Anti-inflammatory potential of royal jelly in multiple sclerosis disease: a double randomized clinical trial

Abstract

Introduction:

Multiple sclerosis (MS) is a chronic, autoimmune, and neurodegenerative disease that affects the central nervous system. Royal jelly (RJ), a nutrient-rich substance known for its anti-inflammatory and antioxidant properties, holds potential in impeding disease progression by mitigating inflammatory processes and oxidative stress. This study was undertaken to explore the impact of RJ on oxidative stress and inflammatory markers in individuals diagnosed with MS.

Methods:

This randomized clinical trial involved the allocation of 35 MS patients into two groups: intervention (n = 19) and control (n = 16). The intervention group received daily 500 mg RJ capsules for a duration of 2 months, while the control group received placebo capsules. Prior to and following the intervention, the Expanded Disability Status Scale (EDSS) was ascertained for the patients. Furthermore, the serum levels of inflammatory markers interleukin (IL-1B), IL-6, tumor necrosis factor (TNF), and interferon (IFN), in addition to the oxidative stress indices catalase (CAT), malondialdehyde (MDA), superoxide dismutase, and nitric oxide were evaluated. The data were analyzed using the GraphPad Prism software.

Results:

After the intervention, the mean EDSS score significantly decreased in the case group compared to pre-intervention (P < 0.05). Levels of MDA, IL-1B, TNF, and IFN significantly decreased in the case group post-intervention (P < 0.05). Additionally, a significant increase in CAT enzyme levels was observed in the case group after two months (P < 0.05). In contrast, the control group showed a significant increase in MDA levels after 2 months compared to baseline (P < 0.05).

Conclusion:

Our findings suggest that RJ supplementation may have beneficial effects on inflammatory markers, oxidative stress indices and quality of life in MS patients.

Introduction

Multiple sclerosis (MS) is a complex disease of the central nervous system (CNS) involving both inflammation and neurodegeneration^[1]. The cause of MS is not fully understood but is believed to be influenced by genetic and environmental factors^[2]. In MS, the central nervous system is invaded by inflammatory cells like lymphocytes, macrophages, and microglia, leading to the destruction of myelin, damage to nerve fibers, and impairment of neurological function^[3].

Highlights.

• Multiple sclerosis (MS) is a complex disease of the central nervous system (CNS) involving both inflammation and neurodegeneration.

• The disease is characterized by interconnected processes that worsen each other, including damage to blood vessels, long-term inflammation, and an imbalance in oxidative processes.

• A new treatment opportunity may involve targeting free radicals.

• Utilizing antioxidants and substances influencing antioxidant pathways can lessen disease severity, facilitate quicker recovery, and result in milder neuroinflammation and neurodegeneration progression.

• Royal jelly (RJ), a natural substance, is commonly utilized in alternative medicine for its healing benefits, such as its ability to fight cancer, reduce inflammation, and provide antioxidant effects.

MS is characterized by interconnected processes that worsen each other, including damage to blood vessels, long-term inflammation, and an imbalance in oxidative processes^[4]. Inflammation plays a crucial role in the progression of MS by driving a pathogenic cascade that leads to oxidative damage and mitochondrial injury, particularly in the progressive stages of the disease. Oxidative stress has also been linked to the development of demyelination in MS^[5,6].

The current treatment aims to decrease inflammation with some focus on preventing neurodegeneration. A new treatment opportunity may involve targeting free radicals. Utilizing antioxidants and substances influencing antioxidant pathways can lessen disease severity, facilitate quicker recovery, and result in milder neuroinflammation and neurodegeneration progression^[7,8].

Royal jelly (RJ), a natural substance, is commonly utilized in alternative medicine for its healing benefits, such as its ability to fight cancer, reduce inflammation, and provide antioxidant effects^[9]. The beneficial properties of RJ are attributed to its bioactive compounds, including fatty acids, proteins, peptides, and phenolic compounds such as flavonoids^[10]. Research has shown that RJ has the potential to improve health conditions associated with autoimmune diseases and inflammatory diseases^[11-14]. Studies on RJ have demonstrated its ability to reduce inflammation by lowering levels of inflammatory markers such as interleukin-6 (IL-6), C-reactive protein, and tumor necrosis factor (TNF-a) in both humans and animal models^[15,16].

Due to previous studies indicating the effects of oxidative stress and the intermediary pro-inflammatory role of IL-1 in the pathogenesis of MS, and on the other hand, the apparent antioxidant properties of RJ and the lack of research in this area, we decided to investigate the effect of consuming this substance on serum oxidative stress markers and IL-1 in patients with MS before and after its consumption.

Methods

Trial design

The current study is a randomized double-blind clinical trial and applied the Consolidated Standards of Reporting Trials (CONSORT) statement 2010. The patients with MS with relapsing-remitting or secondary progressive MS, aged 20-45, with an EDSS score of less than 6, and undergoing treatment with beta-interferon (IFN) drugs for a minimum of 6 months, were enrolled.

The study excluded patients with the following conditions or characteristics: anemia, chronic heart or lung diseases, diabetes, autoimmune diseases such as rheumatoid arthritis, systemic lupus erythematosus (SLE), or liver diseases, patients undergoing treatment with corticosteroids and adrenocorticotropic hormone (ACTH), use of supplements, history of asthma and allergies in the patient, occurrence of allergic reactions during the consumption of RJ capsules, new attack during the study period, patient’s withdrawal from the study, use of medication other than beta-IFN, and Expanded Disability Status Scale (EDSS) score higher than 6.

Baseline assessment

Eligible patients were interviewed by a neurologist to collect related information and complete questionnaires. Through a face-to-face interview, demographic variables of participants including age, gender, education, job and EDSS score were gathered.

Intervention

Each patient in the intervention group was given sixty 500-milligram capsules of RJ produced by Rudin Food Industries and was asked to consume one capsule daily for two months, half an hour before breakfast. Patients in the control group received a placebo drug with a similar size and shape to the RJ capsules and were asked to consume one 500-mg capsule daily for 2 months.

Biochemical parameters assessment

At the beginning of the study, a 5-ml blood sample was taken from patients in both groups, and the serum was separated and stored in a freezer at -70 degrees Celsius. The levels of the oxidative stress index (malondialdehyde; MDA) and the activity of antioxidant enzymes (superoxide dismutase [SOD] and catalase) and nitric oxide (NO) were measured using standard kits according to the manufacturer’s protocol.

After 2 months from the start of the study, the patients were re-evaluated by a specialist physician, and the overall EDSS level of all patients in both groups was determined. Additionally, blood samples were taken from the patients, and the levels of serum oxidative stress markers and NO were measured again.

Statistical methods

For data analysis, the Chi-square test and t-test were used. Data analysis was performed using GraphPad Prism software version 8, and P < 0.05 was considered statistically significant.

Results

In this study, the mean age of the study subjects was 35.95 ± 7.948 and 40.19 ± 8.968 years in the intervention and control groups, respectively. Table 1 shows the demographic data of the two groups. In addition, the results of EDSS in both groups are presented in Table 2. As shown in the table, the mean of MS patient’s EDSS which consumed RJ has been significantly lowered as compared with control group (P value = 0.0281).

Table 1.

Demographic and background information in two intervention and control groups

	Control group (n)	Case group (n)	P value
Gender
Male	–	4	0.029
Female	16	15
Marital status
Single	2	2	0.675
Married	13	16
Divorced	1	1
Education
Primary education	2	1	0.059
Secondary education	1	3
Diploma	7	6
BS	5	5
MS and higher	–	4
Job
Student	1	–	0.29
Employee	–	4
Unemployed	–	1
Housekeeping	14	10
Free	–	4

Table 2.

Results of patients’ EDSS of case and control groups

EDSS score	Control group	Case group
	Mean ± SD	Mean ± SD
Pre-treatment	3.563 ± 2.024	3.132 ± 2.241
Post-treatment	3.375 ± 1.987	2.921 ± 2.162
P value	0.0544	0.0281

Paired t-test analysis showed a statistically significant decrease in IL-1B and IL-6 level in intervention group (P value = 0.0005, P value = 0.0100 respectively). The levels of TNF and IFN also demonstrated a significant decrease after the intervention (P value = 0.0133, P value = 0.0106 respectively).

Additionally, a significant increase in catalase (CAT) enzyme levels was observed in the intervention group after intervention (P value = 0.0277). In intervention group NO level decreased significantly (P value = 0.0127). Paired t-test results demonstrated a statistically significant difference in MDA levels in both group before and after the intervention. The comparison between SOD levels was not statistically significant (P value> 0.05). The comparison of inflammatory markers and oxidative stress indices before and after intervention in the study groups are presented in Figures 1 and 2, respectively.

Figure 1.

Comparison of inflammatory markers before and after intervention in the study groups. * Indicates a significant difference (*P <0.05 and ** P < 0.002 ***P <0.0003).

Figure 2.

Comparison of oxidative stress indices before and after intervention in the study groups. * Indicates a significant difference (*P <0.05 and ** P < 0.002 ***P <0.0003).

Discussion

Inflammation and oxidative stress are closely related in MS, with inflammation promoting oxidative stress and vice versa, contributing to disease pathophysiology^[17]. Proinflammatory cytokines play a crucial role in the inflammatory, increase oxidative stress and promote neuroinflammation, leading to demyelination, axonal damage, and neuronal death in MS^[18,19].

Previous studies suggest that RJ can strengthen the immune system and be effective in improving neurodegenerative^[20] and autoimmune diseases, potentially contributing to the positive outcomes observed in MS patients^[21,22]. Oshvandi et al found that the use of RJ capsules significantly improved the daily activity status scores in MS patients^[23].

RJ treatment has been linked to a reduction in MDA levels and an increase in antioxidant enzyme activities, such as glutathione S-transferase (GST), glutathione peroxidase (GSH-Px), and SOD, supporting the antioxidant effects of RJ due to its amino acid content. RJ demonstrated a significant protective effect against liver and kidney damage induced by cisplatin (CDDP) treatment. It reduced lipid peroxidation levels, increased glutathione (GSH) levels, and enhanced the activities of antioxidant enzymes like GST, GSH-Px, SOD in the liver and kidneys^[24].

Another experimental investigation reported that the specific combination of exercise training and consumption of RJ at particular doses showed significant effectiveness in enhancing pain threshold levels and associated pathways in the experimental autoimmune encephalomyelitis (EAE) model of MS. This highlights the potential therapeutic benefits of RJ in managing symptoms of MS^[25]. Endurance training (ET) on positive and negative slopes, as well as RJ consumption, either alone or combined, demonstrated beneficial effects on motor balance improvement in rats with Alzheimer’s disease^[26].

RJ demonstrates potent antioxidant properties, protecting brain tissue from fluoride-induced damage. RJ enhances GSH levels and CAT activity while reducing MDA levels, indicating its antioxidant effects^[12]. explored how RJ protects against HDU-induced liver damage in rats through antioxidant, anti-inflammatory, and anti-apoptotic mechanisms.

RJ, particularly at a dose of 100 mg/kg, has shown effectiveness in improving mobility, reducing proinflammatory cytokine functions, and ameliorating demyelination in rats with MS-like behavior^[27].

A research by Chiang et al showed that RJ protein (RJP) hydrolysates, rich in bioactive compounds like 10-HDA, flavonoids, and phenolic acids, exhibit significant protective effects against DNA oxidative damage and LDL oxidation^[28]. By downregulating pathways like nuclear factor kappa B (NF-kB) and c-Jun N-terminal kinase (JNK), RJ indirectly influences cytokine production, leading to a decrease in inflammatory responses^[29]. RJ’s impact on immune system modulation, redox balance, oxidative stress, and antioxidant levels makes it a promising natural supplement for addressing the autoimmune, inflammatory, and oxidative stress-mediated aspects of MS^[30].

In summary, our study results demonstrate that the daily consumption of 500 mg RJ capsules by MS patients for 2 months led to a significant improvement in the EDSS score, accompanied by a significant reduction in lipid peroxidation and an increase in the activity of antioxidant enzymes CAT and SOD. Therefore, RJ can be recommended as a safe dietary supplement to minimize symptoms, improve the function of MS patients, and even prevent the progression of the disease.

Conclusion

The outcome of the present finding is that RJ may possess antioxidant, and anti-inflammatory activities and RJ supplementation to the dietary of MS patients may be effective.

Ethical approval

The present research project was approved by the Research Ethics Committee of Dezful University of Medical Sciences (IR.DUMS.REC.1401.076) and received IRCT approval code (IRCT20221002056071N1).

Consent

Written informed consent was obtained from the patient for publication and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal on request.

Sources of funding

This study was financially supported by grant (no.: 401040) from Vice-Chancellor for Education and Research Affairs of Dezful University of Medical Sciences.

Authors’ contribution

Z.E, S.S., and M.T participated in the design of the study. M.B, M.Z., and S.B. collected and analyzed the data. All authors participated in the manuscript writing and approved the final revision.

Conflicts of interest disclosure

The authors declare no competing interests

Guarantor

Dr Mahin Behzadifard

Research registration unique identifying number (UIN)

This research IRCT approval code is (IRCT20221002056071N1).

Provenance and peer review

Not applicable.

Data availability statement

The dataset generated and analyzed during the current study are not publicly available due to the ethics approval (but are available from the corresponding author on reasonable request).