Antihypertriglyceridemia and anti-inflammatory activities of monascus-fermented dioscorea in streptozotocin-induced diabetic rats

Natural pigment from Monascus: The production and therapeutic significance

OBJECTIVE

The present review highlights the advantages of using natural colorant over the synthetic one. We have discussed the fermentation parameters that can enhance the productivity of Monascus pigment on agricultural wastes.

BACKGROUND

Food industry is looking for natural colours because these can enhance the esthetic value, attractiveness, and acceptability of food while remaining nontoxic. Many synthetic food colours (Azorubine Carmoisine, quinoline) have been prohibited due to their toxicity and carcinogenicity. Increasing consumer awareness towards the food safety has forced the manufacturing industries to look for suitable alternatives. In addition to safety, natural colorants have been found to have nutritional and therapeutic significance. Among the natural colorants, microbial pigments can be considered as a viable option because of scalability, easier production, no seasonal dependence, cheaper raw materials and easier extraction. Fungi such as Monascus have a long history of safety and therefore can be used for production of biopigments.

METHOD

The present review summarizes the predicted biosynthetic pathways and pigment gene clusters in Monascus purpureus.

RESULTS

The challenges faced during the pilot-scale production of Monascus biopigment and taming it by us of low-cost agro-industrial substrates for solid state fermentation has been suggested.

CONCLUSION

Keeping in mind, therapeutic properties of Monascus pigments and their derivatives, they have huge potential for industrial and pharmaceutical application.

APPLICATION

Though the natural pigments have wide scope in the food industry. However, stabilization of pigment is the greatest challenge and attempts are being made to overcome this by complexion with hydrocolloids or metals and by microencapsulation.

Investigation of the In Vitro Antioxidant Potential Of Polyphenolic-Rich Extract of Artocarpus heterophyllus Lam Stem Bark and Its Antidiabetic Activity In Streptozotocin-Induced Diabetic Rats

Artocarpus heterophyllus Lam (Moraceae) stem bark has been used locally in managing diabetes mellitus with sparse scientific information. This study investigates the in vitro antioxidant potential of polyphenolic-rich extract of A heterophyllus stem bark as well as its antidiabetic activity in streptozotocin-induced diabetic rats. Fifty male Wistar rats were used with the induction of diabetes by a single intraperitoneal injection of streptozotocin (45 mg/kg body weight) and were orally administered 400 mg/kg free and bound phenols of A heterophyllus stem bark. The animals were sacrificed on the 28th day of the experiment using the cervical dislocation method; antihyperglycemia and anti-inflammatory parameters were subsequently assessed. The polyphenolic extracts demonstrated antioxidant potentials (such as hydrogen peroxide and diphenyl-1-picrylhydrazyl), as well as strong inhibitory activity against amylase and glucosidase. There was a significant (P < .05) increase in glycogen, insulin concentration, pancreatic β-cell scores (HOMA-β), antioxidant enzymes and hexokinase activities, as well as glucose transporter concentration in diabetic animals administered the extracts and metformin. Also, a significant (P < .05) reduction in fasting blood glucose, lipid peroxidation, glucose-6-phosphatase, and all anti-inflammatory parameters were observed in diabetic rats administered the extracts and metformin. The extracts demonstrated antidiabetic potential, which may be useful in the management of diabetes mellitus

Red rice koji extract alleviates hyperglycemia by increasing glucose uptake and glucose transporter type 4 levels in skeletal muscle in two diabetic mouse models

Background

Red rice koji (RRK), prepared by growing Monascus species on steamed rice, has been reported to lower blood glucose levels in diabetic animal models. However, the action mechanism is not yet completely understood.

Objective

The objective of this study was to examine the mechanism underlying the hypoglycemic action of RRK extract in two diabetic animal models: the insulin-deficiency mice, where the insulin deficiency was induced by streptozotocin (STZ), and insulin-resistance mice, where the insulin resistance was induced by a high-fat diet (HFD).

Design

Low (12.5 mg/kg body weight [BW]) and high (50.0 mg/kg BW) doses of RRK extract were orally administered to the mice for 10 successive days (0.25 mL/day/mouse). The protein expression levels of glucose transporter type 4 (GLUT4) in the skeletal muscle and glucose transporter type 2 (GLUT2) in the liver were measured. Blood glucose (BG) levels of STZ-treated mice in insulin tolerance test (ITT) and BG and insulin levels of HFD-fed mice in intraperitoneal glucose tolerance test (IPGTT) were investigated.

Results

In the STZ-treated mice, oral administration of RRK extract lowered BG levels and food intake but increased plasma 1,5-anhydroglucitol level. Moreover, the RRK extract lowered the BG levels of STZ-treated mice as measured by ITT. In the HFD-fed mice, we confirmed that the orally administered RRK extract lowered the BG and the homeostasis model assessment index for insulin resistance. Furthermore, the RRK extract lowered the BG and insulin levels of HFD-fed mice in IPGTT. Regarding the protein levels of GLUT, the orally administered RRK extract increased the GLUT4 level in the skeletal muscle; however, the RRK extract did not alter the GLUT2 level in the liver of either the STZ-treated or the HFD-fed mice.

Discussion

Our study demonstrates that RRK extract can improve impaired glucose tolerance in mouse models of diabetes by enhancing GLUT4 expression in skeletal muscle.

Conclusion

These results suggest that RRK extract could potentially be a functional food for the treatment of diabetes mellitus.

Multifaceted Applications of Microbial Pigments: Current Knowledge, Challenges and Future Directions for Public Health Implications

Microbial oddities such as versatile pigments are gaining more attention in current research due to their widely perceived applications as natural food colorants, textiles, antimicrobial activities, and cytotoxic activities. This indicates that the future generation will depend on microbial pigments over synthetic colorants for sustainable livelihood. Although several reviews have detailed the comprehensive applications of microbial pigments extensively, knowledge on several aspects of pigmented microbes is apparently missing and not properly reviewed anywhere. Thus, this review has been made to provide overall knowledge on biodiversity, distribution, pathogenicity, and ecological and industrial applications of microbial pigments as well as their challenges and future directions for food, industrial, and biomedical applications. Meticulously, this compendious review treatise on the pigments from bacteria, fungi, yeasts, and microalgae includes reports from the 1970s to 2018. A total of 261 pigment compounds produced by about 500 different microbial species are included, and their bioactive nature is described.

Antihyperglycemic activity of Albizzia lebbeck bark extract in streptozotocin-nicotinamide induced type II diabetes mellitus rats

Introduction:

Albizzia lebbeck (L.) Benth. (Family - Leguminosae) extract is a proven mast cell stabilizing agent. Mast cells are involved in the inflammatory processes leading to the diabetes mellitus.

Aim:

To evaluate the effect of A. lebbeck against experimentally induced type 2 diabetes mellitus in rats.

Materials and Method:

Female Sprague-Dawley rats were randomly allocated to six groups (n = 6). Diabetes was induced by single intraperitoneal injection of streptozotocin (50 mg/kg) given after 15 min of nicotinamide administration (110 mg/kg). Treatment with methanolic extract of A. lebbeck bark (MEAL) and metformin drug as standard was given for 21 days. Serum glucose (GLU) levels were measured on the 0 day and on 1^st, 7^th, 14^th and 21^st day after diabetes induction. After completion of study period, various biochemical parameters in serum such as - GLU, lipid profile, urea and creatinine were estimated. One-way analysis of variance followed with post-hoc Dunnett's test was used to analyse the data. Statistical significance for the values was set at P< 0.05.

Results:

MEAL significantly decreased the level of serum GLU, creatinine, urea, cholesterol, triglycerides, low-density lipoprotein-cholesterol, very low-density lipoprotein-cholesterol and increased high-density lipoprotein levels.

Conclusion:

A. lebbeck bark extract showed antihyperglycaemic activity along with antihyperlipidemic effect.

Modulation of antioxidant status in streptozotocin-induced diabetic male Wistar rats following intake of red palm oil and/or rooibos

OBJECTIVE

To investigate the role of red palm oil (RPO), rooibos tea extract (RTE) and their combined treatment (RPO + RTE) on antioxidant status in streptozotocin (STZ)-induced diabetic rats.

METHODS

Diabetes mellitus was induced by a single administration of streptozotocin (50 mg/kg) and the rats were treated for 7 weeks. Antioxidant enzymes [catalase (CAT), glutathione peroxidase (GPx), superoxide dismutase (SOD)], antioxidant capacity [trolox equivalence antioxidant capacity (TEAC), oxygen radical absorbance capacity (ORAC)] as well as total protein, albumin, globulin, total glutathione, conjugated diene and thiobarbituric acid reactive substances (TBARS) were investigated.

RESULTS

Treatment with RPO, RTE and RPO + RTE significantly (p>0.05) improved liver SOD and plasma ORAC in the diabetic rats. Similarly, diabetic rats treated with RTE and RPO + RTE enhanced liver GPx. A significant (P<0.05) increase in the plasma TBARS in the diabetic control group was observed when compared with the normal control group. Treatment of diabetic rats with RTE and RPO + RTE reduced plasma TBARS to a level not significantly different at P<0.05 from the normal control group.

CONCLUSIONS

The results revealed the anti-oxidative potentials of red palm oil, rooibos and their combination in diabetic conditions and hence, they could be useful in the management of diabetes and its complications.

Ice plant (Mesembryanthemum crystallinum) improves hyperglycaemia and memory impairments in a Wistar rat model of streptozotocin-induced diabetes

BACKGROUND

Ice plant (Mesembryanthemum crystallinum) has been used as an anti-diabetic agent in Japan because it contains d-pinitol. The efficacy of ice plant in the regulation of blood glucose is unclear at present. Recently, memory impairment and development of Alzheimer's disease found in diabetic patients are thought to be caused by high blood glucose. The mechanism by which ice plant protects against the impairment of memory and learning abilities caused by high blood glucose remains unclear. The aim of this study was to evaluate the protection of ice plant water extracts (IPE) and D-pinitol against memory impairments in a Wistar rat model of streptozotocin (STZ)-induced diabetes. We hypothesised that IPE and D-pinitol could suppress blood glucose and elevate insulin sensitivity in these rats.

RESULTS

For memory evaluation, IPE and D-pinitol also improved the passive avoidance task and the working memory task. In addition, inhibition of acetylcholinesterase activity in hippocampus and cortex was found in this rat model administered IPE or D-pinitol. IPE and D-pinitol also markedly elevated superoxide dismutase activity against oxidative stress and reduced malondialdehyde production in hippocampus and cortex of the rats.

CONCLUSION

These findings indicated that IPE and D-pinitol possess beneficial effects for neural protection and memory ability in a rat model of diabetes.

Evaluation of In Vitro Anti-Inflammatory Activities and Protective Effect of Fermented Preparations of Rhizoma Atractylodis Macrocephalae on Intestinal Barrier Function against Lipopolysaccharide Insult

Lipopolysaccharide (LPS), a potent inducer of systemic inflammatory responses, is known to cause impairment of intestinal barrier function. Here, we evaluated the in vitro protective effect of an unfermented formulation of Rhizoma Atractylodis Macrocephalae (RAM), a traditional Chinese herbal medicine widely used in the treatment of many digestive and gastrointestinal disorders, and two fermented preparations of RAM, designated as FRAM-1 (prepared in Luria-Bertani broth) and FRAM-2 (prepared in glucose), on intestinal epithelial cells (IECs) against LPS insult. In general, fermented formulations, especially FRAM-2, but not unfermented RAM, exerted an appreciable protective effect on IECs against LPS-induced perturbation of membrane resistance and permeability. Both fermented formulations exhibited appreciable anti-inflammatory activities in terms of their ability to inhibit LPS-induced gene expression and induced production of a number of key inflammatory mediators and cytokines in RAW 264.7 macrophage cells. However, in most cases, FRAM-2 exhibited stronger anti-inflammatory effects than FRAM-1. Our findings also suggest that suppression of nuclear factor- κ β (NF- κ β ) activity might be one of the possible mechanisms by which the fermented RAM exerts its anti-inflammatory effects. Collectively, our results highlight the benefits of using fermented products of RAM to protect against LPS-induced inflammatory insult and impairment in intestinal barrier function.