Fatty acid extracts from Lucilia sericata larvae promote murine cutaneous wound healing by angiogenic activity

Protective effects of the bioactive peptide from maggots against skin flap ischemia‒reperfusion injury in rats

Ischemia‒reperfusion (I/R) injury is a frequently observed complication after flap surgery, and it affects skin flap survival and patient prognosis. Currently, there are no proven safe and effective treatment options to treat skin flap I/R injury. Herein, the potential efficacies of the bioactive peptide from maggots (BPM), as well as its underlying mechanisms, were explored in a rat model of skin flap I/R injury and LPS- or H2O2-elicited RAW 264.7 cells. We demonstrated that BPM significantly ameliorated the area of flap survival, and histological changes in skin tissue in vivo. Furthermore, BPM could markedly restore or enhance Nrf2 and HO-1 levels, and suppress the expression of pro-inflammatory cytokines, including TLR4, p-IκB, NFκB p65, p-p65, IL-6, and TNF-α in I/R-injured skin flaps. In addition, BPM treatment exhibited excellent biocompatibility with an adequate safety profile, while it exhibited superior ROS-scavenging ability and the upregulation of antioxidant enzymes in vitro. Mechanistically, the above benefits related to BPM involved the activation of Nrf2/HO-1 and suppression of TLR4/NF-κB pathway. Taken together, this study may provide a scientific basis for the potential therapeutic effect of BPM in the prevention of skin flap I/R injury and other related diseases.

Wound healing potential of Cystoseira/mesenchymal stem cells in immunosuppressed rats supported by overwhelming immuno-inflammatory crosstalk

Wound healing, one of the most intricate and dynamic processes of the body, maintains skin integrity following trauma. One of the main issues that still exists is impaired wound healing, particularly for immunosuppressed patients. Recently, natural products from marine environments have been employed in wound-repairing activities. This work investigates the mesenchymal stem cells in the combined capacity of the bone marrow (BMMSC) for wound healing and Cystoseira sp. Algae extract in immunosuppressed rats. High-resolution liquid chromatography / MS investigation of Cystoseira extract revealed the prevalence of fatty acids that have wound-soothing potential. From constructed PPI network for wound healing and further analysis through molecular docking and molecular dynamics (MD) simulation experiments suggested that cystalgerone metabolite may be responsible for the wound healing-promoting effect of Cystoseira extract. According to the CD marker characterization of the BMMSC, 98.21% of them expressed CD90, and 97.1% expressed CD105. Sixteen d after immunity suppression (by 40 mg/kg hydrocortisone daily), an incision was made in the dorsal skin of the rat. The treatments were applied for 16 d and samples were taken from the tested groups on the 8th, 14th, and 16th days. The BMMSCs / Cystoseira group showed significantly improved wound closure, thickness, density of new layers, and skin elasticity than the control group (p < 0.001). The BMMSCs / Cystoseira combination significantly reduced the oxidative indicators, pro-inflammatory cytokines, and immune markers, according to the RT-PCR gene expression study. In order to delve deeper into the complex interconnections among wound healing-related biological targets and pinpoint key factors in this complex process, we engaged in network pharmacology and computational research. Subsequently, we conducted a comprehensive computational analysis, including reverse docking, free energy (ΔG) computation, and molecular dynamics simulations, on the molecular structures of the annotated compounds. The purpose of this investigation was to identify potential new targets for these chemicals as well as any potential interactions they may have with different signaling pathways related to the wound healing process. Our research indicates that the primary compounds of Cystoseira holds potential wound healing therapeutic activity. Although more safety testing and clinical studies are required, the combination has great potential for regenerative medicine and could be a revolutionary advance in the healing of the wounds of immunosuppressed patients.

Ephedra alte extracts' GC-MS profiles and antimicrobial activity against multidrug-resistant pathogens (MRSA)

The extracts of E. alte offer promising potential as renewable resources for various chemical derivative products aimed at addressing antibiotic resistance. These extracts exhibited significant activity against methicillin-resistant Staphylococcus aureus (MRSA), a strain known for its resistance to multiple antibiotics. The extracts were found to be effective against several common antibiotics, including Imipenem, Ampicillin, Penicillin G, Oxacillin, and Amoxicillin-clavulanate. GC-MS analysis revealed that the phytoconstituents of E. alte extracts, obtained using both methanol and ethyl acetate, consist of a diverse range of 83 and 160 phytocompounds, respectively. These organic compounds serve as important biochemical precursors for the synthesis of vitamins E and K1, and exhibit antioxidant, antimicrobial, and anti-inflammatory properties in both plants and microorganisms. Notable compounds identified include fatty acids (such as palmitic acid, dodecanoic acid, sebacic acid, pentadecanoic acid, myristic acid, stearic acid, behenic acid, and linoelaidic acid), phytosterols (Campesterol, β-sitosterol, Stigmast-5-ene), sugars (D-fructose, Fructofuranans), terpenoids (Phytol, citronellol), and phenolic acids (Protocatechoic acid, shikimic acid). The antimicrobial activity of all E. alte extracts was found to be superior to that of mupirocin and ciprofloxacin, as observed in susceptibility testing against MRSA ATCC 43300 and other pathogenic bacteria and fungi. It is likely that the combined action of the antimicrobial components within the E. alte extract bypasses the mechanisms employed by MRSA to protect itself from antibiotics. Further experiments are needed to investigate the individual effects of each pure compound and their potential synergistic interactions, which may enhance their overall performance.

Metabolic reprogramming in skin wound healing

Metabolic reprogramming refers to the ability of a cell to alter its metabolism in response to different stimuli and forms of pressure. It helps cells resist external stress and provides them with new functions. Skin wound healing involves the metabolic reprogramming of nutrients, such as glucose, lipids, and amino acids, which play vital roles in the proliferation, differentiation, and migration of multiple cell types. During the glucose metabolic process in wounds, glucose transporters and key enzymes cause elevated metabolite levels. Glucose-mediated oxidative stress drives the proinflammatory response and promotes wound healing. Reprogramming lipid metabolism increases the number of fibroblasts and decreases the number of macrophages. It enhances local neovascularization and improves fibrin stability to promote extracellular matrix remodelling, accelerates wound healing, and reduces scar formation. Reprogramming amino acid metabolism affects wound re-epithelialization, collagen deposition, and angiogenesis. However, comprehensive reviews on the role of metabolic reprogramming in skin wound healing are lacking. Therefore, we have systematically reviewed the metabolic reprogramming of glucose, lipids, and amino acids during skin wound healing. Notably, we identified their targets with potential therapeutic value and elucidated their mechanisms of action.

Lipids Fraction from Caralluma europaea (Guss.): MicroTOF and HPLC Analyses and Exploration of Its Antioxidant, Cytotoxic, Anti-Inflammatory, and Wound Healing Effects

Caralluma europaea is a medicinal plant used in Morocco to cure a variety of illnesses. This study was conducted to determine the chemical composition, the antioxidant, antiproliferative, anti-inflammatory, and wound healing activities of C. europaea lipids. The chemical composition of C. europaea was analyzed using time-of-flight mass spectrometry and high-performance liquid chromatography. The antioxidant potential was determined using the 2,2-di-phenyl-1-picryl hydrazyl (DPPH), and ferric reducing antioxidant power (FRAP) tests. The antiproliferative effect was evaluated by MTT assay against HL60, K562, Huh-7 cancer cells, and normal Vero cells. The anti-inflammatory potential was conducted against carrageenan-induced paw edema. The wound healing effect was evaluated against skin burns for 21 days. The identified phytochemical compounds were docked for their effect on nicotinamide adenine dinucleotide phosphate oxidase, caspase-3, lipoxygenase, glycogen synthase kinase-3-β, and protein casein kinase-1. The results showed the presence of some lipids, such as linoleic acid and vitamin D3. The DPPH (IC50 = 0.018 mg/mL) and FRAP (EC50 = 0.084 mg/mL) of C. europaea lipids showed an important antioxidant effect. For the anti-inflammatory test, an inhibition of 83.50% was recorded after 6 h of treatment. Our extract showed the greatest wound retraction on the 21st day (98.20%). C. europaea lipids showed a remarkable antitumoral effect against the K562 cell line (IC50 = 37.30 µg/mL), with no effect on Vero cells (IC50 > 100 µg/mL). Lignoceric acid was the most active molecule against caspase-3 (−6.453 kcal/mol). The findings indicate the growing evidence of C. europaea as a potential treatment for several diseases.

Larval Therapy and Larval Excretions/Secretions: A Potential Treatment for Biofilm in Chronic Wounds? A Systematic Review

Chronic wounds present a global healthcare challenge and are increasing in prevalence, with bacterial biofilms being the primary roadblock to healing in most cases. A systematic review of the to-date knowledge on larval therapy's interaction with chronic-wound biofilm is presented here. The findings detail how larval therapy-the controlled application of necrophagous blowfly larvae-acts on biofilms produced by chronic-wound-relevant bacteria through their principle pharmacological mode of action: the secretion and excretion of biologically active substances into the wound bed. A total of 12 inclusion-criteria-meeting publications were identified following the application of a PRISMA-guided methodology for a systematic review. The findings of these publications were qualitatively analyzed to provide a summary of the prevailing understanding of larval therapy's effects on bacterial biofilm. A further review assessed the quality of the existing evidence to identify knowledge gaps and suggest ways these may be bridged. In summary, larval therapy has a seemingly unarguable ability to inhibit and degrade bacterial biofilms associated with impaired wound healing. However, further research is needed to clarify and standardize the methodological approach in this area of investigation. Such research may lead to the clinical application of larval therapy or derivative treatments for the management of chronic-wound biofilms and improve patient healing outcomes at a time when alternative therapies are desperately needed.

Anti-inflammatory and wound healing potential of medicinal maggot excretions/secretions at the ocular surface

PURPOSE

In the skin, Lucilia sericata maggot excretions/secretions (ES) accelerate wound healing and limit inflammation. This study aimed to determine whether ES have similar beneficial effects at the ocular surface.

METHODS

Human corneal epithelial cells (HCEC) were cultured with ES and cell viability was determined by the MTT assay. Additionally, mRNA expression of growth factors, antimicrobial peptides (AMPs) and cytokines was assessed by qPCR. ES ability to modulate TLR-induced IL-6 and IL-8 expression was determined by qPCR and ELISA. ES potential to promote corneal healing was evaluated in vitro by a migration assay in HCEC, and in vivo using a mouse model.

RESULTS

ES did not impair HCEC viability up to 25 μg/ml. Among the factors evaluated, only hBD-2 was upregulated (2.5-fold) by 1.5 μg/ml ES after 6 hrs (P = 0.04). In HCEC, ES reduced Poly I:C-induced IL-6 and IL-8 mRNA (P ≤ 0.001) and protein (P ≤ 0.0001) expression. A similar effect was observed with Flagellin (TLR5 agonist) but it was less robust for FSL-1 (TLR2/6 agonist) and Pam3CSK4 (TLR1/2 agonist). The greatest in vitro migration effect was observed with 6.2 μg/ml ES after 44 hrs where gap area compared to vehicle was 53.3 ± 3.7% vs. 72.6 ± 5.4% (P = 0.001). In the mouse model, the maximum healing effect was present with 1.5 μg/ml ES after 12 hrs with a wound area of 19.0 ± 2.7% vs. 60.1 ± 21.6% (P = 0.003) or 77% reduction of the wound area compared to the negative control.

CONCLUSIONS

ES significantly reduce in vitro TLR-induced production of inflammatory cytokines and promote corneal wound healing.

A human tissue-based assay identifies a novel carrion blowfly strain for maggot debridement therapy

Maggot debridement therapy (MDT) is a form of therapeutic wound treatment in which live fly larvae are used intentionally to debride necrotic tissues. MDT has been widely used to treat chronic wounds in humans or animals, such as diabetic foot ulcers. Larvae of a carrion blowfly, Lucilia sericata (green bottle fly), debride wounds by consuming necrotic tissue and removing pathogenic bacteria, promoting effective wound healing. Most medical L. sericata strains were initially collected from natural environments using animal meat as bait and reared on artificial protein-rich media or ground meat. It remains to be examined which strain would be more appropriate for MDT, whereas any method for evaluating the fly’s therapeutic potential in humans has not been available. A feeding assay was developed using minced human tissues obtained from surgical waste. To establish L. sericata strains highly eligible for MDT, carrion fly larvae were collected from 45 corpses subjected to forensic autopsy (such as decomposed bodies). Four corpse-derived L. sericata strains were obtained and evaluated using the feeding assay. One strain showed that its feeding activity was 1.4 times higher than the control strain used in conventional MDT. The body length of the adult fly of the corpse-derived strain was longer than the control, which was consistent with the observation that its cell size was enlarged. The human tissue-based assay developed in this study accurately evaluated the ability of fly larvae to debride necrotic wounds. The L. sericata strain newly established from human corpses harboring high feeding activity may offer a clinically significant improvement in MDT.

Limb Salvage with Multiple Modalities: A Case Report of a Diabetic Heel Ulcer Associated with Peripheral Arterial Disease

ABSTRACT

A large diabetic heel ulcer with peripheral arterial disease is an independent predictor of limb loss; below-knee amputation is not uncommon in such cases. One treatment is multimodal therapy, which includes partial calcanectomy. Because there is a limit to the ulcer surface area that can be sutured after partial calcanectomy, the remaining raw surface is treated with another method. In this case report, the authors describe a patient with peripheral arterial disease who had a 7 × 9-cm diabetic heel ulcer. The patient was treated with partial calcanectomy after catheter-based endovascular therapy revascularization and then maggot therapy after residual-wound dimensions were reduced by negative-pressure wound therapy.

Antimicrobial Activity of Lipid Extracts of Echinoderms in the Nhatrang Bay (South China Sea)

The obtained results on the study of the antimicrobial activity of lipid extracts of tissues of starfishes Linckia laevigata and Culcita novaeguineae and sea urchin Diadema setosum collected in the Nhatrang Bay (South China Sea) against nosocomial strains of Klebsiella pneumoniae, Enterococcus faecium, Escherichia coli, Pseudomonas aeruginosa, Candida sp., Streptococcus pyogenes, and Staphylococcus aureus are presented. The effect of the investigated extracts on Gram-positive, Gram-negative microorganisms, as well as yeast of the genus Candida, was determined. It was found that lipid extracts of echinoderms of the Nhatrang Bay exhibit the highest antimicrobial activity against the Gram-positive microorganisms, namely Streptococcus pyogenes.

The effect of Lucilia sericata larval excretion/secretion (ES) products on cellular responses in wound healing

Chronic wounds are still regarded as a serious public health concern, which are on the increase mainly due to the changes in life styles and aging of the human population. There are different types of chronic wounds, each of which requires slightly different treatment strategies. Nevertheless, wound bed preparation is included in treatment of all types of chronic wounds and involves tissue debridement, inflammation, and infection control, as well as moisture balance and epithelial edge advancement. Maggot therapy (MT) is a form of biological debridement which involves the application of live medical grade Lucilia sericata (Meigen, 1826) (Diptera: Calliphoridae) larvae. Whereas it was initially thought to act mainly through debridement, today MT is known to influence all four overlapping physiological phases of wound repair: homeostasis, inflammation, proliferation, and remodelling/maturing. During MT, medical-grade larvae are applied either freely or enclosed in tea-bag like devices (biobag) inside the wounds, which suggests that larva excretion/secretion (ES) products can facilitate the healing processes directly without the need of direct contact with the larvae. This review summarizes the relevant literature on ES-mediated effects on the cellular responses involved in wound healing.

A molecular approach to maggot debridement therapy with Lucilia sericata and its excretions/secretions in wound healing

Chronic wounds caused by underlying physiological causes such as diabetic wounds, pressure ulcers, venous leg ulcers and infected wounds affect a significant portion of the population. In order to treat chronic wounds, a strong debridement, removal of necrotic tissue, elimination of infection and stimulation of granulation tissue are required. Maggot debridement therapy (MDT), which is an alternative treatment method based on history, has been used quite widely. MDT is an efficient, simple, cost-effective and reliable biosurgery method using mostly larvae of Lucilia sericata fly species. Larvae can both physically remove necrotic tissue from the wound site and stimulate wound healing by activating molecular processes in the wound area through the enzymes they secrete. The larvae can stimulate wound healing by activating molecular processes in the wound area through enzymes in their excretions/secretions (ES). Studies have shown that ES has antibacterial, antifungal, anti-inflammatory, angiogenic, proliferative, hemostatic and tissue-regenerating effects both in vivo and in vitro. It is suggested that these effects stimulate wound healing and accelerate wound healing by initiating a direct signal cascade with cells in the wound area. However, the enzymes and peptides in ES are mostly still undefined. Examining the molecular content of ES and the biological effects of these ingredients is quite important to illuminate the molecular mechanism underlying MDT. More importantly, ES has the potential to have positive effects on wound healing and to be used more as a therapeutic agent in the future, so it can be applied as an alternative to MDT in wound healing.

Maggot debridement therapy in critical limb ischaemia: a case study

OBJECTIVE

In critical limb ischaemia (CLI), first-line therapy is revascularisation, but alternative treatment options are needed in certain cases. Maggot debridement therapy (MDT) is historically considered to be contraindicated in ischaemic ulcers. Wound care in patients with CLI is becoming increasingly diverse with the development of novel revascularisation strategies; therefore, CLI now needs to be reconsidered as an indication for MDT.

METHOD

We retrospectively reviewed five legs with CLI (five male, one female) treated with MDT between January 2013 and December 2017. Changes in skin perfusion pressure (SPP) around the ulcer before and after MDT were evaluated. One or two cycles of MDT were performed (eight in total). We also evaluated the proportion of necrotic tissue in the ulcer and the presence of exposed necrotic bone. The proportion of necrotic tissue in the ulcer was classified as NT 1+ (<25%), NT 2+ (25-50%), NT 3+ (50-75%) or NT 4+ (>75%).

RESULTS

When the proportion of necrotic tissue was >50%, with no exposed necrotic bone in the wound, an increase in SPP was observed after five (62.5%) of eight cycles of MDT. And with a proportion of necrotic tissue of <25% and/or exposed necrotic bone in the wound, a decrease in SPP was observed after three (37.5%) of eight cycles. Wound healing was accelerated in the presence of increased SPP.

CONCLUSION

Effective MDT with increased SPP requires an ulcerative state of necrotic tissue grade > NT 3+, with no exposed necrotic bone.

The role of Helianthus tuberosus powder in healing of full-thickness wounds in mice

Background and Aim

Recently, many medicinal plants have received considerable attention in the medical field because of their role in the wound healing potential. This study aimed to determine the effectiveness of H. tuberosus powder on the healing pathway of full-thickness cutaneous wounds in a mouse model.

Materials and Methods

H. tuberosus powder was prepared by a freeze-drying process using a lyophilizer and its active ingredients were evaluated by high-performance liquid chromatography (HPLC), while its antibacterial properties were evaluated by agar well diffusion assay. The percentage wound contraction was also assessed. Thirty mice were used, which were divided equally into two groups, a control group and a treated group. A full-thickness wound, 1 cm×1 cm in size, was established on the dorsal aspect of the thoracolumbar region, into which H. tuberosus powder was topically applied in the treated group. In contrast, the control group was left without any treatment. The animals were euthanized on days 7, 14, and 21 after wounding for histopathological study.

Results

The agar well diffusion method indicated the antibacterial activity of H. tuberosus, while the HPLC results indicated that the active ingredients of H. tuberosus powder mainly consisted of three major kinds of fatty acid. In addition, the macroscopic results of wound contraction rate and the histopathological outcomes of the healing process were significantly (p≤0.05) enhanced in the treated group compared with those in the control group.

Conclusion

H. tuberosus powder acts as an antibacterial agent with the ability to enhance the wound healing process.

Evaluation of Larval Therapy Compared to Antibiotic Therapy in the Treatment of Skin Wounds in Rabbits

Larval therapy (LT) is a therapeutic modality that uses larvae of necrophagous flies for the treatment of wounds. The use of this therapy presents several benefits, due to the action of the larvae that remove necrotic tissue selectively, exercising antimicrobial action, and promoting healing. There are situations in which LT proves to be the only or the best alternative for the patient, such as wounds infected by multidrug-resistant microorganisms or when treatment difficulties may lead to an indication for amputation. The purpose of this study was to compare the efficiency of LT, using larvae of Chrysomya megacephala, with that of antibiotic therapy in the treatment of cutaneous wounds infected with Pseudomonas aeruginosa. Twenty-four rabbits were used to perform the experiment, distributed in four groups: group 1, induced wound without bacterial infection; group 2, induced wound with bacterial infection; group 3, induced wound with bacterial infection and antibiotic therapy; group 4, induced wound with bacterial infection and LT. The macroscopic, microscopic, and statistical analyses indicated that LT was as effective as antibiotic therapy in wound healing.

Antibacterial fatty acids: An update of possible mechanisms of action and implications in the development of the next-generation of antibacterial agents

The antibacterial activity of fatty acids (FA) is well known in the literature and represents a promising option for developing the next-generation of antibacterial agents to treat a broad spectrum of bacterial infections. FA are highly involved in living organisms' defense system against numerous pathogens, including multidrug-resistant bacteria. When combined with other antibacterial agents, the remarkable ability of FA to enhance their bactericidal properties is a critical feature that is not commonly observed in other naturally-occurring compounds. More reviews focusing on FA antibacterial activity, traditional and non-traditional mechanisms and biomedical applications are needed. This review is intended to update the reader on the antibacterial properties of recent FA and how their chemical structures influence their antibacterial activity. This review also aims to better understand both traditional and non-traditional mechanisms involved in these recently explored FA antibacterial activities.

Bioactive Fatty Acids in the Resolution of Chronic Inflammation in Skin Wounds

Significance: Optimal skin wound healing is crucial for maintaining tissue homeostasis, particularly in response to an injury. The skin immune system is under regulation of mediators such as bioactive lipids and cytokines that can initiate an immune response with controlled inflammation, followed by efficient resolution. However, nutritional deficiency impacts wound healing by hindering fibroblast proliferation, collagen synthesis, and epithelialization, among other crucial functions. In this way, the correct nutritional support of bioactive lipids and of other essential nutrients plays an important role in the outcome of the wound healing process. Recent Advances and Critical Issues: Several studies have revealed the potential role of lipids as a treatment for the healing of skin wounds. Unsaturated fatty acids such as linoleic acid, α-linolenic acid, oleic acid, and most of their bioactive products have shown an effective role as a topical treatment of chronic skin wounds. Their effect, when the treatment starts at day 0, has been observed mainly in the inflammatory phase of the wound healing process. Moreover, some of them were associated with different dressings and were tested for clinical purposes, including pluronic gel, nanocapsules, collagen films and matrices, and polymeric bandages. Therefore, future research is still needed to evaluate these dressing technologies in association with different bioactive fatty acids in a wound healing context. Future Directions: This review summarizes the main results of the available clinical trials and basic research studies and provides evidence-based conclusions. Together, current data encourage the use of bioactive fatty acids for an optimal wound healing resolution.

Maggot excretions/secretions promote diabetic wound angiogenesis via miR18a/19a - TSP-1 axis

AIMS

The impaired angiogenesis is one of the main factors affecting the healing of diabetic foot ulcer (DFU) wounds. Maggot debridement therapy (MDT) promotes granulation tissue growth and angiogenesis during DFU wound healing. Non-coding microRNAs can also promote local angiogenesis in DFU wounds by regulating wound repairing related gene expression. The purpose of this study was to investigate the mechanism of microRNAs in MDT promoting DFU wound angiogenesis.

METHODS

In this study, we applied MDT to treat DFU wound tissue and detect the expression of the miR-17-92 cluster. In vitro experiments, human umbilical vein endothelial cells (HUVECs) were treated with maggot excretions/secretions (ES), the miR-17-92 cluster and the predicted target gene expression were measured. Tube formation assay and cell scratch assay were performed when inhibition of miR-18a/19a or overexpression of thrombospondin-1 (TSP-1) were used in this study.

RESULTS

miR-18a/19a transcription significantly up-regulated and TSP-1 expression down-regulated in patients wound tissue and in HUVECs. Inhibition of miR-18a/19a or overexpression of TSP-1 partially blocked the migration and tube formation ability stimulated by ES.

CONCLUSION

Targeted activation of miR-18a/19a transcription levels and subsequent regulation of TSP-1 expression may be a novel therapeutic strategy for DFU.

Polysaccharide extracted from WuGuChong reduces high-fat diet-induced obesity in mice by regulating the composition of intestinal microbiota

Background

Obesity is a severe public health threat worldwide. Emerging evidence suggests that gut microbiota dysbiosis is closely associated with obesity and its related metabolic complications. The aim of the present study is to investigate the effects of polysaccharide extracted from WuGuChong (PEW) on high-fat diet (HFD)-induced obesity, and the potential mechanisms involving modulation of the gut microbiota composition.

Methods

Mice were fed a normal chow diet and a high-fat diet with or without PEW (300 mg/kg/day) by oral gavage for 8 weeks. Body weight, obesity-related metabolic disorders, and gut microbiota were examined at the end of the experiment.

Results

PEW supplementation reduces body weight, adipose hypertrophy, liver steatosis, insulin resistance and systemic inflammation in HFD-fed mice, as well as maintains intestinal epithelium integrity. High-throughput 16S rRNA analysis demonstrates that PEW supplementation alters the composition of gut microbiota. The Firmicutes to Bacteroidetes ratio and the relative abundance of Proteobacteria are increased in HFD-fed mice, which are reversed by PEW supplementation to approximately the control levels.

Conclusions

Our results suggest that PEW may be used as a bioactive ingredient to prevent obesity and its related metabolic disorders by modulating the composition of gut microbiota.

Fatty acid extracts facilitate cutaneous wound healing through activating AKT, ERK, and TGF-β/Smad3 signaling and promoting angiogenesis

Fatty acids (FAs) are potential therapeutic agents for cutaneous wound healing; however, the mechanisms underlying this effect have not been clearly defined. In this study, we extracted and characterized FAs from dried Lucilia sericata larvae and investigated the molecular basis by which FAs promote cutaneous wound healing. We first confirmed that FA sodium salts (FASSs) stimulated proliferation, migration, and tube formation of cultured human umbilical vein endothelial cells (HUVECs) in a dose-dependent manner. We then showed that FASSs promoted endothelial-to-mesenchymal transition (EndMT), which plays an important role in stabilizing the neovasculature during angiogenesis. Mechanistically, FASSs up-regulated the expression of angiogenesis-related growth factors, platelet-derived growth factor (PDGF), transforming growth factor-β1 (TGF-β1), and vascular endothelial growth factor A (VEGFA), and activated angiogenesis-related signaling pathways, AKT, ERK, and TGF-β/Smad3. In a rat acute cutaneous-wound model, FAs promoted wound healing. Following treatment, we further found that expression of anti-apoptosis-related factors (c-Myc and Bcl-2) was up-regulated and expression of apoptosis-related factors (p53 and Bad) was down-regulated. Our findings suggest that FAs can promote cutaneous wound healing by inducing angiogenesis, partly by activating AKT, ERK, and TGF-β/Smad3 signaling.

Regeneration and Repair of Skin Wounds: Various Strategies for Treatment

Skin as a mechanical barrier between the inner and outer environment of our body protects us against infection and electrolyte loss. This organ consists of 3 layers: the epidermis, dermis, and hypodermis. Any disruption in the integrity of skin leads to the formation of wounds, which are divided into 2 main categories: acute wounds and chronic wounds. Generally, acute wounds heal relatively faster. In contrast to acute wounds, closure of chronic wounds is delayed by 3 months after the initial insult. Treatment of chronic wounds has been one of the most challenging issues in the field of regenerative medicine, promoting scientists to develop various therapeutic strategies for a fast, qualified, and most cost-effective treatment modality. Here, we reviewed more recent approaches, including the development of stem cell therapy, tissue-engineered skin substitutes, and skin equivalents, for the healing of complex wounds.

Antibacterial and anti-biofilm effects of fatty acids extract of dried Lucilia sericata larvae against Staphylococcus aureus and Streptococcus pneumoniae in vitro

Development of new effective antimicrobial drugs is still a big challenge to date due to microbial infection remains an inevitable problem against human health. In this study, fatty acids extract of Lucilia sericata larvae (LFAs) was obtained and evaluated by gas chromatograph-mass spectrometry (GC-MS), and its antibacterial activity against Staphylococcus aureus (S. aureus) and Streptococcus pneumoniae (S. pneumoniae) was investigated. We found that LFAs exhibited effective antibacterial activity against S. aureus and S. pneumoniae with minimal inhibitory concentrations (MICs) of 125 μg/mL and 100 μg/mL, respectively. The bacterial wall and membrane were the main targets, which was confirmed by fluorescence microscopy, scanning electron microscopy and transmission electron microscopy. Furthermore, a notable anti-biofilm activity against S. aureus and S. pneumoniae was also observed, which was able to both prevent biofilm formation and eradicate mature biofilms of these bacteria. As a promising antibacterial agent, LFAs showed good application prospects in clinical practice.

Evaluation of Wound Dressing Made From Spider Silk Protein Using in a Rabbit Model

The aim of the present article was to study the healing of wounds using spider silk. Eight New Zealand female rabbits were selected as animal model. First, 3 identical wounds with length of 15 mm and a depth of 4 mm on the back of each rabbit were created. The first group, as standard control, did not receive any special treatment, they were treated only with saline and Vaseline locally. The second group, as positive control, received a thin film of phenytoin 1% ointment locally. The third group, as treated group, received a thin film of spider silk protein. At the end of the study, a biopsy of skin was done. After tissue preparation, all sections were evaluated. Some morphometrical parameters such as counting cells, fibroblasts, blood vessels, determination of the area of the wound closure, necrotic tissue, speed of wound healing, and epidermal thickness were done, and for data statistical analysis, SPSS software and Excel software were used. The results of this study showed that spider silk dressing may benefit as a possible effect of nanoparticles in the test preparation in wound healing.

Pharmacological Properties of the Medical Maggot: A Novel Therapy Overview

In the last decade, maggot has been hailed as the miraculous “medicinal maggot” for its diverse properties, including antimicrobial, antibiofilm, anti-inflammatory, and wound healing activities. The fact that maggots show so many beneficial properties has increased the interest in these tiny larvae dramatically. Whilst there is relatively abundant clinical evidence to demonstrate the success of maggots as debridement agents, not so much emphasis has been placed on the basic science evidence, which was a combination of physical and biochemical actions. This review differs from those earlier works in that it is undertaken to provide an update of the latest scientific basis published on maggot, particularly active ingredients within maggot excretions/secretions (ES). Further investigations should focus on the isolation, identification, recombination, transgenosis, and mass production of the beneficial molecules within maggots.

The transcriptional responses of cultured wound cells to the excretions and secretions of medicinal Lucilia sericata larvae

Maggots, through their excretions and secretions (ES), promote wound healing by removing necrotic tissue, counter bacterial infection, and activate wound associated cells. We investigated the effects of a physiological dose of maggot ES on four wound-associated cell types in vitro with Affymetrix gene expression arrays; keratinocytes, endothelial cells, fibroblasts, and monocytes. Keratinocytes showed the fewest (n = 5; p < 0.05, fold-change ±2) and smallest fold-changes (up to 2.32×) in gene expression and conversely THP1 monocytes had the most (n = 233) and greatest magnitude (up to 44.3×). There were no genes that were altered in all four cell-lines. Gene pathway analysis identified an enrichment of immune response pathways in three of the treated cell-lines. Analyses by quantitative RT-PCR found many genes dynamically expressed in ES dose dependent manner during the three day treatments. Phenotype analyses, however, found no effects of ES on cell viability, proliferation, migration and angiogenesis. ES was 100× less potent at triggering IL-8 secretion than fibroblasts treated with purified bacterial lipopolysaccharide (LPS; in equivalent amounts to that found in ES; ∼40 EU/ml). Furthermore, co-treatment with LPS and ES decreased the LPS-alone triggered IL-8 secretion by 13%. Although ES had no direct effect on wound cell phenotypes it did partially reduce the immune response to bacterial LPS exposure. These observations were consistent with the profile of transcriptional responses that were dominated by modulation of immune response genes. Maggot therapy may therefore improve wound healing through the secondary effects of these gene changes in the wound cells.

Fatty acid supplements improve hair coat condition in rhesus macaques

As captive rhesus macaques often exhibit hair loss, alopecia was quantified and behavior was recorded before, during, and after fatty acid supplementation in six macaques. Fatty acid treatment was associated with a decrease in alopecia and in self-grooming behavior. Therefore, fatty acids may be a viable treatment for alopecia in some captive primates.

Next Generation Sequencing Identifies Five Major Classes of Potentially Therapeutic Enzymes Secreted by Lucilia sericata Medical Maggots

Lucilia sericata larvae are used as an alternative treatment for recalcitrant and chronic wounds. Their excretions/secretions contain molecules that facilitate tissue debridement, disinfect, or accelerate wound healing and have therefore been recognized as a potential source of novel therapeutic compounds. Among the substances present in excretions/secretions various peptidase activities promoting the wound healing processes have been detected but the peptidases responsible for these activities remain mostly unidentified. To explore these enzymes we applied next generation sequencing to analyze the transcriptomes of different maggot tissues (salivary glands, gut, and crop) associated with the production of excretions/secretions and/or with digestion as well as the rest of the larval body. As a result we obtained more than 123.8 million paired-end reads, which were assembled de novo using Trinity and Oases assemblers, yielding 41,421 contigs with an N50 contig length of 2.22 kb and a total length of 67.79 Mb. BLASTp analysis against the MEROPS database identified 1729 contigs in 577 clusters encoding five peptidase classes (serine, cysteine, aspartic, threonine, and metallopeptidases), which were assigned to 26 clans, 48 families, and 185 peptidase species. The individual enzymes were differentially expressed among maggot tissues and included peptidase activities related to the therapeutic effects of maggot excretions/secretions.

Poly (3-hydroxyalkanoates)-co-(6-hydroxyhexanoate) hydrogel promotes angiogenesis and collagen deposition during cutaneous wound healing in rats

Wound management and healing in several physiological or pathological conditions, particularly when comorbidities are involved, usually proves to be difficult. This presents complications leading to socio-economic and public health burdens. The accelerative wound healing potential of biocompatible poly(3-hydroxyalkanoates)-co-(6-hydroxyhexanoate) (PHA-PCL) composite hydrogel is reported herein. The biosynthesized PHA-PCL macromer was cross-linked with PEGMA to give a hydrogel. Twenty-four rats weighing 200-250 g each were randomly assigned to four groups of six rats. Rats in group I (negative control) were dressed with sterilized gum acacia paste in 10% normal saline while PEGMA-alone hydrogel (PH) was used to dress group II (secondary control) rats. Group III rats were dressed with PHAs-PCL cross-linked PEGMA hydrogel (PPH). For the positive control (group IV), the rats were dressed with Intrasite(®) gel. Biochemical, histomorphometric and immunohistomorphometric analyses revealed a significant difference in area closure and re-epithelialization on days 7 and 14 in PPH or Intrasite(®) gel groups compared to gum acacia or PEGMA-alone groups. Furthermore, wounds dressed with PPH or Intrasite(®) gel showed evident collagen deposition, enhanced fibrosis and extensively organized angiogenesis on day 14 compared to the negative control group. While improvement in wound healing of the PH dressed group could be observed, there was no significant difference between the negative control group and the PH dressed group in any of the tests. The findings suggested that topical application of PPH accelerated the rats' wound healing process by improving angiogenesis attributed to the increased microvessel density (MVD) and expressions of VEGF-A in tissue samples. Thus, PPH has been demonstrated to be effective in the treatment of cutaneous wounds in rats, and could be a potential novel agent in the management and acceleration of wound healing in humans and animals.

Evaluation of larval density Cochliomyia macellaria F. (Diptera: Calliphoridae) for therapeutic use in the recovery of tegumentar injuries

Larval therapy (LT) is the application of carrion flies (Diptera) sterile larvae on chronic or infected wounds to promote or accelerate the healing process. High cost and the development of resistance by certain groups of pathogenic bacteria to these drugs encouraged the resurgence of LT, currently used in approximately 20 countries and more recently in Brazil. This study evaluated the behavior and larval density of Cochliomyia macellaria F. (Calliphoridae), one of the most appropriate species for debridement of injuries with necrotic tissue. Tegumentar lesions were induced in Wistar rats by subcutaneously application of 0.2 ml of a 1:4 hydrochloric acid and sterile distilled water in the dorsal region. Five experimental groups were set up: (LT 5) treatment with 5 larvae/cm(2); (LT 15) 15 larvae/cm(2); (LT 25) 25 larvae/cm(2); (DEB) mechanical debridement, and (NUL) animals that did not receive any treatment. In the LT groups, larvae used were sterilized with sodium hypochlorite (NaClO) and maintained for 12 h in the lesions. The healing process was assessed qualitatively (macroscopically and microscopically) and quantitatively (time interval to complete healing). It was observed that the immature fed only on necrotic tissue, thus C. macellaria is an excellent candidate for use in LT. There was no significant difference in healing time between experimental groups. However, it was observed that in LT 25, there was greater vascularization in tissues when compared to the other treatments. The mechanisms involved in this process are unknown, but it is evident that the larvae have an important role in modulating the host immune response. It is essential that future applications of larval therapy consider using a higher density of larvae (minimum of 25 larvae/cm(2)) than is currently recommended.

Maggot excretion products from the blowfly Lucilia sericata contain contact phase/intrinsic pathway-like proteases with procoagulant functions

For centuries, maggots have been used for the treatment of wounds by a variety of ancient cultures, as part of their traditional medicine. With increasing appearance of antimicrobial resistance and in association with diabetic ulcers, maggot therapy was revisited in the 1980s. Three mechanisms by which sterile maggots of the green bottle fly Lucilia sericata may improve healing of chronic wounds have been proposed: Biosurgical debridement, disinfecting properties, and stimulation of the wound healing process. However, the influence of maggot excretion products (MEP) on blood coagulation as part of the wound healing process has not been studied in detail. Here, we demonstrate that specific MEP-derived serine proteases from Lucilia sericata induce clotting of human plasma and whole blood, particularly by activating contact phase proteins factor XII and kininogen as well as factor IX, thereby providing kallikrein-bypassing and factor XIa-like activities, both in plasma and in isolated systems. In plasma samples deficient in contact phase proteins, MEP restored full clotting activity, whereas in plasma deficient in either factor VII, IX, X or II no effect was seen. The observed procoagulant/intrinsic pathway-like activity was mediated by (chymo-) trypsin-like proteases in total MEP, which were significantly blocked by C1-esterase inhibitor or other contact phase-specific protease inhibitors. No significant influence of MEP on platelet activation or fibrinolysis was noted. Together, MEP provides contact phase bypassing procoagulant activity and thereby induces blood clotting in the context of wound healing. Further characterisation of the active serine protease(s) may offer new perspectives for biosurgical treatment of chronic wounds.

Characterisation of the small RNAs in the biomedically important green-bottle blowfly Lucilia sericata

BACKGROUND

The green bottle fly maggot, Lucilia sericata, is a species with importance in medicine, agriculture and forensics. Improved understanding of this species' biology is of great potential benefit to many research communities. MicroRNAs (miRNA) are a short non-protein coding regulatory RNA, which directly regulate a host of protein coding genes at the translational level. They have been shown to have developmental and tissue specific distributions where they impact directly on gene regulation. In order to improve understanding of the biology of L. sericata maggots we have performed small RNA-sequencing of their secretions and tissue at different developmental stages.

RESULTS

We have successfully isolated RNA from the secretions of L. sericata maggots. Illumina small RNA-sequencing of these secretions and the three tissues (crop, salivary gland, gut) revealed that the most common small RNA fragments were derived from ribosomal RNA and transfer RNAs of both insect and bacterial origins. These RNA fragments were highly specific, with the most common tRNAs, such as GlyGCC, predominantly represented by reads derived from the 5' end of the mature maggot tRNA. Each library also had a unique profile of miRNAs with a high abundance of miR-10-5p in the maggot secretions and gut and miR-8 in the food storage organ the crop and salivary glands. The pattern of small RNAs in the bioactive maggot secretions suggests they originate from a combination of saliva, foregut and hindgut tissues. Droplet digital RT-PCR validation of the RNA-sequencing data shows that not only are there differences in the tissue profiles for miRNAs and small RNA fragments but that these are also modulated through developmental stages of the insect.

CONCLUSIONS

We have identified the small-RNAome of the medicinal maggots L. sericata and shown that there are distinct subsets of miRNAs expressed in specific tissues that also alter during the development of the insect. Furthermore there are very specific RNA fragments derived from other non-coding RNAs present in tissues and in the secretions. This new knowledge has applicability in diverse research fields including wound healing, agriculture and forensics.

Evaluating the effect of Sarconesiopsis magellanica (Diptera: Calliphoridae) larvae-derived haemolymph and fat body extracts on chronic wounds in diabetic rabbits

We evaluated extracts taken from S. magellanica third instar larvae fat body and haemolymph using a diabetic rabbit model and compared this to the effect obtained with the same substances taken from Lucilia sericata larvae. Alloxan (a toxic glucose analogue) was used to induce experimental diabetes in twelve rabbits. Dorsal wounds were made in each animal and they were infected with Staphylococcus aureus and Pseudomonas aeruginosa. They were then treated with haemolymph and lyophilized extracts taken from the selected blowflies' larvae fat bodies. Each wound was then evaluated by using rating scales and histological analysis. More favourable scores were recorded on the PUSH and WBS scales for the wounds treated with fat body derived from the larvae of both species compared to that obtained with haemolymph; however, wounds treated with the substances taken from S. magellanica had better evolution. Histological analysis revealed that treatment led to tissue proliferation and more effective neovascularisation in less time with both species' fat body extracts compared to treatment with just haemolymph. The results suggest the effectiveness of the substances evaluated and validate them in the animal model being used here as topical agents in treating chronic wounds.

Recent advances in developing insect natural products as potential modern day medicines

Except for honey as food, and silk for clothing and pollination of plants, people give little thought to the benefits of insects in their lives. This overview briefly describes significant recent advances in developing insect natural products as potential new medicinal drugs. This is an exciting and rapidly expanding new field since insects are hugely variable and have utilised an enormous range of natural products to survive environmental perturbations for 100s of millions of years. There is thus a treasure chest of untapped resources waiting to be discovered. Insects products, such as silk and honey, have already been utilised for thousands of years, and extracts of insects have been produced for use in Folk Medicine around the world, but only with the development of modern molecular and biochemical techniques has it become feasible to manipulate and bioengineer insect natural products into modern medicines. Utilising knowledge gleaned from Insect Folk Medicines, this review describes modern research into bioengineering honey and venom from bees, silk, cantharidin, antimicrobial peptides, and maggot secretions and anticoagulants from blood-sucking insects into medicines. Problems and solutions encountered in these endeavours are described and indicate that the future is bright for new insect derived pharmaceuticals treatments and medicines.

Mechanisms of maggot-induced wound healing: what do we know, and where do we go from here?

MEDICINAL MAGGOTS ARE BELIEVED TO HAVE THREE MAJOR MECHANISMS OF ACTION ON WOUNDS, BROUGHT ABOUT CHEMICALLY AND THROUGH PHYSICAL CONTACT: debridement (cleaning of debris), disinfection, and hastened wound healing. Until recently, most of the evidence for these claims was anecdotal; but the past 25 years have seen an increase in the use and study of maggot therapy. Controlled clinical studies are now available, along with laboratory investigations that examine the interaction of maggot and host on a cellular and molecular level. This review was undertaken to extract the salient data, make sense, where possible, of seemingly conflicting evidence, and reexamine our paradigm for maggot-induced wound healing. Clinical and laboratory data strongly support claims of effective and efficient debridement. Clinical evidence for hastened wound healing is meager, but laboratory studies and some small, replicated clinical studies strongly suggest that maggots do promote tissue growth and wound healing, though it is likely only during and shortly after the period when they are present on the wound. The best way to evaluate-and indeed realize-maggot-induced wound healing may be to use medicinal maggots as a "maintenance debridement" modality, applying them beyond the point of gross debridement.

Sterilization of Chrysomya putoria (Insecta: Diptera: Calliphoridae) eggs for use in biotherapy

Large-scale, quality-controlled laboratory production of fly larvae is needed for biotherapy. The objective of this study was to assess the action of glutaraldehyde on the sterilization of Chrysomya putoria eggs by applying pharmaceutical sterility tests. Egg masses with 0.600 g were divided into three parts of 0.200 g, the eggs were separated using sterile distilled water, and the suspensions obtained were mixed with activated 2% glutaraldehyde solution. After 15-min contact, the suspensions were filtered through Whatman filter paper, and the glutaraldehyde residue obtained in the filtrate was neutralized by rinsing with Tryptone Soy Broth. The treated eggs were placed aseptically on Petri dishes containing gauze moistened with sterile saline solution. About 10% of the sterilized mass was transferred to test tubes containing Tryptone Soy Broth and Fluid Thioglycollate Broth. The tubes were incubated, respectively, at 22.5 and 35.0°C for 14 d to verify egg mass sterility. The plates containing the rest of the eggs (90%) were sealed with plastic film and kept in a climatized chamber at 30°C/d, 28°C per night, 60 ± 10% relative humidity, and under a 12-h light period to assess insect viability and survival. Each experiment was carried out in triplicate using a biological class II safety cabinet. No change in color or turgidity was observed with the agent tested, proving the sterility of the product and that there was no trace of contamination. Forty larvae (in three replications) in the periods of 12, 24, and 48 h after sterilization, when transferred to diet, produced larvae, pupae, and total viability similar to the control (larvae without sterilization). However, for the 72-h treatment, larvae and total viability were significantly lower than for the other treatments. There was no significant difference for the pupal stage. The product tested was shown to be efficacious for use as a sterilizer of C. putoria eggs for all the parameters assessed.

Effect of semisolid formulation of persea americana mill (avocado) oil on wound healing in rats

The aim of this study was to evaluate the wound-healing activity of a semisolid formulation of avocado oil, SSFAO 50%, or avocado oil in natura, on incisional and excisional cutaneous wound models in Wistar rats. An additional objective was to quantify the fatty acids present in avocado oil. On the 14th day, a significant increase was observed in percentage wound contraction and reepithelialization in the groups treated with 50% SSFAO or avocado oil compared to the petroleum jelly control. Anti-inflammatory activity, increase in density of collagen, and tensile strength were observed inSSFAO 50% or avocado oil groups, when compared to control groups. The analysis of the components of avocado oil by gas chromatography detected the majority presence of oleic fatty acid (47.20%), followed by palmitic (23.66%), linoleic (13.46%) docosadienoic (8.88%), palmitoleic (3.58%), linolenic (1.60%), eicosenoic (1.29%), and myristic acids (0.33%). Our results show that avocado oil is a rich source of oleic acid and contains essential fatty acids. When used in natura or in pharmaceutical formulations for topical use, avocado oil can promote increased collagen synthesis and decreased numbers of inflammatory cells during the wound-healing process and may thus be considered a new option for treating skin wounds.

Cuticular and internal n-alkane composition of Lucilia sericata larvae, pupae, male and female imagines: application of HPLC-LLSD and GC/MS-SIM

The composition of cuticular and internal n-alkanes in Lucilia sericata larvae, pupae, and male and female imagines were studied. The cuticular and internal lipid extracts were separated by HPLC-LLSD, after which the hydrocarbon fraction was identified by GC/MS in selected ion monitoring (SIM) and total ion current (TIC) modes. The cuticular lipids of the larvae contained seven n-alkanes from C23 to C31. The major n-alkane in L. sericata larvae was C29 (42.1%). The total cuticular n-alkane content in the cuticular lipids was 31.46 μg g-1 of the insect body. The internal lipids of L. sericata larvae contained five n-alkanes ranged from C25 to C31. The most abundant compound was C27 (61.71 μg g-1 of the insect body). Eighteen n-alkanes from C14 to C31 were identified in the cuticular lipids of the pupae. The most abundant n-alkanes ranged from C25 to C31; those with odd-numbered carbon chains were particularly abundant, the major one being C29:0 (59.5%). Traces of eight cuticular n-alkanes were present. The internal lipids of L. sericata pupae contained five n-alkanes, ranging from C25 to C31. The cuticular lipids of female imagines contained 17 n-alkanes from C12 to C30. Among the cuticular n-alkanes of females, C27 (47.5%) was the most abundant compound. Four n-alkanes, with only odd-numbered carbon chains, were identified in the internal lipids of females. The lipids from both sexes of L. sericata had similar n-alkane profiles. The cuticular lipids of adult males contained 16 n-alkanes ranging from C13 to C31. C27 (47.9%) was the most abundant cuticular n-alkanes in males. The same n-alkanes only with odd-numbered carbon chains and in smaller quantities of C27 (0.1%) were also identified in the internal lipids of males. The highest amounts of total cuticular n-alkanes were detected in males and females of L. sericata (330.4 and 158.93 μg g-1 of the insect body, respectively). The quantities of total cuticular alcohols in larvae and pupae were smaller (31.46 μg g-1 and 42.08 μg g-1, respectively). The internal n-alkane contents of larvae, pupae, and male and female imagines were significantly higher than the cuticular n-alkane contents (153.53, 99.60, 360.06 and 838.76 μg g-1 of the insect body, respectively).

The composition of the cuticular and internal free fatty acids and alcohols from Lucilia sericata males and females

GC, GC-MS, and HPLC-LLSD analyses were used to identify and quantify cuticular and internal lipids in males and females of the blow-fly (Lucilia sericata). Sixteen free fatty acids, seven alcohols and cholesterol were identified and quantitatively determined in the cuticular lipids of L. sericata. Cuticular fatty acids ranged from C(6) to C(20) and included unsaturated entities such as 16:1n-9, 18:1n-9, 20:4n-3 and 20:5n-3. Cuticular alcohols (only saturated and even-numbered) ranged from C(12) to C(20) in males and C(10) to C(22) in females. Only one sterol was found in the cuticular lipids of both males and females. 23 free fatty acids, five alcohols and cholesterol were identified in the internal lipids. Internal fatty acids were present in large amounts-7.4 mg/g (female) and 10.1 mg/g (male). Only traces of internal alcohols (from C(14) to C(26) in males, from C(14) to C(22) in females) were found in L. sericata. Large amounts of internal cholesterol were identified in L. sericata males and females (0.49 and 0.97 mg/g of the insect body, respectively).

Insect natural products and processes: new treatments for human disease

In this overview, some of the more significant recent developments in bioengineering natural products from insects with use or potential use in modern medicine are described, as well as in utilisation of insects as models for studying essential mammalian processes such as immune responses to pathogens. To date, insects have been relatively neglected as sources of modern drugs although they have provided valuable natural products, including honey and silk, for at least 4-7000 years, and have featured in folklore medicine for thousands of years. Particular examples of Insect Folk Medicines will briefly be described which have subsequently led through the application of molecular and bioengineering techniques to the development of bioactive compounds with great potential as pharmaceuticals in modern medicine. Insect products reviewed have been derived from honey, venom, silk, cantharidin, whole insect extracts, maggots, and blood-sucking arthropods. Drug activities detected include powerful antimicrobials against antibiotic-resistant bacteria and HIV, as well as anti-cancer, anti-angiogenesis and anti-coagulant factors and wound healing agents. Finally, the many problems in developing these insect products as human therapeutic drugs are considered and the possible solutions emerging to these problems are described.