Cytotoxic and Pro-Apoptotic Effects of a Sub-Toxic Concentration of Fluvastatin on OVCAR3 Ovarian Cancer Cells After its Optimized Formulation to Melittin Nano-Conjugates

Unlocking nature's arsenal: Nanotechnology for targeted delivery of venom toxins in cancer therapy

AIM

The aim of the present review is to shed light on the nanotechnological approaches adopted to overcome the shortcomings associated with the delivery of venom peptides which possess inherent anti-cancer properties.

BACKGROUND

Venom peptides although have been reported to demonstrate anti-cancer effects, they suffer from several disadvantages such as in vivo instability, off-target adverse effects, limited drug loading and low bioavailability. This review presents a comprehensive compilation of different classes of nanocarriers while underscoring their advantages, disadvantages and potential to carry such peptide molecules for in vivo delivery. It also discusses various nanotechnological aspects such as methods of fabrication, analytical tools to assess these nanoparticulate formulations, modulation of nanocarrier polymer properties to enhance loading capacity, stability and improve their suitability to carry toxic peptide drugs.

CONCLUSION

Nanotechnological approaches bear great potential in delivering venom peptide-based molecules as anticancer agents by enhancing their bioavailability, stability, efficacy as well as offering a spatiotemporal delivery approach. However, the challenges associated with toxicity and biocompatibility of nanocarriers must be duly addressed.

PERSPECTIVES

The everlasting quest for new breakthroughs for safer delivery of venom peptides in human subjects is fuelled by unmet clinical needs in the current landscape of chemotherapy. In addition, exhaustive efforts are required in obtaining and purifying the venom peptides followed by designing and optimizing scale up technologies.

Immunomodulatory activities and biomedical applications of melittin and its recent advances

Melittin (MLT), a peptide containing 26 amino acids, is a key constituent of bee venom. It comprises ∼40%-60% of the venom's dry weight and is the main pricing index for bee venom, being the causative factor of pain. The unique properties of MLT extracted from bee venom have made it a very valuable active ingredient in the pharmaceutical industry as this cationic and amphipathic peptide has propitious effects on human health in diverse biological processes. It has the ability to strongly impact the membranes of cells and display hemolytic activity with anticancer characteristics. However, the clinical application of MLT has been limited by its severe hemolytic activity, which poses a challenge for therapeutic use. By employing more efficient mechanisms, such as modifying the MLT sequence, genetic engineering, and nano-delivery systems, it is anticipated that the limitations posed by MLT can be overcome, thereby enabling its wider application in therapeutic contexts. This review has outlined recent advancements in MLT's nano-delivery systems and genetically engineered cells expressing MLT and provided an overview of where the MLTMLT's platforms are and where they will go in the future with the challenges ahead. The focus is on exploring how these approaches can overcome the limitations associated with MLT's hemolytic activity and improve its selectivity and efficacy in targeting cancer cells. These advancements hold promise for the creation of innovative and enhanced therapeutic approaches based on MLT for the treatment of cancer.

Regulating Cholesterol in Tumorigenesis: A Novel Paradigm for Tumor Nanotherapeutics

During the past decade, "membrane lipid therapy", which involves the regulation of the structure and function of tumor cell plasma membranes, has emerged as a new strategy for cancer treatment. Cholesterol is an important component of the tumor plasma membrane and serves an essential role in tumor initiation and progression. This review elucidates the role of cholesterol in tumorigenesis (including tumor cell proliferation, invasion/metastasis, drug resistance, and immunosuppressive microenvironment) and elaborates on the potential therapeutic targets for tumor treatment by regulating cholesterol. More meaningfully, this review provides an overview of cholesterol-integrated membrane lipid nanotherapeutics for cancer therapy through cholesterol regulation. These strategies include cholesterol biosynthesis interference, cholesterol uptake disruption, cholesterol metabolism regulation, cholesterol depletion, and cholesterol-based combination treatments. In summary, this review demonstrates the tumor nanotherapeutics based on cholesterol regulation, which will provide a reference for the further development of "membrane lipid therapy" for tumors.

An Updated Review Summarizing the Anticancer Efficacy of Melittin from Bee Venom in Several Models of Human Cancers

Apitherapy (using bee products) has gained broad recognition in cancer therapeutics globally. Honeybee venom has a broad range of biological potential, and its utilization is rapidly emerging in apitherapy. Bee products have significant potential to strengthen the immune system and improve human health. Thus, this review is targeted toward recapitulating the chemo-preventive potential of melittin (MEL), which constitutes a substantial portion of honeybee venom. Honeybee venom (apitoxin) is produced in the venom gland of the honeybee abdomen, and adult bees utilize it as a primary colony defense mechanism. Apitoxin comprises numerous biologically active compounds, including peptides, enzymes, amines, amino acids, phospholipids, minerals, carbohydrates, and volatile components. We are mainly focused on exploring the potential of melittin (a peptide component) of bee venom that has shown promising potential in the treatment of several human cancers, including breast, stomach, lung, prostate, ovary, kidney, colon, gastric, esophageal, cervical cancers, melanoma, osteosarcoma, and hepatocellular carcinoma. This review has summarized all potential studies related to the anticancerous efficacy of melittin (apitoxin), its formulations, conjugates, and nano-formulations against several human carcinomas, which would further pave the way for future researchers in developing potent drugs for cancer management.

F. Alotaibi M, Nasrullah MZ, Alrabia MW, Asfour HZ, Abdel-Naim AB. Cordycepin- Melittin nanoconjugate intensifies wound healing efficacy in diabetic rats

The current study was designed to develop a nanoconjugate of cordycepin-melittin (COR-MEL) and assess its healing property in wounded diabetic rats. The prepared nanoconjugate has a particle size of 253.5 ± 17.4 nm with a polydispersity index (PDI) of 0.35 ± 0.04 and zeta potential of 17.2 ± 0.3 mV. To establish the wound healing property of the COR-MEL nanoconjugate, animal studies were pursued, where the animals with diabetes were exposed to excision and treated with COR hydrogel, MEL hydrogel, or COR-MEL nanoconjugate topically. The study demonstrated an accelerated wound contraction in COR-MEL nanoconjugate -treated diabetic rats, which was further validated by histological analysis. The nanoconjugate further exhibited antioxidant activities by inhibiting the accumulation of malondialdehyde (MDA) and exhaustion of superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzymatic activities. The nanoconjugate further demonstrated an enhanced anti-inflammatory activity by retarding the expression of interleukin (IL)-6 and tumor necrosis factor (TNF)-α. Additionally, the nanoconjugate exhibits a strong expression of transforming growth factor (TGF)-β1, vascular endothelial growth factor (VEGF)-A, and platelet-derived growth factor (PDGFR)-β, indicating enrichment of proliferation. Likewise, nanoconjugate increased the concentration of hydroxyproline as well as the mRNA expression of collagen, type I, alpha 1 (Col 1A1). Thus, it is concluded that the nanoconjugate possesses a potent wound-healing activity in diabetic rats via antioxidant, anti-inflammatory, and pro-angiogenetic mechanisms.

Optimized D-α-tocopherol polyethylene glycol succinate/phospholipid self-assembled mixed micelles: A promising lipid-based nanoplatform for augmenting the antifungal activity of fluconazole

Fluconazole (FLZ) is the most widely used antifungal agent for treating cutaneous candidiasis. Although oral FLZ has been proved to be effective, the incidence of side effects necessitates the development of an effective formulation that could surpass the pitfalls associated with systemic availability. Accordingly, this research aimed at developing a self-assembled mixed micelles topical delivery system to enhance the topical delivery of the drug. Self-assembled mixed micelles were developed using D-α-tocopheryl polyethylene glycol 1000 succinate and phospholipids and optimized using Box-Behnken design. The optimized formulation with minimized size was then tested in vivo for the antifungal activity against C. albicans in immunocompromised mice. Treatment with the optimized formulation led to decreased peripheral erythema as well as lesions due to fungal infection in comparison to raw FLZ loaded gel. Therefore, the developed formulation was found to be a promising vehicle for the treatment of cutaneous candidiasis.

Exploring cytotoxicity of cordycepin loaded nanovesicles against (HCT116) colon cancer cells: Optimization and cellular evaluation

Numerous researchers have investigated cordycepin (COR) as an anti-tumor compound. COR has been documented to have cytotoxic effects on several cancer cells. The current work used a Box-Behnken mathematical design to minimize COR's size. The design incorporated COR concentration, phospholipid concentration and sonication time as variables to minimize the vesicles of COR emulsomes (COR-EMLs). To evaluate degree of improvement of COR cytotoxicity against colorectal cancer (HCT116) cells, cell viability, cell cycle analysis and apoptosis have been assessed. In addition, wound scratching and mitochondrial membrane potential were evaluated. Results of Box-Behnken design achieved COR-EMLs sizes in range from 91.54 ± 2.3-343.83 ± 3.7 nm. Moreover, the optimized formula morphology's was evaluated using transmission electron microscope and showed nanospheres in range of 100 nm. COR released from COR-EMLs exceeded 80% after 12 h.The half-maximal inhibitory concentration (IC50) of the refined COR-EML formula was about four times lower than that of COR-raw. The cell cycle study revealed that administration of COR-EML considerably hindered HCT116 cellular propagation in contrast to plain emulsomes (EMLs) and COR-raw with a denser cell compilation in G2/M. Moreover, the optimized formula notably enhanced the proportion of cells in both the initial and late phases of apoptosis. The augmentation of COR cytotoxicity was confirmed by its inhibition of cancer cell wound healing by approximately 40%. The mitochondrial membrane potential was significantly lower than in cells treated with COR-raw and EMLs. Finally, loading COR into the EMLs increased COR's capacity to lower mitochondrial membrane functionality and significantly improved its cytotoxicity.

Peptide-Based Bioconjugates and Therapeutics for Targeted Anticancer Therapy

With rapidly growing knowledge in bioinformatics related to peptides and proteins, amino acid-based drug-design strategies have recently gained importance in pharmaceutics. In the past, peptide-based biomedicines were not widely used due to the associated severe physiological problems, such as low selectivity and rapid degradation in biological systems. However, various interesting peptide-based therapeutics combined with drug-delivery systems have recently emerged. Many of these candidates have been developed for anticancer therapy that requires precisely targeted effects and low toxicity. These research trends have become more diverse and complex owing to nanomedicine and antibody–drug conjugates (ADC), showing excellent therapeutic efficacy. Various newly developed peptide–drug conjugates (PDC), peptide-based nanoparticles, and prodrugs could represent a promising therapeutic strategy for patients. In this review, we provide valuable insights into rational drug design and development for future pharmaceutics.

Optimized 2-methoxyestradiol invasomes fortified with apamin: a promising approach for suppression of A549 lung cancer cells

Certain anticancer agents selectively target the nucleus of cancer cells. One such drug is 2-methoxyestradiol (2ME), which is used for treating lung cancer. To improve the therapeutic effectiveness of these agents, many new methods have been devised. 2ME was entrapped into the core of hydrophobic invasomes (INVA) covered with Phospholipon 90G and apamin (APA). The Box–Behnken statistical design was implemented to enhance the composition. Using Design-Expert software (Stat-Ease Inc., Minneapolis, MN), the INVA component quantities were optimized to obtain spherical particles with the smallest size, that is, a diameter of 167.8 nm. 2ME-INVA-APA significantly inhibited A549 cells and exhibited IC₅₀ of 1.15 ± 0.04 µg/mL, which is lower than raw 2ME (IC₅₀ 5.6 ± 0.2 µg/mL). Post 2ME-INVA-APA administration, a significant rise in cell death and necrosis was seen among the A549 cells compared to those treated with plain formula or 2ME alone. This effect was indicated by increased Bax expression and reduced Bcl-2 expression, as well as mitochondrial membrane potential loss. Moreover, the cell cycle analysis showed that 2ME-INVA-APA arrests the G2-M phase of the A549 cells. Additionally, it was observed that the micellar formulation of the drug increased the cell count in pre-G1, thereby exhibiting phenomenal apoptotic potential. Furthermore, it up-regulates caspase-9 and p53 and downregulates TNF-α and NF-κβ. Collectively, these findings showed that our optimized 2ME-INVA-APA could easily seep through the cell membrane and induce apoptosis in relatively low doses.

Beyond Lipid-Lowering: Effects of Statins on Cardiovascular and Cerebrovascular Diseases and Cancer

The 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors, also known as statins, are administered as first-line therapy for hypercholesterolemia, both as primary and secondary prevention. Besides the lipid-lowering effect, statins have been suggested to inhibit the development of cardiovascular disease through anti-inflammatory, antioxidant, vascular endothelial function-improving, plaque-stabilizing, and platelet aggregation-inhibiting effects. The preventive effect of statins on atherothrombotic stroke has been well established, but statins can influence other cerebrovascular diseases. This suggests that statins have many neuroprotective effects in addition to lowering cholesterol. Furthermore, research suggests that statins cause pro-apoptotic, growth-inhibitory, and pro-differentiation effects in various malignancies. Preclinical and clinical evidence suggests that statins inhibit tumor growth and induce apoptosis in specific cancer cell types. The pleiotropic effects of statins on cardiovascular and cerebrovascular diseases have been well established; however, the effects of statins on cancer patients have not been fully elucidated and are still controversial. This review discusses the recent evidence on the effects of statins on cardiovascular and cerebrovascular diseases and cancer. Additionally, this study describes the pharmacological action of statins, focusing on the aspect of ‘beyond lipid-lowering’.

Overcoming chemoresistance in glioblastoma by fluvastatin via prenylation-dependent inhibition of Ras signaling

The resistance of glioblastoma to chemotherapy remains a significant clinical problem. Targeting alternative pathways such as protein prenylation is known to be effective against many cancers. Fluvastatin is a potent competitive inhibitor of 3-hydroxy-3-methylglutaryl- CoA (HMG-CoA) reductase, thereby inhibits prenylation. We demonstrate that fluvastatin alone effectively inhibits proliferation and induces apoptosis in multiple human glioblastoma cell lines. The combination index analysis shows that fluvastatin acts synergistically with common chemotherapy drugs for glioblastoma: temozolomide and irinotecan. We further show that fluvastatin acts on glioblastoma through inhibiting prenylation-dependent Ras activation. The combination of fluvastatin and low dose temozolomide resulted in remarkable inhibition of glioblastoma tumor in mice throughout the whole treatment duration without causing toxicity. Such combinatorial effects provide the basis for utilizing these FDA-approved drugs as a potential clinical approach in overcoming resistance and improving glioblastoma treatment.

Ceftriaxone and Melittin Synergistically Promote Wound Healing in Diabetic Rats

High glucose levels in diabetic patients are implicated in delay wound healing that could lead to more serious clinical complications. The aim of the present work was to examine the formulation of ceftriaxone (CTX) and melittin (MEL) as nanoconjugate (nanocomplex)-loaded hydroxypropyl methylcellulose (HPMC) (1.5% w/v)-based hydrogel for healing of acute wounds in diabetic rats. The CTX–MEL nanoconjugate, formulated by ion-pairing at different molar ratio, was characterized for size and zeta potential and investigated by transmission electron microscopy. CTX–MEL nanoconjugate was prepared, and its preclinical efficacy evaluated in an in vivo model of acute wound. In particular, the potential ability of the innovative CTX–MEL formulation to modulate wound closure, oxidative status, inflammatory markers, and hydroxyproline was evaluated by ELISA, while the histopathological examination was obtained by using hematoxylin and eosin or Masson’s trichrome staining techniques. Quantitative real-time PCR (qRT-PCR) of the excised tissue to measure collagen, type I, alpha 1 (Col1A1) expression and immunohistochemical assessment of vascular endothelial growth factor A (VEGF-A) and transforming growth factor beta 1 (TGF-β1) were also carried out to shed some light on the mechanism of wound healing. Our results show that the CTX–MEL nanocomplex has enhanced ability to regenerate epithelium, also giving better keratinization, epidermal proliferation, and granulation tissue formation, compared to MEL, CTX, or positive control. The nanocomplex also significantly ameliorated the antioxidant status by decreasing malondialdehyde (MDA) and increasing superoxide dismutase (SOD) levels. The treatment of wounded skin with the CTX–MEL nanocomplex also showed a significant reduction in interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) pro-inflammatory cytokines combined with a substantial increase in hydroxyproline, VEFG-A, and TGF-β1 protein expression compared to individual components or negative control group. Additionally, the CTX–MEL nanocomplex showed a significant increase in mRNA expression levels of Col1A1 as compared to individual compounds. In conclusion, the ion-pairing nanocomplex of CTX–MEL represents a promising carrier that can be topically applied to improve wound healing.

The Role of the BH4 Cofactor in Nitric Oxide Synthase Activity and Cancer Progression: Two Sides of the Same Coin

Cancer development is associated with abnormal proliferation, genetic instability, cell death resistance, metabolic reprogramming, immunity evasion, and metastasis. These alterations are triggered by genetic and epigenetic alterations in genes that control cell homeostasis. Increased reactive oxygen and nitrogen species (ROS, RNS) induced by different enzymes and reactions with distinct molecules contribute to malignant transformation and tumor progression by modifying DNA, proteins, and lipids, altering their activities. Nitric oxide synthase plays a central role in oncogenic signaling modulation and redox landscape. Overexpression of the three NOS isoforms has been found in innumerous types of cancer contributing to tumor growth and development. Although the main function of NOS is the production of nitric oxide (NO), it can be a source of ROS in some pathological conditions. Decreased tetrahydrobiopterin (BH4) cofactor availability is involved in NOS dysfunction, leading to ROS production and reduced levels of NO. The regulation of NOSs by BH4 in cancer is controversial since BH4 has been reported as a pro-tumoral or an antitumoral molecule. Therefore, in this review, the role of BH4 in the control of NOS activity and its involvement in the capabilities acquired along tumor progression of different cancers was described.

Fluvastatin-Loaded Emulsomes Exhibit Improved Cytotoxic and Apoptosis in Prostate Cancer Cells

Fluvastatin (FLV) is known to inhibit the 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA), which is over-expressed in various cancers. FLV has been reported to decrease cancer development and metastasis. However, because of low bioavailability, extensive first-pass metabolism and short half-life of FLV (1.2 h), it is not appropriate for clinical application. Therefore, FLV-loaded emulsomes were formulated and optimized using Box-Behnken experimental design to achieve higher efficiency of formulation. Antitumor activity of optimized FLV-loaded emulsomes was evaluated in prostate cancer cells using cell cytotoxicity, apoptotic activity, cell cycle analysis, and enzyme-linked immunosorbent assay. The FLV-loaded emulsomes exhibited a monodispersed size distribution with a mean particle size less than 100 nm as measured by zetasizer. The entrapment efficiency was found to be 93.74% with controlled drug release profile. FLV-EMLs showed a significant inhibitory effect on the viability of PC3 cells when compared to the free FLV (P < 0.0025). Furthermore, FLV-EMLs showed significant arrest in G2/M and increase in percentage of apoptotic cells as compared to free FLV. FLV-EMLs were more effective than free FLV in reducing mitochondrial membrane potential and increase in caspase-3 activity. These results suggesting that FLV-EMLs caused cell cycle arrest which clarifies its significant antiproliferative effect compared to the free drug. Therefore, optimized FLV-EMLs may be an effective carrier for FLV in prostate cancer treatment.

Piceatannol-Loaded Bilosome-Stabilized Zein Protein Exhibits Enhanced Cytostatic and Apoptotic Activities in Lung Cancer Cells

Piceatannol (PIC) is a naturally occurring polyphenolic stilbene, and it has pleiotropic pharmacological properties. Moreover, PIC has cytotoxic actions among various cancer cells. In this work, preparations of PIC-loaded bilosome-zein (PIC-BZ) were designed, formulated, and characterized, and the optimized PIC-BZ cytotoxic activities, measured as half maximal inhibitory concentration (IC₅₀), against lung cancer cell line was investigated. Box-Behnken design was utilized in order to examine the effect of preparation factors on drug entrapment and particle size. PIC-BZ showed a spherical shape after optimization, and its particle size was determined as 157.45 ± 1.62 nm. Moreover, the efficiency of drug entrapment was found as 93.14 ± 2.15%. The cytotoxic activity evaluation revealed that the adjusted formulation, which is PIC-BZ formula, showed a substantially smaller IC₅₀ versus A549 cells. Cell cycle analysis showed accumulation of cells in the G2-M phase. Moreover, it showed in the sub-G1 phase, a rise of cell fraction suggestion apoptotic improving activity. Increased early and late phases of apoptosis were demonstrated by staining of cells with annexin V. Furthermore, the cellular caspase-3 protein expression was significantly raised by PIC-BZ. In addition, the wound healing experiment confirmed the results. To conclude, compared to pure PIC, PIC-BZ demonstrated a higher cell death-inducing activity against A549 cells.