Neuroprotective Effect of Protaetia brevitarsis seulensis' Water Extract on Trimethyltin-Induced Seizures and Hippocampal Neurodegeneration

Characterization and evaluation of actinomycete from the Protaetia brevitarsis Larva Frass

Protaetia brevitarsis larvae (PBL) are soil insects important for the soil organic carbon cycle, and PBL frass not only contains a large amount of humic acid but also affects the diversity, novelty, and potential functions of actinomycetes. Here, we characterized and assessed the actinomycete. The operational taxonomic unit (OTU) data showed that 90% of the actinomycetes cannot be annotated to species, and pure culture and genome analysis showed that 35% of the strains had the potential to be new species, indicating the novelty of PBL frass actinomycetes. Additionally, genome annotation showed that many gene clusters related to antifungal, antibacterial and insecticidal compound synthesis were identified, and confrontation culture confirmed the antifungal activities of the actinomycetes against soil-borne plant pathogenic fungi. The incubation experiment results showed that all isolates were able to thrive on media composed of straw powder and alkaline lignin. These results indicated that PBL hindgut-enriched actinomycetes could survive in soil by using the residual lignocellulose organic matter from plant residues, and the antibiotics produced not only give them a competitive advantage among soil microflora but also have a certain inhibitory effect on plant diseases and pests. This study suggests that the application of PBL frass can not only supplement soil humic acid but also potentially affect the soil microbiota of cultivated land, which is beneficial for the healthy growth of crops.

Fermented Protaetia brevitarsis Larvae Improves Neurotoxicity in Chronic Ethanol-Induced-Dementia Mice via Suppressing AKT and NF-κB Signaling Pathway

This study was investigated to examine the neuroprotective effect of fermented Protaetia brevitarsis larvae (FPB) in ethanol-induced-dementia mice. Consumption of FPB by mice resulted in improved memory dysfunction in the Y-maze, passive avoidance, and Morris water maze tests. FPB significantly decreased oxidative stress by regulating levels of malondialdehyde (MDA), superoxide dismutase (SOD), and reduced glutathione (GSH) in brain tissues. In addition, FPB restored cerebral mitochondrial dysfunction by modulating levels of reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and ATP. In addition, FPB enhanced the cholinergic system via the regulation of acetylcholine (ACh) content, acetylcholinesterase (AChE) activity, and expressions of AChE and choline acetyltransferase (ChAT) in brain tissues. FPB ameliorated neuronal apoptosis through modulation of the protein kinase B (AKT)/B-cell lymphoma (BCL)-2 signaling pathway. Also, FPB improved inflammation response by down-regulating the toll-like receptor (TLR)-4/nuclear factor (NF)-κB pathway. Additionally, FPB ameliorated synaptic plasticity via the increase of the expressions of synaptophysin (SYP), postsynaptic density protein (PSD)-95, and growth-associated protein (GAP)-43. Treatment with FPB also reinforced the blood-brain barrier by increasing tight junctions including zonula occludens (ZO)-1, occludin, and claudin-1. In conclusion, these results show that FPB can improve cognitive impairment via AKT/NF-κB pathways in ethanol-induced-dementia mice.

Chondroprotective effects of Protaetia brevitarsis seulensis larvae as an edible insect on osteoarthritis in mice

Osteoarthritis (OA) is a common chronic joint inflammatory disease characterized by progressive destruction of the articular cartilage, bone remodeling, and excessive chronic pain. Most therapeutic approaches do not rescue the progression of OA effectively or provide relief of symptoms. Protaetia brevitarsis seulensis larva (PBSL), which is attracting attention, is an edible insect with very high nutritional value and herbal medicine for the treatment of blood stasis, hepatic disease, and various inflammatory diseases. However, the effect of PBSL on OA has not yet been investigated. This study aimed to demonstrate the effects of PBSL water extract on the progression of OA using monosodium iodoacetate (MIA)-induced mice and SW1353 chondrocytes or murine macrophages. We injected MIA into the intraarticular area of mice following pretreatment with either saline or PBSL (200 mg/kg) for 2 weeks, and then locomotor activity, microcomputed tomography and histopathological analysis, quantitative reverse transcriptase-polymerase chain reaction analysis, and western blot analysis were performed. To determine the molecular effects of PBSL, we used interleukin-1β (IL-1β)-induced SW1353 chondrosarcoma or lipopolysaccharide (LPS)-stimulated macrophages. Pretreatment with PBSL diminished the symptoms of OA. Physical activity, articular cartilage damage, and the generation of microfractures were rescued by pretreatment with PBSL in the mouse model. Pretreatment with PBSL suppressed the progress of OA through the regulation of articular cartilage degradation genes and inflammation in both in vivo and in vitro models. Our results demonstrated that PBSL has value as edible insect that can be used in the development of functional foods for OA.

Plasma neurofilament light chain as a potential biomarker of neurodegeneration in murine brain

Reliable fluid biomarkers for evaluating neurotoxicity have yet to be established. However, recent studies have reported neurofilament light chain as a fluid biomarker of several neurodegenerative disorders. In this study, we investigated changes in the cerebrospinal fluid and plasma levels of neurofilament light chain in mice treated with trimethyltin as a neurotoxicant. Trimethyltin diluted with saline was administered by intraperitoneal injection to mice at dose levels of 0 (vehicle control), 1.0, and 2.6 mg/kg body weight (dosage volume: 10 mL/kg). At 3 or 7 days after administration, animals were euthanized by exsanguination under 2-3% isoflurane inhalation anesthesia. Increased neurofilament light chain levels in both the cerebrospinal fluid and plasma were observed in animals from the trimethyltin 2.6 mg/kg body weight group, which indicated the brain lesions including neuronal cell death. Animals from the trimethyltin 1.0 mg/kg body weight group exhibited changes neither in neurofilament light chain levels in the cerebrospinal fluid and plasma nor in the histopathology of the brain at any time point. These data indicate that plasma neurofilament light chain can serve as a useful peripheral biomarker for detecting brain lesions such as neuronal necrosis in mice.

Protaetia brevitarsis seulensis larvae ethanol extract inhibits RANKL-stimulated osteoclastogenesis and ameliorates bone loss in ovariectomized mice

Modulation of osteoclast formation could be a therapeutic target for inhibiting pathological bone destruction. The receptor activator of nuclear factor (NF)-κB ligand (RANKL) is known to be an essential factor in osteoclast differentiation and activation inducers. However, whether Protaetia brevitarsis seulensis (P. brevitarsis) larvae-a traditional animal-derived medicine used in many Asian countries-can inhibit RANKL-induced osteoclast formation and prevent ovariectomy (OVX)-induced bone loss has not been evaluated. Here, we aimed to investigate the anti-osteoporotic effects of P. brevitarsis larvae ethanol extract (PBE) in RANKL-stimulated RAW264.7 cells and OVX mice. In vitro, PBE (0.1, 0.5, 1, and 2 mg/mL) decreased RANKL‑induced tartrate-resistant acid phosphatase (TRAP) activity and expression of osteoclastogenesis-associated genes and proteins. Furthermore, PBE (0.1, 0.5, 1, and 2 mg/mL) significantly inhibited the phosphorylation of p38 and NF-κB. Female C3H/HeN mice were divided into five groups (n = 5 per group), namely, sham-operated, OVX, OVX+PBEL (100 mg/kg, oral gavage), OVX+PBEH (200 mg/kg, oral gavage), and OVX+estradiol (0.03 μg/day, subcutaneous injection). High doses of PBE significantly increased femoral bone mineral density (BMD) and bone volume/tissue volume (BV/TV), whereas femoral bone surface/bone volume (BS/BV) and osteoclastogenesis-associated protein expression decreased compared to those in the OVX group. Moreover, PBE (200 mg/kg) significantly increased estradiol and procollagen type I N-terminal propeptide and decreased N-terminal telopeptide of type I collagen and C-terminal telopeptide of type I collagen compared to those in the OVX group. Our results suggest that PBE can be an effective therapeutic candidate for preventing or treating postmenopausal osteoporosis.

Microflora for improving the Auricularia auricula spent mushroom substrate for Protaetia brevitarsis production

Mushroom cultivation is a sustainable agricultural waste utilization method, but the lack of high-value utilization of the produced spent mushroom substrate (SMS) has hindered the development of mushroom cultivation-based circular agricultural systems. Conversion and utilization of SMS via Protaetia brevitarsis larvae (PBL) have proven to be a high-value AASMS utilization strategy. However, Auricularia auricula SMS (AASMS), which contains woodchips, is less palatable and digestible for PBL. To solve this problem, in this investigation, we screened out microflora (MF) for AASMS fermentation by comparing the fermentation performance as well as the effect on PBL feed intake, weight gain, and AASMS phytotoxic compound removal efficiency. In addition, by bacterial community analysis, the genera Luteimonas, Moheibacter, and Pseudoxanthomonas were predicted to be functional bacteria for AASMS fermentation and contribute to palatability and digestibility improvement.

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Larvae frass microflora can ferment Auricularia auricula spent mushroom substrate

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The fermentation can improve feed intake, weight gain, and phytotoxic removal efficiency

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The genera Luteimonas, Moheibacter, and Pseudoxanthomonas were functional bacteria

Neuroprotective effect of Geijigadaehwang-tang against trimethyltin-induced hippocampal neurodegeneration: An in vitro and in vivo study

ETHNOPHARMACOLOGICAL RELEVANCE

Patients with dementia are diagnosed with deficiency patterns and interior patterns in traditional Chinese medicine due to decreased physical strength, mental atrophy including cognitive function, and decreased motor function in the gastrointestinal tract. Since "greater yin symptom" in Shanghanlun has been interpreted as interior, deficiency, and cold pattern in traditional Chinese medicine, it is necessary to determine whether Geijigadaehwang-tang (GDT) has therapeutic effects on neurodegenerative diseases and the underlying mechanism if it has such effects.

AIMS OF THE STUDY

Trimethyltin (TMT), a neurotoxic organotin compound, has been used to induce several neurodegenerative diseases, including epilepsy and Alzheimer's disease. This study aimed to evaluate the therapeutic efficacy of GDT for TMT-induced hippocampal neurodegeneration and seizures and to determine the mechanisms involved at the molecular level.

MATERIALS AND METHODS

The main components of GDT were analyzed using ultra-performance liquid chromatography. TMT was used to induce neurotoxicity in microglial BV-2 cells and C57BL6 mice. GDT was administered at various doses to determine its neuroprotective and seizure inhibition effects. The inhibitory effects of GDT on TMT-induced apoptosis, inflammatory pathways, and oxidative stress pathways were determined in the mouse hippocampal tissues.

RESULTS

GDT contained emodin, chrysophanol, albiflorin, paeoniflorin, 6-gingerol, and liquiritin apioside. In microglial BV-2 cells treated with TMT, GDT showed dose-dependent neuroprotective effects. Oral administration of GDT five times for 2.5 days before and after TMT injection inhibited seizures at doses of 180 and 540 mg/kg and inhibited neuronal death in the hippocampus. In hippocampal tissues extracted from mice, GDT inhibited the protein expression of ionized calcium binding adaptor molecule 1, glial fibrillary acidic protein, nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3, and phosphorylated nuclear factor (NF)-κB/total-NFκB ratio. Additionally, GDT inhibited the messenger RNA levels of tumor necrosis factor-α, inducible nitric oxide synthase, apoptosis-associated speck-like protein containing a caspase recruitment domain, caspase-1, interleukin-1β, nuclear factor erythroid-2-related factor 2, and heme oxygenase-1.

CONCLUSION

This study's results imply that GDT might have neuroprotective potential in neurodegenerative diseases through neuronal death inhibition and anti-inflammatory and antioxidant mechanisms.

Protective effects of an aqueous extract of Protaetia brevitarsis seulensis larvae against radiation‐induced testicular injury in mice

The larvae of Protaetia brevitarsis seulensis have been used as a food ingredient and are known for their nutritional value and anti‐inflammatory properties. However, whether P. brevitarsis seulensis larvae demonstrate protective effects against radiation‐induced testicular injury has not been investigated. In this study, the protective effects of an aqueous extract of P. brevitarsis seulensis larvae (PBE) against radiation‐induced testicular injury were tested. Male C57BL/6 mice were administered PBE (5 or 10 mg/kg) orally for 14 days before exposure to focal pelvic irradiation. Histopathological examinations were conducted at 8 h and 30 d after radiation exposure. PBE pretreatment reduced the radiation‐induced apoptosis of germ cells at 8 h after irradiation and significantly increased testis and epididymis weights relative to those of the irradiated control mice at 30 days. PBE protected against histopathological damage and decreased the radiation‐induced effects on the epithelium height and seminiferous tubule diameter. Furthermore, the extract ameliorated the radiation‐induced morphological abnormalities of sperm cells and improved their motility. It also prevented a decrease in the epididymal sperm count caused by irradiation. Moreover, the extract alleviated the generation of reactive oxygen species, and its antioxidative activity increased in a dose‐dependent manner. Among the six major compounds isolated from PBE, benzoic acid and uridine showed the highest antioxidant activities. These results suggest that PBE protects against radiation‐induced testicular injury via its antioxidative properties. Thus, it has potential clinical applicability as a neoadjuvant therapy for the prevention of testicular damage caused by cancer radiotherapy.

Characterization of Microorganisms from Protaetia brevitarsis Larva Frass

Decomposers play an important role in the biogeochemical cycle. Protaetia brevitarsis larvae (PBLs) can transform wastes into frass rich in humic acid (HA) and microorganisms, which may increase the disease resistance of plants and promote plant growth. Beyond HA, the microorganisms may also contribute to the biostimulant activity. To address this hypothesis, we investigated the potential microbial community in the PBL frass samples and elucidated their functions of disease resistance and plant growth promotion. High-throughput sequencing analysis of four PBL-relevant samples showed that their frass can influence the microbial community of the surrounding environment. Further analysis showed that there were many microorganisms beneficial to agriculture, such as Bacillus. Therefore, culturable Bacillus microbes were isolated from frass, and 16S rDNA gene analysis showed that Bacillus subtilis was the dominant species. In addition, some Bacillus microorganisms isolated from the PBL frass had antibacterial activities against pathogenic fungi. The plant growth promotion pot experiment also proved that some strains promote plant growth. In conclusion, this study demonstrated that the microorganisms in the PBL frass are conducive to colonizing the surrounding organic matrix, which will help beneficial microbes to increase the disease resistance of plants and promote plant growth.

Effects of larval extracts from identified Protaetia brevitarsis seulensis against benign prostatic hyperplasia induced by testosterone in rats

Protaetia brevitarsis seulensis is an animal-based medicine used traditionally in China, Japan, and Korea to treat hepatic disorders; it has been shown to possess various pharmacological effects such as antibacterial and antioxidant activities. In this study, we investigated the effects of P. brevitarsis on a testosterone-induced benign prostatic hyperplasia (BPH) rat model. To establish the BPH model, the animals were administered a subcutaneous injection of testosterone daily for 28 days. P. brevitarsis was administered by oral gavage at doses of 12.5, 25, and 50 mg/kg for 28 days, along with testosterone injection. P. brevitarsis treatment markedly decreased the absolute and relative prostate weight of BPH animals. The levels of dihydrotestosterone was reduced in P. brevitarsis-treated animals compared to those in the BPH animals. Histological analysis of the prostate showed that P. brevitarsis treatment effectively suppressed the testosterone-induced hyperplasia of prostatic epithelial cells, which was accompanied by reductions in the PCNA and Ki-67 expressions in prostatic tissues. These results indicate that P. brevitarsis effectively suppresses testosterone-induced development of BPH, and thus, is a potential therapeutic agent for BPH.