Inflammatory Regulation Effect and Action Mechanism of Anti-Inflammatory Effective Parts of Housefly (Musca domestica) Larvae on Atherosclerosis

Response Surface Methodology (RSM) for Optimizing Protein Extraction from Housefly (Musca domestica) Larvae Fed with Toad and Its Structural Characterization

With the global population on the rise, an escalating interest exists in environmentally sustainable and friendly protein sources. Insects have emerged as multifaceted resources, viewed not only as potential food items, but also as sources of traditional medicines and proteins. This study utilized response surface methodology (RSM) to ascertain the optimal extraction conditions for proteins from Musca domestica used in toad feeding, denoted as MDPs-T. The yield of MDPs-T was elevated to 18.3% ± 0.2% under these optimized conditions. Subsequently, the particle size, ζ-potentials, and structures of MDPs-T were analyzed and compared with the proteins derived from Musca domestica fed on a normal diet (MDPs-ND). This comparative analysis utilized a range of advanced techniques, involving UV spectroscopy, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), high-performance gel permeation chromatography (HPGPC), and scanning electron microscopy (SEM). The outcomes have revealed a marginal disparity in the physical and chemical properties between MDPs-T and MDPs-ND. Derosination led to a reduction in the particle size of the MDPs by 10.98% to 62.81%. MDPs-T exhibited a higher proportion of low-molecular-weight components relative to MDPs-ND. Additionally, in a comparative analysis of amino acids, MDPs-T displayed a greater abundance of essential and total amino acids relative to MDPs-ND. Consequently, MDPs-T holds potential as a valuable food supplement for human consumption or as a nutrient-rich feed supplement for animals.

Comparison of the antioxidant activities of nonfumigated and sulphur-fumigated Chrysanthemum morifolium cv. Hang-ju induced by oxidative stress

CONTEXT

The traditional drying method, sun drying, for Chrysanthemum morifolium Ramat. cv. Hang-ju (Compositae) (HJ) is widely replaced by sulphur fumigation (SF), which has an unknown effect on its efficacy.

OBJECTIVE

To investigate protective effects of nonfumigated HJ (NHJ) and sulphur-fumigated HJ (SHJ) water extracts against oxidative stress and lipid peroxidation.

MATERIALS AND METHODS

Sprague-Dawley rats were administered high-fat diet to induce hyperlipidaemia and randomly divided into eight groups (n = 6): control, fenofibrate, NHJ and SHJ extracts (1, 2 or 4 g crude drugs/kg/d; intragastric administration for 8 weeks). Serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), superoxide dismutase (SOD) and malondialdehyde (MDA) levels were detected. Human umbilical vein endothelial cells (HUVECs) were treated with NHJ and SHJ extracts (50, 100 or 200 μg/mL) for 24 h, followed by oxidized low-density lipoprotein (ox-LDL, 20 μg/mL) for 2 h in vitro. Cellular reactive oxygen species (ROS), SOD and MDA levels and apoptosis were evaluated.

RESULTS

NHJ was more effective than SHJ in decreasing serum TG, TC, LDL-C, LDL/HDL and MDA while increasing serum HDL-C and SOD levels at high doses. SHJ (IC₅₀=19.9 mg/mL) suppressed HUVEC growth stronger than NHJ (IC₅₀=186.7 mg/mL). At 200 μg/mL, NHJ was more effective than SHJ in downregulating ROS and MDA levels, reducing HUVECs apoptosis rate and elevating SOD activity in ox-LDL-treated HUVECs.

CONCLUSIONS

SF causes oxidative damage and attenuates antioxidative activity in ox-LDL-treated HUVECs, which promotes lipid peroxidation. SF is not recommended for processing HJ.

Enhanced Antioxidant and Cytotoxic Potentials of Lipopolysaccharides-Injected Musca domestica Larvae

The usage of insects as a sustainable and functional natural products resource is a new promise in complementary and alternative medicine. The present study aimed to investigate the ability of Musca domestica (housefly) larval hemolymph (insect blood) to display the enhanced in vitro antioxidant and cytotoxic effects. The oxidative stress (OS) was elicited by inducing lipopolysaccharides (LPS) treatment as an exogenous stressor. Determination of superoxide dismutase 1 (SOD1), glutathione (GSH), malondialdehyde (MDA) and total antioxidant capacity (TAC), and mRNA and protein expressions of SOD1, was investigated as confirmatory markers of oxidative stress induction. Cytotoxicity on cancerous MCF-7 and normal Vero cells were also evaluated using an MTT assay at 24 h post-injection. The injection of LPS induced a significant (p < 0.05) increase in SOD, GSH and TAC, whereas, the MDA was diminished. Hemolymph was collected from normal and treated larvae after 6, 12 and 24 h. The M. domestica superoxide dismutase (MdSOD1) transcripts were significantly (p < 0.05) upregulated 6 and 12 h post-treatment, while a significant downregulation was observed after 24 h. Western blot analysis showed that MdSOD1 was expressed in the hemolymph of the treated larvae with an increase of 1.2 folds at 6 and 12 h and 1.6 folds at 24 h relative to the control group. LPS-treated larval hemolymphs exhibited significant cytotoxicity with respect to the untreated ones against MCF-7 while Vero cells showed no cytotoxicity for both hemolymphs. The DPPH free radical scavenging activity was examined and a significant antioxidant potential potency was observed at 6 h (50% maximal inhibitory concentration (IC50): 63.3 ± 3.51 µg/mL) when compared to the control M. domestica larval hemolymph (IC50: 611.7 ± 10.41 µg/mL). Taken together, M. domestica larval hemolymph exhibited enhanced antioxidant and consequently increased cytotoxic capacities under stressed conditions.

Dietary Supplementation with Housefly (Musca domestica) Maggot Meal in Growing Beagles: Hematology, Serum Biochemistry, Immune Responses and Oxidative Damage

The present study was carried out to evaluate the hematology, serum biochemistry, immune responses and oxidative damage of growing beagles fed a diet supplemented with housefly (Musca domestica) maggot meal (MM). Weanling beagles (initial body weight 2.69 ± 0.17 kg) were fed a control diet (0% MM) or experimental diet (5% MM) for 42 days. The results indicated that the diet supplemented with 5% MM had no significant effects on the hematology and serum biochemistry of growing beagles (P>0.05). Meanwhile, neither the serum concentrations of lysozyme and C-reactive protein nor the serum antibody responses to canine distemper virus and canine parvovirus were influenced by dietary MM supplementation (P>0.05). However, dogs in the experimental group had lower serum levels of malondialdehyde and protein carbonyl than those in the control group (P<0.05). These findings demonstrated that MM could be used as an alternative protein source in growing beagles without any adverse effects on hematology, serum biochemistry and immune responses. Furthermore, dietary MM could alleviate oxidative damage in growing beagles.

Protein-rich extract of Musca domestica larvae alleviated metabolic disorder in STZ-induced type 2 diabetic rat model via hepatoprotective and pancreatic β-cell protective activities

The study was designed to explore the beneficial effect of Musca domestica larvae extract (MDLE) on a metabolic disorder using a diabetic rat model. Streptozotocin-induced diabetic rats were treated with or without MDLE. Blood glucose, insulin levels, lipid profiles, and oxidative stress markers were measured. The morphological changes in the pancreas and liver were determined, as well as insulin expression. The expression of glucose transporter 4 (GLUT4), phospho-adenosine monophosphate-activated protein kinase (p-AMPK)/total AMPK, superoxide dismutase 1 (SOD1), catalase (CAT), and peroxisome proliferator-activated receptor gamma (PPARγ) were detected. Compared with untreated diabetic rats, MDLEtreated rats had decreased urine volume, food intake, and water intake, along with significantly lower levels of blood glucose, malondialdehyde (MDA), plasma triglycerides, low-density lipoprotein (LDL), and total cholesterol. MDLEtreated rats also had higher levels of SOD activity, high-density lipoprotein (HDL), and insulin. MDLE treatment partially restored the β-cell population, improved the liver necrosis and islet cell damage, reversed the decreased expression of GLUT4, phospho-AMPK, SOD1, and CAT in the liver, skeletal muscle and pancreatic tissue, and also increased the expression of PPARγ in the liver and adipose tissue in diabetic rats. In conclusion, the obtained results suggest that MDLE could possibly be used pharmacologically as an adjuvant for the treatment of diabetes.

Immunological adjuvant effect of the peptide fraction from the larvae of Musca domestica

BACKGROUND

The larvae of Musca domestica (Diptera: Muscidae) have been used traditionally for malnutritional stagnation, decubital necrosis, osteomyelitis, ecthyma and lip scald and also to treat coma and gastric cancer in the traditional Chinese medicine. Its immunomodulatory effects in naïve mice in relation to the traditional uses were also reported. However, the immunological adjuvant potentials of this insect have not yet been studied.

METHODS

The peptide fraction from the larvae of Musca domestica L. (MDPF) was evaluated for its adjuvant potentials on the immune responses to ovalbumin (OVA) and avian influenza vaccine (rL-H5) by determining antigen-specific antibody titers, splenocyte proliferation, activity of natural killer (NK) cell, the secretion of cytokines from splenocytes in the immunized mice.

RESULTS

MDPF significantly enhanced not only the concanavalin A (Con A)-, lipopolysaccharide (LPS)- and antigen-stimulated splenocyte proliferation, but serum antigen-specific IgG, IgG1, IgG2a, and IgG2b antibody titers in the mice immunized with OVA and rL-H5. MDPF also remarkably promoted the killing activities of NK cells in splenocytes from the mice immunized with rL-H5. Furthermore, MDPF significantly promoted the production of Th1 (IL-2 and IFN-γ) and Th2 (IL-10) cytokines from splenocytes in the immunized mice.

CONCLUSIONS

The results indicated that MDPF had a potential to increase both cellular and humoral immune responses and elicit a balanced Th1/Th2 response, and that MDPF may be a safe and efficacious vaccine adjuvant candidate.

Antihepatitis B virus activity of a protein-enriched fraction from housefly (Musca domestica) in a stable HBV-producing cell line

Hepatitis B virus (HBV) infection remains a major public health problem. Although several vaccines and therapeutic strategies are currently being implemented to combat HBV virus, effective antiviral therapy against HBV infection has not been fully developed. Alternative strategies and new drugs to combat this disease are urged. Insects and insect derivatives are a large and unexploited source of potentially useful compounds for modern medicine. In the present study, we investigated the first anti-HBV activity of a protein-enriched fraction (PE) from the larvae of the housefly (Musca domestica) in a stable HBV-producing cell line. HBsAg and HBeAg in the culture medium were measured by enzyme-linked immunosorbent assay. HBV-DNA was quantified by fluorescent quantification PCR. HBV core protein was assayed by immunofluorescent staining. Results indicate PE treatment inhibited both HBsAg, HBeAg secretion, and HBV-DNA replication. Furthermore, PE could also suppress HBV core protein expression. PE could be a potential candidate for the development of a novel and effective drug for the treatment of HBV infection.

Anti-tumor and immunomodulatory activity of peptide fraction from the larvae of Musca domestica

ETHNOPHARMACOLOGICAL RELEVANCE

The larvae of Musca domestica (Diptera: Muscidae) have been used traditionally for malnutritional stagnation, decubital necrosis, osteomyelitis, ecthyma and lip scald and also to treat coma and gastric cancer in the traditional Chinese medicine. Its in vitro antitumor activity and immunomodulatory effect in naïve mice in relation to the traditional uses were also reported. However, the in vivo antitumor effect of this insect and its mechanism of action have not yet been well studied. The objectives of this study were to evaluate the in vivo antitumor potential of the peptide fraction from Musca domestica larvae (MDPF) and to elucidate its immunological mechanisms.

MATERIALS AND METHODS

The mice inoculated with sarcoma S180 cells were orally administered with MDPF at three doses for 10 days. The effects of MDPF on the growth of mouse S180 sarcoma, splenocyte proliferation, the activity of natural killer (NK) cells and cytotoxic T lymphocytes (CTLs), production and mRNA expression of cytokines from splenocytes, and serum antigen-specific antibody levels in tumor-bearing mice were measured.

RESULTS

MDPF could significantly not only inhibit the growth of mouse transplanted S180 sarcoma, but also promote splenocytes proliferation, NK cell and CTL activity from splenocytes, and enhance serum antigen-specific IgG, IgG2a and IgG2b antibody levels in S180-bearing mice. MDPF also significantly promoted the production of IFN-γ and up-regulated the mRNA expression levels of IFN-γ and Th1 transcription factors T-bet and STAT-4 in splenocytes from the S180-bearing mice. However, Th2 cytokine IL-10 and transcription factors GATA-3 and STAT-6 were not significantly changed both at transcriptional and protein levels following MDPF treatment.

CONCLUSIONS

MDPF significantly inhibit the growth of transplantable tumor in mice and its in vivo antitumor activity might be achieved by switching-on of Th1-based protective cell-mediated immunity. MDPF could act as antitumor agent with immunomodulatory activity.