown algae with potentials in application as active ingredients in drug leads and nutraceuticals. Bioactive secondary metabolites are derived from numerous biosynthetic pathways of marine algae which contribute to various chemical and biological properties. Phlorotannins present in marine brown algae exhibited antidiabetic activities through different mechanisms such as the inhibitory effect of enzyme targets mainly by inhibiting the enzymes such as α-amylase, α-glucosidase, angiotensin-converting enzymes (ACE), aldose reductase, dipeptidyl peptidase-4, and protein tyrosine phosphatase 1B (PTP 1B) enzyme. In addition, phlorotannins derived from brown algae have the ability to reduce diabetic complications. Hence, the present review focuses on the different antidiabetic mechanisms of secondary bioactive compounds present in marine brown algae.

Sargassum hystrix as a Source of Functional Food to Improve Blood Biochemistry Profiles of Rats under Stress

This study was conducted to determine the influence of Sargassum hystrix powder (SHP) as an alternative source of functional food for treating in vivo stress by measuring levels of glucose, triacylglycerol, total cholesterol, and cortisol, and liver histopathology. Wistar rats aged 3 months and weighing 150~200 g were divided into 7 groups: normal control, fasting control, negative control (stress without adaptogen), and 4 experimental conditions (stress+0.18 mg/kg diazepam, stress+450 mg/kg pellet, stress+mixture of pellet with SHP 450 mg/kg, and stress+450 mg/kg of SHP). Intake of liquids and and body weight were measured daily. Blood samples were collected on day 0 (baseline), day 5, and day 10 to analyze levels of glucose, triacylglycerol, cholesterol, and cortisol. On day 10, rats were euthanized and livers were collected to observe the severity of inflammation. The results indicated that rats receiving SHP 450 mg/kg and the mixture of pellet with SHP 450 mg/kg showed a similar ability as those receiving diazepam 0.18 mg/kg to cope with stress, indicated by an improvement in all blood biochemistry parameters. Supplementation with SHP 450 mg/kg can be used as an alternative source of functional food for overcoming oxidative stress, as indicated by its ability to improve levels of blood glucose, triacylglycerol, total cholesterol, and cortisol, and to improve liver histology by decreasing severity of liver inflammation.