The inhibition of heme oxigenase-1 (HO-1) abolishes the mitochondrial protection induced by sesamol in LPS-treated RAW 264.7 cells

3-methyl-1H-indol-1-yl dimethylcarbamodithioate attenuates periodontitis through targeting MAPK signaling pathway-regulated mitochondrial function

Periodontitis, the second most common oral disease, is primarily initiated by inflammatory responses and osteoclast differentiation, in which the MAPK signaling pathway and mitochondrial function play important roles. 3-methyl-1H-indol-1-yl dimethylcarbamodithioate (3o), a hybrid of indole and dithiocarbamate, was first synthesized by our group. It has shown anti-inflammatory activity against lipopolysaccharide-induced acute lung injury. However, it is not known if 3o can exert effects in periodontitis. In vitro study: LPS-induced macrophage inflammation initiation and a receptor activator of nuclear factor κB ligand-stimulated osteoclast differentiation model were established. Cell viability, inflammatory cytokines, osteoclast differentiation, the MAPK signaling pathway, and mitochondrial function before and after treatment with 3o were investigated. In vivo study: Alveolar bone resorption, inflammatory cytokine expression, osteoclast differentiation, and the underlying mechanisms were assessed in mice with periodontitis. Inflammatory cytokine expression and osteoclast differentiation appeared downregulated after 3o treatment. 3o inhibited the MAPK signaling pathway and restored mitochondrial function, including mitochondrial reactive oxygen species, mitochondrial membrane potential, and ATP production. Meanwhile, 3o reduced inflammation activation and bone resorption in mice with periodontitis, reflected by the decreased expression of inflammatory cytokines and osteoclasts, implying that 3o inhibited the MAPK signaling pathway and the mitochondrial oxidative DNA damage marker 8-OHdG. These results highlight the protective role of 3o in periodontitis in mice and reveal an important strategy for preventing periodontitis.

Sesaminol alters phospholipid metabolism and alleviates obesity-induced NAFLD

The prevalence of obesity-induced non-alcoholic fatty liver disease (NAFLD) and insulin resistance is increasing worldwide. We previously demonstrated that sesaminol increases thermogenesis in adipocytes, improves insulin sensitivity, and mitigates obesity in mice. In this study, we demonstrated that sesaminol increased mitochondrial activity and reduced ROS production in hepatocytes. Therefore, we delve into the metabolic action of sesaminol in obesity-induced NAFLD or metabolic dysfunction-associated liver disease (MAFLD). Here, we report that sesaminol induces OXPHOS proteins and mitochondrial function in vivo. Further, our data suggest that sesaminol administration reduces hepatic triacylglycerol accumulation and LDL-C levels. Prominently, the lipidomics analyses revealed that sesaminol administration decreased the major phospholipids such as PC, PE, PI, CL, and PS to maintain membrane lipid homeostasis in the liver upon HFD challenge. Besides, SML reduced ePC and SM molecular species and increased PA levels in the HFD-fed mice. Also, sesaminol renders anti-inflammatory properties and dampens fibrosis markers in the liver. Remarkably, SML lowers the hepatic levels of ALT and AST enzymes and alleviates NAFLD in diet-induced obese mice. The molecular docking analysis identifies peroxisome proliferator-activated receptors as potential endogenous receptors for sesaminol. Together, our study demonstrates plant lignan sesaminol as a potential small molecule that alters the molecular species of major phospholipids, including sphingomyelin and ether-linked PCs in the liver tissue, improves metabolic parameters, and alleviates obesity-induced fatty liver disease in mice.

Sesamol: A lignan in sesame seeds with potent anti-inflammatory and immunomodulatory properties

Inflammation is associated with the development and progression of a plethora of diseases including joint, metabolic, neurological, hepatic, and renal disorders. Sesamol, derived from the seeds of Sesamum indicum L., has received considerable attention due to its well-documented multipotent phytotherapeutic effects, including its anti-inflammatory and immunomodulatory properties. However, to date, no comprehensive review has been established to highlight or summarize the anti-inflammatory and immunomodulatory properties of sesamol. Herein, we aim to address this gap in the literature by presenting a thorough review encapsulating evidence surrounding the range of inflammatory mediators and cytokines shown to be targeted by sesamol in modulating its anti-inflammatory actions against a range of inflammatory disorders. Additionally, evidence highlighting the role that sesamol has in modulating components of adaptive immunity including cellular immune responses and Th1/Th2 balance is underscored. Moreover, the molecular mechanisms and the signaling pathways underlying such effects are also highlighted. Findings indicate that this seemingly potent lignan mediates its anti-inflammatory actions, at least in part, via suppression of various pro-inflammatory cytokines like IL-1β and TNFα, and downregulation of a multitude of signaling pathways including NF-κB and MAPK. In conclusion, we anticipate that sesamol may be employed in future therapeutic regimens to aid in more effective drug development to alleviate immune-related and inflammatory conditions.

Sesamol Loaded Albumin Nanoparticles: A Boosted Protective Property in Animal Models of Oxidative Stress

The current study evaluated the ability of sesamol-loaded albumin nanoparticles to impart protection against oxidative stress induced by anthracyclines in comparison to the free drug. Albumin nanoparticles were prepared via the desolvation technique and then freeze-dried with the cryoprotectant, trehalose. Albumin concentration, pH, and type of desolvating agent were assessed as determining factors for successful albumin nanoparticle fabrication. The optimal nanoparticles were spherical in shape, and they had an average particle diameter of 127.24 ± 2.12 nm with a sesamol payload of 96.89 ± 2.4 μg/mg. The drug cellular protection was tested on rat hepatocytes pretreated with 1 µM doxorubicin, which showed a 1.2-fold higher protective activity than the free sesamol. In a pharmacokinetic study, the loading of a drug onto nanoparticles resulted in a longer half-life and mean residence time, as compared to the free drug. Furthermore, in vivo efficacy and biochemical assessment of lipid peroxidation, cardiac biomarkers, and liver enzymes were significantly ameliorated after administration of the sesamol-loaded albumin nanoparticles. The biochemical assessments were also corroborated with the histopathological examination data. Sesamol-loaded albumin nanoparticles, prepared under controlled conditions, may provide an enhanced protective effect against off-target doxorubicin toxicity.

Sesamol prevents mitochondrial impairment and pro-inflammatory alterations in the human neuroblastoma SH-SY5Y cells: role for Nrf2

Mitochondria are a primary source and a target of reactive oxygen species (ROS). Increased mitochondrial production of ROS is associated with bioenergetics decline, cell death, and inflammation. Here we investigated whether a pretreatment (for 24 h) with sesamol (SES; at 12.5-50 µM) would be efficient in preventing the mitochondrial collapse induced by hydrogen peroxide (H₂O₂, at 300 µM) in the human neuroblastoma SH-SY5Y cell line. We have found that a pretreatment with SES at 25 µM decreased the effects of H₂O₂ on lipid peroxidation, protein carbonylation, and protein nitration in membranes obtained from the mitochondria isolated from the SH-SY5Y cells. In this regard, SES pretreatment decreased the production of superoxide anion radical (O₂^-•) by the mitochondria of H₂O₂-treated cells. SES also prevented the mitochondrial dysfunction induced by H₂O₂, as assessed by analyzing the activity of the complexes I and V. The H₂O₂-induced reduction in the production of adenosine triphosphate (ATP) was also prevented by SES. The levels of the pro-inflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α), as well as the activity of the transcription factor nuclear factor-κB (NF-κB) were downregulated by the SES pretreatment in the H₂O₂-challenged cells. Silencing of the nuclear factor erythroid 2-related factor 2 (Nrf2) transcription factor abolished the protection induced by SES regarding mitochondrial function and inflammation. Thus, SES depends on Nrf2 to promote mitochondrial protection in cells facing redox impairment.

Suppression of Mitochondria-Related Bioenergetics Collapse and Redox Impairment by Tanshinone I, a Diterpenoid Found in Salvia miltiorrhiza Bunge (Danshen), in the Human Dopaminergic SH-SY5Y Cell Line Exposed to Chlorpyrifos

Tanshinone I (T-I, C₁₈H₁₂O₃) is a diterpene found in Salvia miltiorrhiza Bunge (Danshen) and promotes cytoprotection in several experimental models. Chlorpyrifos (CPF) is an agrochemical that causes bioenergetics failure, redox impairment, inflammation, and cell death in animal tissues. Here, we investigated whether T-I would be able to prevent the consequences resulting from the exposure of the human dopaminergic SH-SY5Y cells to CPF. We found that a pretreatment with T-I at 2.5 µM for 2 h suppressed lipid peroxidation and protein carbonylation and nitration on the membranes of mitochondria extracted from the CPF-treated cells. Also, T-I reduced the production of radical superoxide (O₂^-•) by the mitochondria of the CPF-challenged cells. The production of nitric oxide (NO^•) and hydrogen peroxide (H₂O₂) was also decreased by T-I in the cells exposed to CPF. The CPF-induced decrease in the activity of the complexes I-III, II-III, and V was abolished by a pretreatment with T-I. Loss of mitochondrial membrane potential (ΔΨ_m) and reduction in the production of adenosine triphosphate (ATP) were also prevented by T-I in the CPF-treated cells. T-I also induced anti-inflammatory effects in the CPF-treated cells by decreasing the levels of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) and the activity of the nuclear factor-κB (NF-κB). Inhibition of heme oxygenase-1 (HO-1) or silencing of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) blocked the T-I-promoted mitochondrial protection and anti-inflammatory action. Overall, T-I depended on the Nrf2/HO-1 axis to prevent the deleterious effects caused by CPF in this experimental model.

Sesamol Alleviates the Cytotoxic Effect of Cyclophosphamide on Normal Human Lung WI-38 Cells via Suppressing RAGE/NF-κB/Autophagy Signaling

Cyclophosphamide (CYL) is a chemotherapeutic medication commonly used in managing various malignancies like breast cancer or leukemia. Though, CYL has been documented to induce lung toxicity. Mechanism of CYL toxicity is through oxidative stress and the release of damage-associated molecular patterns (DAMPs). Sesamol (SES) is a natural antioxidant isolated from Sesamum indicum and its effect against CYL-induced lung toxicity is not studied yet. This study aims to investigate whether SES could prevent any deleterious effects induced by CYL on lung using normal human lung cells, WI-38 cell line, without suppressing its efficacy. Cells were pretreated with SES and/or CYL for 24 h, then cell viability was estimated by MTS and trypan blue assays. The mode of cell death was determined by AO/EB staining. Additionally, caspase-3 level, oxidative stress, and inflammatory markers were evaluated by colorimetric and ELISA techniques. qRT-PCR was performed to evaluate RAGE, NF-κB, and Beclin-1 mRNA-expression. CYL-treated WI-38 cells developed a significantly increased cell death with enhanced oxidative and RAGE/NF-κb/Autophagy signaling, which were all attenuated after pretreatment with SES. Thus, we concluded that SES offered a protective role against CYL-induced lung injury via suppressing oxidative stress and RAGE/NF-κB/Autophagy signaling, which is a natural safe therapeutic option against CYL toxicities.

Sesamol Alleviates Airway Hyperresponsiveness and Oxidative Stress in Asthmatic Mice

Sesamol, isolated from sesame seeds (Sesamum indicum), was previously shown to have antioxidative, anti-inflammatory, and anti-tumor effects. Sesamol also inhibited lipopolysaccharide (LPS)-induced pulmonary inflammatory response in rats. However, it remains unclear how sesamol regulates airway inflammation and oxidative stress in asthmatic mice. This study aimed to investigate the efficacy of sesamol on oxidative stress and airway inflammation in asthmatic mice and tracheal epithelial cells. BALB/c mice were sensitized with ovalbumin, and received oral sesamol on days 14 to 27. Furthermore, BEAS-2B human bronchial epithelial cells were treated with sesamol to investigate inflammatory cytokine levels and oxidative responses in vitro. Our results demonstrated that oral sesamol administration significantly suppressed eosinophil infiltration in the lung, airway hyperresponsiveness, and T helper 2 cell-associated (Th2) cytokine expressions in bronchoalveolar lavage fluid and the lungs. Sesamol also significantly increased glutathione expression and reduced malondialdehyde levels in the lungs of asthmatic mice. We also found that sesamol significantly reduced proinflammatory cytokine levels and eotaxin in inflammatory BEAS-2B cells. Moreover, sesamol alleviated reactive oxygen species formation, and suppressed intercellular cell adhesion molecule-1 (ICAM-1) expression, which reduced monocyte cell adherence. We demonstrated that sesamol showed potential as a therapeutic agent for improving asthma.

Impaired heme metabolism in schizophrenia-derived cell lines and in a rat model of the disorder: Possible involvement of mitochondrial complex I

Accumulating data point to heme involvement in neuropsychiatric disorders. Heme plays a role in major cellular processes such as signal transduction, protein complex assembly and regulation of transcription and translation. Its synthesis involves the mitochondria, which dysfunction, specifically that of the complex I (Co-I) of the electron transport chain is involved in the pathophysiology of schizophrenia (SZ). Here we aimed to demonstrate that deficits in Co-I affect heme metabolism. We show a significant decrease in heme levels in Co-I deficient SZ-derived EBV transformed lymphocytes (lymphoblastoid cell lines - LCLs) as compared to healthy subjects-derived cells (n = 9/cohort). Moreover, protein levels assessed by immunoblotting and mRNA levels assessed by qRT-PCR of heme catabolic enzyme, heme Oxygenase 1 (HO-1), and protein levels of heme downstream target phosphorylated eukaryotic initiation factor 2-alpha (Peif2a/eif2a) were significantly elevated in SZ-derived cells. In contrast, protein and mRNA levels of heme synthesis rate limiting enzyme aminolevulinic acid synthase-1 (ALAS1) were unchanged in SZ derived LCLs. In addition, inhibition of Co-I by rotenone in healthy subjects-derived LCLs (n = 4/cohort) exhibited an initial increase followed by a later decrease in heme levels. These findings were associated with opposite changes in heme's downstream target and HO-1 level, similar to our findings in SZ-derived cells. We also show a brain region specific pattern of impairment in Co-I subunits and in HO-1 and PeIF2α/eIF2α in the Poly-IC rat model of SZ (n = 6/cohort). Our results provide evidence for a link between CoI and heme metabolism both in-vitro and in-vivo suggesting its contribution to SZ pathophysiology.