Improvement in Serum Biochemical Alterations and Oxidative Stress of Liver and Pancreas following Use of Royal Jelly in Streptozotocin-Induced Diabetic Rats

Recommendations for nutritional supplements for dry eye disease: current advances

Dry eye disease (DED) represents a prevalent ocular surface disease. The development of effective nutritional management strategies for DED is crucial due to its association with various factors such as inflammation, oxidative stress, deficiencies in polyunsaturated fatty acids (PUFAs), imbalanced PUFA ratios, and vitamin insufficiencies. Extensive research has explored the impact of oral nutritional supplements, varying in composition and dosage, on the symptoms of DED. The main components of these supplements include fish oils (Omega-3 fatty acids), vitamins, trace elements, and phytochemical extracts. Beyond these well-known nutrients, it is necessary to explore whether novel nutrients might contribute to more effective DED management. This review provides a comprehensive update on the therapeutic potential of nutrients and presents new perspectives for combination supplements in DED treatment.

Thymoquinone mitigates obesity and diabetic parameters through regulation of major adipokines, key lipid metabolizing enzymes and AMPK/p-AMPK in diet-induced obese rats

The present study was designed to evaluate the anti-obesity and anti-hyperglycemic activity of Thymoquinone (ThyQ) isolated from Nigella sativa seeds. Male Wistar rats were randomly divided into five groups and fed either normal pellet diet or high-fat diet (HFD) for 18 weeks and water ad-libitum. Group I: normal pellet diet (NPD)-fed, Group II: high-fat diet (HFD)-fed, Group III: HFD-fed-ThyQ (20 mg)-treated, Group IV: HFD-fed-ThyQ (40 mg)-treated and Group V: HFD-fed-Orlistat (5 mg)-treated group. Intervention with ThyQ started from 12th week onwards to HFD-fed rats of group III and IV. ThyQ administration significantly (p < 0.01) mitigated body weight gain, blood glucose, insulin level, serum and liver lipids (except HDL) and improved glucose tolerance and insulin sensitivity as evaluated by oral glucose tolerance test (OGTT), homeostasis model assessment-insulin resistance (HOMA-IR) and insulin tolerance test (ITT). Furthermore, ThyQ significantly (p < 0.01) diminished serum aspartate transaminase (AST), alanine transaminase (ALT), acetyl-CoA carboxylase (ACC), plasma leptin, resistin and visfatin levels but enhanced lipoprotein lipase (LPL) and adiponectin levels. RT-PCR analysis demonstrated down-regulated mRNA expression of sterol regulatory element-binding proteins-1c (SREBP-1c), CCAAT/enhancer-binding protein-α (C/EBP-α) and fatty acid synthase (FAS) but upregulation of Insulin receptor substrate-1 (IRS-1).Western blot analysis displayed phosphorylation of adenosine monophosphate activated protein kinase (AMPK) in ThyQ-treated rats. Liver microtome sections of HFD-fed rats showed degenerated hepatocytes with high lipid stores while that of adipose tissue sections displayed large, fat-laden adipocytes, however, these histological changes were considerably attenuated in ThyQ-treated groups. Together these findings demonstrate that ThyQ can be a valuable therapeutic compound to potentially alleviate diet-induced obesity, hyperglycemia and insulin resistance.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-023-03847-x.

Chronic supplementation of noni in diabetic type 1-STZ rats: effects on glycemic levels, kidney toxicity and exercise performance

Noni is a fruit with potential medicinal use preventing elevated blood glucose levels in diabetes mellitus. Its effects have been attributed to an antioxidant property in several other diseases. However, the effects of noni-chronic supplementation on exercise performance in the presence of diabetes conditions are not known. Thirty-two male Wistar rats were used to verify the effects of chronic noni (Morinda citrifolia L) juice administration on glycemia, triglyceride levels, and its relation to physical performance. In addition, it was verified if chronic noni supplementation is safe for clinical use through kidney morphology analysis. In half of the rats, diabetes mellitus (DM) was induced with STZ. All rats were submitted to an incremental workload running test (IWT) until fatigued so that oxygen consumption and performance indexes (exercise time to fatigue and workload) could be analyzed before noni administration. Then, the control and DM groups received a placebo (saline solution) or noni juice (dilution 2:1) at a dose of 2 mL/kg once a day for 60 days. The result was four groups: control + placebo (CP), control + noni (CN), DM + placebo (DMP), and DM + noni (DMN). Our dose was based on in previous study by Nayak et al. (2011) that observed a significant reduction in glycemia with 2 ml/kg of the noni juice without any toxicity effect cited. Groups were then given a third IWT to verify the effect of the noni juice on exercise performance (exercise time to fatigue, workload, maximal oxygen consumption) and glycemia. Twenty-four hours after the third test, all animals were euthanized and blood and kidneys were removed for posterior analysis. The DM induction with STZ impaired the performance by 39%. Noni administration improved the time to fatigue and workload in DM rats beyond reducing hyperglycemia. These results could be associated with an improved energy efficiency promoted by noni ingestion, since the oxygen consumption was not different between the groups, although the exercise was longer in animals with noni ingestion. Our results provided evidence that chronic noni administration causes kidney damage since increased Bowman's space area in the control rats, suggesting glomerular hyperfiltration at the same magnitude as the non-treated DM group.In conclusion, chronic noni ingestion promoted glycemic control and improved the performance in DM rats but caused kidney toxicity.

Antidiabetic Potential of Sinigrin Against Streptozotocin-Induced Diabetes via Modulating Inflammation and Oxidative Stress

Diabetes mellitus (DM) is a common metabolic disorder which arises due to the improper carbohydrate metabolism, decreased secretion/activity of insulin, and genetic abnormalities, which result in the increased blood glucose level generally known as hyperglycemia. Diabetes holds an increased global prevalence in each year and is responsible for increased morbidity and mortality rates. Hence, the current investigation focusses to assess the antidiabetic potential of sinigrin on diabetic animal model through the suppression of inflammation. Diabetes was initiated to the animals via administering streptozotocin (STZ) and supplemented with the sinigrin at 25- and 50-mg/kg dose via oral route. The diabetic rats demonstrated the elevated glucose, food and water intake, kidney and liver weights, and reduced bodyweight and depleted insulin status. The sinigrin treatment remarkably improved and modulated these changes in diabetic animals. Additionally, the sinigrin supplementation also modulated the changes in glucose-6-phosphatase; fructose 1,6-bisphosphatase; AST; ALT; creatinine; and inflammatory mediators in the STZ-provoked diabetic animals. The levels of hexokinase, protein, and antioxidants also improved by the sinigrin treatment. The histological investigations of pancreas also witnessed the therapeutic actions of sinigrin, which is supported by the findings of biochemical examinations. Therefore, it was clear that the sinigrin supplementation displayed remarkable antidiabetic effect on STZ-initiated diabetic animals via modulating inflammation and other biochemical changes, which recommends that sinigrin could be a talented candidate for diabetes management in the future.

Molecular docking analysis and anti-hyperglycaemic activity of Synacinn™ in streptozotocin-induced rats

Synacinn™ is a standardized polyherbal supplement formulated from Cinnamomum zeylanicum Blume, Curcuma zanthorrhiza Roxb., Syzygium polyanthum (Wight) Walp., Orthosiphon stamineus Benth. and Andrographis paniculata (Burm.f.) Nees. It is designed for the synergistic treatment of diabetes mellitus and its complications. Although the beneficial effects are yet to be verified scientifically, it is traditionally used to improve general health in patients with diabetes. This study aimed to evaluate the anti-hyperglycemic effects of Synacinn™ in a streptozotocin-induced type 1 diabetes rat model. Initially, Synacinn™ was used for in vivo acute oral toxicity tests and 14 day repeated dose toxicity tests to determine the toxicity levels. An efficacy study of Synacinn™ was carried out via the oral administration of 10, 50, 100, 250, and 250 (b.i.d.) mg kg⁻¹ doses to streptozotocin-induced diabetic rats. After 28 days, blood serum was collected to measure the fasting blood glucose, triglyceride, cholesterol, alanine aminotransferase, alkaline phosphatase, creatinine, and uric acid levels. The liver, kidney, and pancreas structures were histopathologically analyzed. In silico binding interaction studies of five phytochemicals in Synacinn™ identified via HPLC with glucokinase were performed using molecular docking analysis. The results showed that although no mortality was observed during the acute oral toxicity tests, notable damage to the liver and kidney occurred during the 14 day repeated dose testing at Synacinn™ levels of 600 mg kg⁻¹ and 2000 mg kg⁻¹. Treatment with 250 mg kg⁻¹ (b.i.d.) Synacinn™ of the streptozotocin-induced type 1 diabetic rats significantly (p < 0.05) improved the fasting blood glucose (59%), triglyceride (58%), cholesterol (47%), alanine aminotransferase (60%), alkaline phosphatase (90%), and creatinine (32%) levels. Synacinn™ also improved the relative weights of liver (35%), kidney (36%), and pancreatic (36%) tissue. Histological analysis showed improvements in the conditions of the central vein of the liver, the kidney Bowman's capsule and glomerulus, and the pancreatic islets of Langerhans. HPLC analysis of a standardized extract identified five active phytochemicals: andrographolide (17.36 mg g⁻¹), gallic acid (11.5 mg g⁻¹), curcumin (2.75 mg g⁻¹), catechin (3.9 mg g⁻¹), and rosmarinic acid (5.54 mg g⁻¹). Molecular docking studies with glucokinase showed that andrographolide yields the highest binding energy (−12.1 kcal mol⁻¹), followed by catechin (−10.2 kcal mol⁻¹), rosmarinic acid (−8.6 kcal mol⁻¹), curcumin (−7.8 kcal mol⁻¹), and gallic acid (−5.6 kcal mol⁻¹). These current findings suggest that Synacinn™ at a dose of 250 mg kg⁻¹ was non-toxic to rats. A twice-daily 250 mg kg⁻¹ dose of Synacinn™ is an effective anti-hyperglycemic agent, lowering blood glucose, triglyceride, and cholesterol levels, and assisting the recovery of organ impairment caused by streptozotocin in type 1 diabetic rats.

Synacinn™, a standardized polyherbal supplement, was shown to improve hyperglycemic conditions and related complications in STZ-induced rats.

The Effects and Mechanism of Quercetin Dietary Supplementation in Streptozotocin-Induced Hyperglycemic Arbor Acre Broilers

Quercetin, a flavonoid found in fruits and vegetables, is widely distributed as a secondary metabolite in the plant kingdom. Oxidative stress plays a role in the pathogenesis of diabetes mellitus (DM). The present study investigated the effects of quercetin dietary supplementation on streptozotocin- (STZ-) induced hyperglycemic Arbor Acre (AA) broilers by determining the levels of fasting blood glucose (FBG), fasting insulin (FINS), biochemical indicators, oxidative stress markers, inflammatory cytokines content, antioxidant enzymes activities in tissues, and mRNA expression of genes relating to the insulin signaling pathway. Three hundred one-day-old healthy AA broilers were randomly assigned into 5 treatments; A, control healthy broilers; B, STZ-induced broilers; C, STZ-induced broiler dietary supplemented with 0.02% quercetin; D, STZ-induced broiler dietary supplemented with 0.04% quercetin; and E, STZ-induced broiler dietary supplemented with 0.06% quercetin. The results showed that quercetin supplementation relieved the side effects of STZ-induced oxidative stress by changing activities of antioxidant enzymes, decreasing malondialdehyde (MDA) and nitric oxide (NO) levels, activating expression of genes relating to PI3K/PKB signaling pathway that modulate glucose metabolism and reduce oxidative damage, thereby decreasing FBG and increasing FINS levels. These findings suggest that quercetin exhibits a protective effect in STZ-induced hyperglycemic AA broilers via decreasing oxidative stress.

New Insights into the Biological and Pharmaceutical Properties of Royal Jelly

Royal jelly (RJ) is a yellowish-white and acidic secretion of hypopharyngeal and mandibular glands of nurse bees used to feed young worker larvae during the first three days and the entire life of queen bees. RJ is one of the most appreciated and valued natural product which has been mainly used in traditional medicines, health foods, and cosmetics for a long time in different parts of the world. It is also the most studied bee product, aimed at unravelling its bioactivities, such as antimicrobial, antioxidant, anti-aging, immunomodulatory, and general tonic action against laboratory animals, microbial organisms, farm animals, and clinical trials. It is commonly used to supplement various diseases, including cancer, diabetes, cardiovascular, and Alzheimer's disease. Here, we highlight the recent research advances on the main bioactive compounds of RJ, such as proteins, peptides, fatty acids, and phenolics, for a comprehensive understanding of the biochemistry, biological, and pharmaceutical responses to human health promotion and life benefits. This is potentially important to gain novel insight into the biological and pharmaceutical properties of RJ.

Renal Tissue Damages and Its Antioxidant Status Improved by Crab Shell Extract in Streptozotocin-induced Diabetic Rat

BACKGROUND

Diabetic nephropathy is a complex and multifactorial adverse effect of diabetes mellitus (DM). Crab shell as a natural product is supposed to have antioxidant effect which is one of the important mechanisms to improve DM. The aim of this study was to investigate the effect of crab shell extract (CSE) on the histopathology and antioxidant status of kidney in diabetic rats.

MATERIALS AND METHODS

Forty-two adult Wistar rats (210 ± 10 g) were divided into six groups (n = 7). Streptozotocin (50 mg/kg) was administered interaperitonealy (IP) for inducing diabetes. Rats were treated for 14 days by CSE with 100, 200, and 400 mg/kg doses IP. Fasting blood glucose, body, and renal weight were evaluated. The antioxidant status of kidney's tissue was evaluated by determining the level of ferric-reducing antioxidant power (FRAP). Furthermore, urine samples were used to determine nitric oxide (NO) levels. Microscopic slides were prepared to compare kidney histology between groups. Data were analyzed by one-way analysis of variance with post hoc Tukey's test, and P < 0.05 was considered statistically significant.

RESULTS

CSE induced a significant reduction in blood glucose (P = 0.01) and a significant increase in total antioxidant capacity (FRAP) (P = 0.004). Furthermore, urine NO was decreased significantly (P = 0.000). The extract improved renal tissue changes caused by diabetes.

CONCLUSION

CSE improved antioxidant status and diabetic histological changes of rat kidney, and it could be an alternative complementary therapy in diabetic-associated disorders.

Protective effects of resveratrol on biomarkers of oxidative stress, biochemical and histopathological changes induced by sub-chronic oral glyphosate-based herbicide in rats

The aim of this sub-chronic toxicity study is to determine the protective effects of Resveratrol (Res) on oxidative stress, biochemical and histopathological changes induced by glyphosate-based herbicide (GBH) in the blood, brain, heart, liver and renal tissues. A total of 28 male Wistar rats were equally divided into 4 groups so that each group included 7 rats. In the study, Group I (control group) was given normal rodent feed and tap water ad libitum. Group II (Res group) was given Res 20 mg kg-1, Group III (GBH group) was given GBH of 375 mg kg-1 to achieve 1/10 of Lethal Dose 50% (LD50), and Group IV (Res + GBH) was given Res 20 mg kg-1 and GBH 375 mg kg-1 with oral gavage once a day for 8 weeks. While GBH decreased the glutathione (GSH) levels in the blood, brain, heart, liver and renal tissues, it significantly increased malondialdehyde (MDA) levels. In contrast, the aforementioned parameters were seen to recover in the group to which Res was administered. Moreover, it was observed that Res improved the histopathological changes induced by GBH in rat tissues. In conclusion, Res prevents oxidative stress caused by GBH by preventing lipid peroxidation (LPO) and boosting the antioxidant defense system and decreases the damage in the brain, heart, liver and renal tissues of Wistar rats.

Effectiveness of royal jelly supplementation in glycemic regulation: A systematic review

BACKGROUND

Royal jelly (RJ) has been observed to have therapeutic properties in diabetic individuals, including the reduction of high blood sugar. This systematic review synthesized existing evidence to investigate the effectiveness of RJ supplementation in managing measures of blood glucose.

AIM

To determine the effectiveness of RJ supplementation on glycemic responses in healthy and non-insulin dependent diabetic adults, as well as animal models of diabetes.

METHODS

This was a systematic review employing the PRISMA strategy. Peer-reviewed, published articles were extracted from several databases using key words related to target population, intervention and outcome and hand-selected for inclusion. Included articles proceeded to data extraction phase, where information on target parameters and effectiveness of treatment was summarized. Following this, the risk of bias for each included study was evaluated. Then, the long-term and immediate effectiveness of RJ supplementation in glycemic control were assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool, which rates the quality of evidence.

RESULTS

Of 168 articles extracted from database searching, eighteen were included for analysis in this systematic review. Across the studies, studied populations, intervention styles and outcome measures were largely heterogeneous. Despite this, the results in studies indicate a general trend of positive effect of RJ in glycemic regulation in vitro and in vivo. Additionally, some dose-dependent glycemic effects were observed, along with some large effect sizes. The risk of bias for human and animal studies is generally low-unclear risk, although lack of blinding is a serious concern in both categories. Overall, as per the GRADE tool, the quality of evidence is low, and very low for long-term and immediate effectiveness of RJ, respectively. A major limitation affecting evidence quality is the heterogeneity among included studies. Fasting blood glucose and glucose clearance appear to be most affected by RJ supplementation.

CONCLUSION

Quality of evidence suggesting that RJ is an effective modulator of glycemic regulation is low for long-term effects of RJ, and very low for immediate effects.

Antioxidant Potential of Propolis, Bee Pollen, and Royal Jelly: Possible Medical Application

Honeybees products comprise of numerous substances, including propolis, bee pollen, and royal jelly, which have long been known for their medicinal and health-promoting properties. Their wide biological effects have been known and used since antiquity. Bee products are considered to be a potential source of natural antioxidants such as flavonoids, phenolic acids, or terpenoids. Nowadays, the still growing concern in natural substances capable of counteracting the effects of oxidative stress underlying the pathogenesis of numerous diseases, such as neurodegenerative disorders, cancer, diabetes, and atherosclerosis, as well as negative effects of different harmful factors and drugs, is being observed. Having regarded the importance of acquiring drugs from natural sources, this review is aimed at updating the current state of knowledge of antioxidant capacity of selected bee products, namely, propolis, bee pollen, and royal jelly, and of their potential antioxidant-related therapeutic applications. Moreover, the particular attention has been attributed to the understanding of the mechanisms underlying antioxidant properties of bee products. The influence of bee species, plant origin, geographic location, and seasonality as well as type of extraction solutions on the composition of bee products extracts were also discussed.

Adaptogenic potential of royal jelly in liver of rats exposed to chronic stress

Restraint and cold stress increase both corticosterone and glycemia, which lead to oxidative damages in hepatic tissue. This study assessed the effect of royal jelly (RJ) supplementation on the corticosterone level, glycemia, plasma enzymes and hepatic antioxidant system in restraint and cold stressed rats. Wistar rats were allocated into no-stress, stress, no-stress supplemented with RJ and stress supplemented with RJ groups. Initially, RJ (200mg/Kg) was administered for fourteen days and stressed groups were submitted to chronic stress from the seventh day. The results showed that RJ supplementation decreases corticosterone levels and improves glycemia control after stress induction. RJ supplementation also decreased the body weight, AST, ALP and GGT. Moreover, RJ improved total antioxidant capacity, SOD activity and reduced GSH, GR and lipoperoxidation in the liver. Thus, RJ supplementation reestablished the corticosterone levels and the hepatic antioxidant system in stressed rats, indicating an adaptogenic and hepatoprotective potential of RJ.

Preventive effects of royal jelly against anaphylactic response in a murine model of cow's milk allergy

CONTEXT

Royal jelly (RJ) has long been used to promote human health.

OBJECTIVE

The current study investigated the preventive effects of RJ against the development of a systemic and intestinal immune response in mice allergic to cow's milk proteins.

MATERIALS AND METHODS

Balb/c mice treated orally for seven days with RJ at doses of 0.5, 1 and 1.5 g/kg were sensitized intraperitoneally with β-lactoglobulin (β-Lg). Serum IgG and IgE anti-β-Lg were determined by an enzyme-linked immunosorbent assay (ELISA). Plasma histamine levels, symptom scores and body temperature were determined after in vivo challenge to β-Lg. Jejunums were used for assessment of local anaphylactic responses by an ex vivo study in Ussing chambers and morphologic changes by histological analysis.

RESULTS

RJ significantly decreased serum IgG (31.15-43.78%) and IgE (64.28-66.6%) anti-β-Lg and effectively reduced plasma histamine level (66.62-67.36%) (p < 0.001) at all the doses tested. Additionally, no clinical symptoms or body temperature drops were observed in RJ-pretreated mice. Interestingly, RJ significantly reduced (p < 0.001) intestinal dysfunction by abolishing the secretory response (70.73-72.23%) induced by sensitization and prevented length aberrations of jejunal villi by 44.32-59.01% (p < 0.001).

DISCUSSION AND CONCLUSIONS

We speculate that using RJ may help prevent systemic and anaphylactic response in allergic mice. These effects may be related to its inhibitory effects on the degranulation of mast cells.