Role of biotransformation in the diazinon-induced toxicity in HepG2 cells and antioxidant protection by tetrahydrocurcumin

Ivermectin-induced toxicity in HepG2 cells and the protective effect of tetrahydrocurcumin and vitamin C

Ivermectin (IVM) is a semi-synthetic antiparasitic derived from abamectin, one of the natural avermectins. The liver promotes metabolism and excretion of IVM, representing a risk of toxicity to this organ. The use of antioxidants to alleviate damage caused by chemicals has been increasingly studied. Thus, the aim of this study was to evaluate the effects of IVM on HepG2 cells to elucidate the mechanisms related to its toxicity and the possible protection provided by tetrahydrocurcumin (THC) and vitamin C. HepG2 cells were treated with IVM (1-25 μM) for 24 and 48 h. IVM was cytotoxic to HepG2 cells, denoted by a dose-dependent decrease in cell proliferation and metabolic activity. In addition, IVM induced damage to the cell membrane at all tested concentrations and for both incubation times. IVM significantly decreased the mitochondrial membrane potential from concentrations of 5 μM (24 h) and 1 μM (48 h). Additionally, IVM showed a time- and dose-dependent decrease in cellular adenosine triphosphate levels. The levels of reduced glutathione were decreased in a time- and dose-dependent manner, while IVM stimulated the production of reactive oxygen and nitrogen species (RONS) at all tested doses, reaching rates above 50% following treatment at 7.5 μM (24 h) or 5 μM (48 h). Treatment with THC (50 μM) and vitamin C (50 μM) protected against IVM-induced cytotoxicity and RONS production. These results suggest that oxidative damage is involved in IVM-induced toxicity in HepG2 cells, and that THC and vitamin C can mitigate the toxic effects caused by the compound.

Cytoprotective effect of l-carnitine against mancozeb-induced oxidative damage in human erythrocytes

Mancozeb is a commonly used fungicide that protects crops from numerous fungal pathogens. However, due to its widespread application, mancozeb has emerged as a significant human health hazard. Mancozeb causes oxidative damage to human cells, including erythrocytes. In this study, we have investigated the cytoprotective potential of the dietary antioxidant, l-carnitine, on mancozeb-induced oxidative damage in human erythrocytes. Incubation of erythrocytes with 100 μM mancozeb for 24 h caused a substantial elevation of markers of hemoglobin, lipid and protein oxidation. Intracellular levels of reactive oxygen and nitrogen species were considerably increased, and the antioxidant defense system of erythrocytes was severely compromised. Several enzymes catalyzing vital metabolic processes in erythrocytes were significantly inhibited. Mancozeb damaged the plasma membrane, increasing osmotic fragility and cell lysis. Membrane damage resulted in morphological transformation of the normal biconcave erythrocytes to echinocytes and stomatocytes. Erythrocytes incubated with l-carnitine (100-750 μM) for 2 h prior to mancozeb treatment showed a marked reduction in oxidative damage. l-carnitine effectively neutralized free radicals and reactive species, thereby significantly diminishing oxidative stress. The activities of antioxidant and metabolic enzymes were also restored. Preincubation with l-carnitine stabilized the erythrocyte membrane and maintained its standard biconcave shape. Incubation of erythrocytes with l-carnitine alone did not alter any of the above parameters. Thus, l-carnitine can serve as an effective protectant against pesticide-induced cytotoxicity in human erythrocytes.

Naringenin's Neuroprotective Effect on Diazino-Induced Cerebellar Damage in Male Albino Rats, with Modulation of Acetylcholinesterase

BACKGROUND

Diazinon, a well-known organophosphorus compound, is recognized for its neurotoxic effects, primarily through the inhibition of acetylcholinesterase (AChE) and induction of oxidative stress.

AIM

This study evaluates the neuroprotective effects of naringenin, a citrus flavonoid, against diazinon-induced cerebellar damage in male albino rats.

MATERIALS AND METHODS

Twenty-four rats were divided into four groups: control, naringenin, diazinon, and diazinon with naringenin.

RESULTS

Histological examination revealed altered structures of Purkinje cells in the cerebellum of the diazinon group. Naringenin co-treatment significantly improved cerebellar histology and modulated oxidative stress markers by decreasing malondialdehyde (MDA) and increasing glutathione (GSH) and glutathione peroxidase (GPx) levels. Additionally, naringenin exhibited anti-inflammatory effects by decreasing nuclear factor-kappa B (NF-κB), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β) levels, while increasing interleukin-10 (IL-10). It also reduced apoptotic markers, including p53, Bax, caspase-9, caspase-8, and caspase-3, while increasing the anti-apoptotic marker Bcl-2. Furthermore, naringenin modulated AChE activity, leading to decreased acetylcholine levels and reduced neurotoxicity.

CONCLUSIONS

These findings suggest that naringenin's antioxidant, anti-inflammatory, and anti-apoptotic properties contribute to its neuroprotective role against diazinon-induced cerebellar damage.

Tetrahydrocurcumin exhibits neuroprotective effects by inhibiting neuron ferroptosis via activity of iPLA2β/p38 MAPK phosphorylation in rat TBI model

Ferroptosis characterized by iron-dependent lipid peroxidation induced by traumatic brain injury (TBI) is an important factor that aggravates diseases. Studies have shown that tetrahydrocurcumin (THC) has neuroprotective effects in brain injury. However, whether THC inhibits neurocyte ferroptosis after TBI and its mechanism remains unclear. To investigate this, a weight-drop model in rats and H2O2 induced oxidative stress model in SH-SY5Y cells were established, and THC was used for treatment. Immunohistochemical staining showed that iron deposition reached its peak at 8th day after TBI. We found that THC remarkably inhibited iron accumulation in the cortical cortex and corpus callosum, improved neurological damage, reduced acute cerebral edema, weight loss, oxidative stress, and inflammation. Furthermore, the activity of iPLA2β was significantly reduced, and phosphorylation of p38 was increased after TBI, while THC alleviated the decrease in iPLA2β activity and increase in the level of P-p38. It confirmed that THC effectively mitigated ferroptosis, while iPLA2β inhibitor s-BEL could reverse the effects of THC on ferroptosis in vivo and in vitro experiments. In addition, SB202190 which is an inhibitor of p38 could enhance THC protection and lessen formation of ferroptosis-related proteins in cells. In conclusion, these findings suggested that THC may promote neurological function recovery after TBI by inhibiting neuron ferroptosis via activity of iPLA2β/P-p38.

The anticancer potential of tetrahydrocurcumin-phytosomes against oral carcinoma progression

BACKGROUND

Herbal medicine combined with nanotechnology offers an alternative to the increasing burden of surgery and/or chemotherapy, the main therapeutics of oral carcinoma. Phytosomes are nano-vesicular systems formed by the interaction between phospholipids and phyto-active components via hydrogen bonding, exhibiting superior efficacy over pure phytocomponents in drug delivery.

METHODS

Tetrahydrocurcumin (THC)-phytosomes were prepared by thin film hydration method. After characterization, in vitro cytotoxicity, antiproliferative capacity, antioxidant potential and full apoptotic workup were paneled on oral squamous cell carcinoma (SCC4) in comparison with native THC-solution and cisplatin (3.58 µg/mL intravenous injection), as positive controls. In addition, we tested the three medications on normal oral keratinocytes and gingival fibroblasts to attest to their tissue-selectivity.

RESULTS

Successful preparation of THC-phytosomes using 1:1 molar ratio of THC to phospholipid exhibited significantly increased aqueous solubility, good colloidal properties, and complete drug release after one hour. On SCC4 cells, THC-phytosomes, at their dose-/time-dependency at ~ 60.06 µg/mL escalated cell percentages in the S-phase with 32.5 ± 6.22% increase, as well as a startling 29.69 ± 2.3% increase in apoptotic population. Depletion of the cell colonies survival to 0.29 ± 0.1% together with restraining the migratory rate by -6.4 ± 6.8% validated THC-phytosomes' antiproliferative capacity. Comparatively, the corresponding results of THC-solution and cisplatin revealed 12.9 ± 0.9% and 25.8 ± 1.1% for apoptosis and 0.9 ± 0.1% and 0.7 ± 0.08% for colony survival fraction, respectively. Furthermore, the nanoformulation exhibited the strongest immuno-positivity to caspase-3, which positively correlated with intense mitochondrial fluorescence by Mitotracker Red, suggesting its implication in the mitochondrial pathway of apoptosis, a finding further explained by the enormously high Bax and caspase-8 expression by RT-qPCR. Finally, the THC groups showed the lowest oxidative stress index, marking their highest free radical-scavenging potential among the test groups.

CONCLUSIONS

THC-phytosomes are depicted to be an efficient nanoformulation that enhanced the anticancer efficacy over the free drug counterpart and the conventional chemotherapeutic. Additionally, being selective to cancer cells and less cytotoxic to normal cells makes THC-phytosomes a potential candidate for tissue-targeted therapy.

The role of tetrahydrocurcumin in disease prevention and treatment

In recent decades, natural compounds derived from herbal medicine or dietary sources have played important roles in prevention and treatment of various diseases and have attracted more and more attention. Curcumin, extracted from the Curcumae Longae Rhizoma and widely used as food spice and coloring agent, has been proven to possess high pharmacological value. However, the pharmacological application of curcumin is limited due to its poor systemic bioavailability. As a major active metabolite of curcumin, tetrahydrocurcumin (THC) has higher bioavailability and stability than curcumin. Increasing evidence confirmed that THC had a wide range of biological activities and significant treatment effects on diseases. In this paper, we reviewed the research progress on the biological activities and therapeutic potential of THC on different diseases such as neurological disorders, metabolic syndromes, cancers, and inflammatory diseases. The extensive pharmacological effects of THC involve the modulation of various signaling transduction pathways including MAPK, JAK/STAT, NF-κB, Nrf2, PI3K/Akt/mTOR, AMPK, Wnt/β-catenin. In addition, the pharmacokinetics, drug combination and toxicology of THC were discussed, thus providing scientific basis for the safe application of THC and the development of its dietary supplements and drugs.

Comparison of Alternative Splicing Landscapes Revealed by Long-Read Sequencing in Hepatocyte-Derived HepG2 and Huh7 Cultured Cells and Human Liver Tissue

The long-read RNA sequencing developed by Oxford Nanopore Technologies provides a direct quantification of transcript isoforms, thereby making it possible to present alternative splicing (AS) profiles as arrays of single splice variants with different abundances. Additionally, AS profiles can be presented as arrays of genes characterized by the degree of alternative splicing (the DAS-the number of detected splice variants per gene). Here, we successfully utilized the DAS to reveal biological pathways influenced by the alterations in AS in human liver tissue and the hepatocyte-derived malignant cell lines HepG2 and Huh7, thus employing the mathematical algorithm of gene set enrichment analysis. Furthermore, analysis of the AS profiles as abundances of single splice variants by using the graded tissue specificity index τ provided the selection of the groups of genes expressing particular splice variants specifically in liver tissue, HepG2 cells, and Huh7 cells. The majority of these splice variants were translated into proteins products and appeal to be in focus regarding further insights into the mechanisms underlying cell malignization. The used metrics are intrinsically suitable for transcriptome-wide AS profiling using long-read sequencing.

Novel tetrahydrocurcumin integrated mucoadhesive nanocomposite κ-carrageenan/xanthan gum sponges: a strategy for effective local treatment of oral cancerous and precancerous lesions

Oral cancer is one of the leading causes of death worldwide. Oral precancerous lesions (OPL) are the precursors of oral cancer, with varying degrees of progression. Tetrahydrocurcumin (THC) is a major metabolite of curcumin with superior anticancer properties against various types of cancer. However, THC's clinical outcome is limited by its poor aqueous solubility. Herein, we developed novel mucoadhesive biopolymer-based composite sponges for buccal delivery of THC, exploiting nanotechnology and mucoadhesion for efficient prevention and treatment of oral cancer. Firstly, THC-nanocrystals (THC-NC) were formulated and characterized for subsequent loading into mucoadhesive composite sponges. The anticancer activity of THC-NC was assessed on a human tongue squamous carcinoma cell line (SCC-4). Finally, the chemopreventive activity of THC-NC loaded sponges (THC-NC-S) was examined in DMBA-induced hamster OPL. The selected THC-NC exhibited a particle size of 532.68 ± 13.20 nm and a zeta potential of -46.08 ± 1.12 mV. Moreover, THC-NC enhanced the anticancer effect against SCC-4 with an IC50 value of 80 µg/mL. THC-NC-S exhibited good mucoadhesion properties (0.24 ± 0.02 N) with sustained drug release, where 90% of THC was released over 4 days. Furthermore, THC-NC-S had a magnificent potential for maintaining high chemopreventive activity, as demonstrated by significant regression in the dysplasia degree and a decline in cyclin D1 (control: 40.4 ± 12.5, THC-NC-S: 12.07 ± 5.2), culminating in significant amelioration after 25 days of treatment. Conclusively, novel THC-NC-S represent a promising platform for local therapy of OPL, preventing their malignant transformation into cancer.

The novel hepatoprotective effects of silibinin-loaded nanostructured lipid carriers against diazinon-induced liver injuries in male mice

In the current study, silibinin-loaded nanostructured lipid carriers (Sili-NLCs) was synthesized, and the hepatoprotective effectiveness of Sili-NLCs against diazinon (DZN)-induced liver damage in male mice was evaluated. The emulsification-solvent evaporation technique was applied to prepare Sili-NLCs, and characterized by using particle size, zeta potential, entrapment efficacy (EE %), in vitro drug release behavior, and stability studies. In vivo, studies were done on male mice. Hepatotoxicity in male mice were induced by DZN (10 mg/kg/day, i.p.). Four groups treated with silibinin and Sili-NLCs with the same doses (100 and 200 mg/kg, p.o.). On 31th days, serum and liver tissue samples were collected. Alanine (ALT) and aspartate (AST) aminotransferase levels, oxidative stress biomarkers, inflammatory cytokines, and histopathological alterations were assessed. The Sili-NLCs particle size, zeta potential, polydispersity index (PDI), and EE % were obtained at 220.8 ± 0.86 nm, -18.7 ± 0.28 mV, 0.118 ± 0.03, and 71.83 ± 0.15%, respectively. The in vivo studies revealed that DZN significantly increased the serum levels of AST, ALT, hepatic levels of lipid peroxidation (LPO), and tumor necrosis factor-α (TNF-α), while decreased the antioxidant defense system in the mice's liver. However, Sili-NLCs was more effective than silibinin to return the aforementioned ratio toward the normal situation, and these results were well correlated with histopathological findings. Improvement of silibinin protective efficacy and oral bioavailability by using NLCs caused to Sili-NLCs can be superior to free silibinin in ameliorating DZN-induced hepatotoxicity in male mice.