Alpha lipoic acid reverses the negative effect of LPS on mouse spermatozoa and developmental competence of resultant embryos in vitro

Lipoic acid as a protective agent against lipopolysaccharide and other natural toxins: a comprehensive review

Alpha-lipoic acid, also known as lipoate or lipoic acid (LA), is naturally present in the mitochondria of cells, where it functions as a cofactor for dehydrogenase enzyme complexes. It has also been reported that LA is a potent antioxidant. Not only does it scavenge free radicals directly, but it can also regenerate other essential cellular antioxidants. LA exhibits various anti-inflammatory effects and offers protection to mitochondria. Numerous studies have assessed the potential protective effects of LA against natural toxins, including lipopolysaccharides, galactosamine, mycotoxins, snake venoms, and toxins derived from cyanobacteria and plants. In general, the results of these studies indicate that LA can be effective in mitigating various toxicities, primarily due to the previously mentioned capabilities. Furthermore, novel mechanisms have been proposed for LA against specific toxins, for example, direct inactivation of secretory phospholipase A2 in some snake venoms or enhancement of p-glycoprotein activity to prevent saxitoxin entry into the neuronal cells. However, the gaps in the available data from most animal experiments conducted to date have resulted in insufficient evidence to justify further clinical evaluations of the effects of LA on human poisoning cases. Consequently, more extensive research is required to address these gaps and fully realize the therapeutic potential of this valuable substance.

Effect of Alpha-Lipoic Acid on the Development, Oxidative Stress, and Cryotolerance of Bovine Embryos Produced In Vitro

Oxidative stress (OS) induced by an imbalance in reactive oxygen species (ROS) levels in vitro impairs embryonic development. Here, we assessed the effects of alpha-lipoic acid (ALA) in in vitro production media on OS reduction, embryonic development, and cryotolerance of bovine embryos. We evaluated the effects of adding different concentrations of ALA (2.5, 5, 10, and 25 μM) to in vitro maturation (IVM) or in vitro culture (IVC) medium on embryonic development. We also determined the effects of adding ALA (25 μM) to the IVM and IVC medium in the same routine on the development and quality of embryos, ROS levels, and cryotolerance. Embryos were produced in vitro using conventional protocols for each treatment. The inclusion of ALA in the IVM and IVC media did not affect the development or quality of embryos; however, it reduced ROS levels in grade II embryos and increased hatching after 12 h on day 7 in grade I embryos and on day 8 in grade II embryos after warming. These findings prompt questions regarding the potential of ALA in improving embryo metabolism, considering the initial embryo recovery in the first few hours of embryo warming.

Polyamines protect porcine sperm from lipopolysaccharide-induced mitochondrial dysfunction and apoptosis via casein kinase 2 activation

Bacterial contamination is an inevitable issue during the processing of semen preservation in pigs. As a prototypical endotoxin from Gram-negative bacteria in semen, lipopolysaccharide (LPS) undermines sperm function during liquid preservation. Spermine and spermidine could protect cells against LPS-induced injury, and the content of spermine and spermidine in seminal plasma is positively correlated with sperm quality. Thus, the present study aimed to clarify whether addition of spermine or spermidine is beneficial to porcine semen preservation and able to prevent LPS-induced sperm damage. The supplementation of spermine and spermidine in the diluent resulted in higher sperm motility, viability, acrosome integrity, and mitochondrial membrane potential (ΔΨm) after preservation in vitro at 17 °C for 7 d (P < 0.05). LPS-induced sperm quality deterioration, ΔΨm decline, cellular adenosine-triphosphate depletion, mitochondrial ultrastructure abnormality, mitochondrial permeability transition pore opening, phosphatidylserine (PS) translocation, and caspase-3 activation (P < 0.05). Interestingly, spermine and spermidine alleviated the LPS-induced changes of the aforementioned parameters and mitigated the decrease in the microtubule-associated protein light chain 3-II (LC3-II) to LC3-I ratio. Meanwhile, the α and β subunits of casein kinase 2 (CK2) were detected at the connecting piece and the tail. Significantly, addition of 4,5,6,7-tetrabromobenzotriazole, a specific CK2 inhibitor, counteracted the beneficial effects of spermine and spermidine on sperm quality, mitochondrial activity, and apoptosis. Together, these results suggest that spermine and spermidine improve sperm quality and the efficiency of liquid preservation of porcine semen. Furthermore, spermine and spermidine alleviate LPS-induced sperm mitochondrial dysfunction and apoptosis in a CK2-dependent manner.

Alpha-Lipoic Acid: Biological Mechanisms and Health Benefits

Alpha-lipoic acid (ALA) is a bioactive molecule with significant health effects. The biological action of ALA has been ascribed to the characteristic antioxidant properties of the oxidized form (ALA) and its reduced counterpart the dihydrolipoic acid (DHLA) system. The ALA/DHLA combination represents an ideal antioxidant since it can quench radicals, is able to chelate metals, is amphiphilic, and has no major adverse effects. This unique system is able to scavenge reactive oxygen species, exerting a major effect on tissue levels of reduced forms of other antioxidants, including glutathione. For this reason, ALA is also known as the "antioxidant of antioxidants". This review analyzes the antioxidant, anti-inflammatory, and neuroprotective effects of ALA and discusses its applications as an ameliorative tool for chronic diseases and those associated with oxidative stress. Results from in vitro and in vivo studies demonstrated that ALA modulates various oxidative stress pathways suggesting its application, alone or in combination with other functional substances, as a useful support in numerous conditions, in which the balance oxidant-antioxidant is disrupted, such as neurodegenerative disorders. Based on several successful clinical studies, it has been also established that oral ALA supplements are clinically useful in relieving the complications of diabetes and other disorders including cardiovascular diseases and nerve discomforts suggesting that ALA can be considered a useful approach to improving our health.

Alpha-linolenic acid alleviates the detrimental effects of lipopolysaccharide during in vitro ovine oocyte development

During the transition period and early lactation of ruminants with higher production, the reproductive organs are exposed to various stressors, like inflammation stimulators such as lipopolysaccharides (LPS), as a consequence of high concentrate consumption. In this study, we aimed to determine the probable potential of α-linolenic acid (ALA) in alleviating LPS-induced effects in ovine oocytes in vitro as well as the underlying controlling mechanisms. Different concentrations of LPS (0, 0.01, 0.1, 1, and 10 μg/mL) were added to the oocyte maturation medium to evaluate its effect on oocyte developmental competence. Likewise, different concentrations of ALA (0, 10, 50, 100, and 200 μM/mL) were added to the maturation medium to define its effects on oocyte developmental competence. Accordingly, a combination of ALA and LPS in a dose-dependent manner was added to the maturation medium to elucidate their effect on oocyte developmental competence and uncover any possible potential of ALA to alleviate the detrimental effect induced by the presence of LPS. The expressions of candidate genes were measured in mature oocytes treated either with ALA, LPS, or ALA plus LPS. Adding LPS to the maturation medium decreased the cleavage rate of the treated oocytes, and those oocytes reached the blastocyst stage at a lower rate. Adding ALA to the maturation medium in the presence of LPS alleviated the detrimental effects of LPS in a dose-dependent manner, which ultimately led to higher cleavage and blastocyst formation. A higher expression of Trim26, GRHPR, NDUFA, PGC-1α, SOD, CS, SDH, p53, and CAT was observed in LPS-treated oocytes compared with the ALA and control groups. Additionally, CS and CAT transcripts were down-regulated in oocytes in LPS plus ALA-treated group compared to that of the LPS-treated group. These findings revealed that ALA has the potential to alleviate the detrimental effects induced by LPS on in ovine oocytes during maturation in vitro. Thus, LPS-detrimental effect and ALA-preventing mechanisms seem to be regulated through the expression of genes involved in mitochondrial biogenesis and function, oxidative stress, and antioxidant systems.

Alpha-lipoic acid supplementation reverses the declining quality of oocytes exposed to cyclophosphamide

Cyclophosphamide (CY) is a chemotherapeutic drug that is commonly used to treat malignancies of the ovary, breast, and hematology, as well as autoimmune disorders. As a cofactor of mitochondrial multienzyme complexes, alpha lipoic acid (ALA) is well known for its antioxidant characteristics, which operate directly on the scavenging of reactive oxygen species (ROS) and indirectly on the intracellular recycling of other antioxidants. However, the underlying mechanisms through which CY exerts its toxic effects on meiosis and oocyte quality, as well as a viable approach for protecting oocyte quality and preserving fertility, remain unknown. In present study, immunostaining and fluorescence intensity quantification were applied to assess the effects of CY and ALA supplementation on the key processes during the oocyte meiotic maturation. Our results show that supplementing oocytes with ALA, a well-known antioxidant and free radical scavenger, can reverse CY-induced oocyte meiotic maturation failure. Specifically, we found that CY exposure caused oocyte meiotic failure by disrupting meiotic organelle dynamics and arrangement, as well as a prominently impaired cytoskeleton assembly. In addition, CY caused an abnormal distribution of mitochondrion and cortical granules, two indicators of oocyte cytoplasmic maturation. More importantly, we show that ALA supplementation effectively reverses CY-induced meiotic failure and oocyte quality decline by suppressing oxidative stress-induced DNA damage and apoptosis in oocytes. Collectively, our data reveal that ALA supplementation is a feasible approach to protect oocytes from CY-exposed deterioration, providing a better understanding of the mechanisms involved in chemotherapy-induced meiotic failure.

The effect of alpha-lipoic acid on sperm functions in rodent models for male infertility: A systematic review

In this systematic review, we assessed different studies to evaluate the protective effect of alpha-lipoic acid (ALA), as a multifaceted antioxidant, on sperm functions in rodent models. Four databases were searched to find papers reporting the effect of ALA treatment on animal models of male infertility. Up to December 2022, 11,787 articles were identified to explain the ALA protective effects. The included studies were evaluated for eligibility and risk of bias (CRD42022341370). Finally, we identified 23 studies that explain the effect of ALA on sperm functions in rodents. Among them, 15 studies indicated that ALA could restore sperm parameters. Six studies showed a significant reduction in sperm DNA damage by ALA treatment. Seventeen papers displayed the ALA antioxidant ability, and four studies indicated the ALA anti-inflammatory effect. Besides, thirteen studies displayed that ALA could modulate androgenesis. Also, eighteen studies revealed that ALA restored the testicular architecture to normal, and was also effective in restoring reproductive performance in two included studies. This systematic review provided cogent evidence for the protective effect of ALA in rodent models for male infertility by re-establishing spermatogenesis and steroidogenesis and maintaining redox and immune systems homeostasis.

Alpha-lipoic acid supplementation restores the meiotic competency and fertilization capacity of porcine oocytes induced by arsenite

Arsenite is known as a well-known endocrine disrupting chemicals, and reported to be associated with an increased incidence of negative health effects, including reproductive disorders and dysfunction of the endocrine system. However, it still lacks of the research regarding the beneficial effects of ALA on arsenite exposed oocytes, and the underlying mechanisms have not been determined. Here, we report that supplementation of alpha-lipoic acid (ALA), a strong antioxidant naturally present in all cells of the humans, is able to restore the declined meiotic competency and fertilization capacity of porcine oocytes induced by arsenite. Notably, ALA recovers the defective nuclear and cytoplasmic maturation of porcine oocytes caused by arsenite exposure, including the impaired spindle formation and actin polymerization, the defective mitochondrion integrity and cortical granules distribution. Also, ALA recovers the compromised sperm binding ability to maintain the fertilization potential of arsenite-exposed oocytes. Importantly, ALA suppresses the oxidative stress by reducing the levels of ROS and inhibits the occurrence of DNA damage along with apoptosis. Above all, we provide a new perspective for the application of ALA in effectively preventing the declined oocyte quality induced by environmental EDCs.

Review of lipoic acid: From a clinical therapeutic agent to various emerging biomaterials

Lipoic acid (LA), an endogenous small molecule in organisms, has been extensively used for the highly efficient clinical treatment of malignant diseases, which include diabetes, Alzheimer's disease, and cancer over the past seven decades. Tremendous progresses have been made on the use of LA in nanomedicine for the development of various biomaterials because of its unique biological properties and highly adaptable structure since the first discovery. However, there are few reviews thus far, to our knowledge, summarizing this hot subject of research of LA and its derived biomaterials. For this purpose, we present herein the first comprehensive summary on the design and development of LA and its derived materials for biomedical applications. This review first discusses the therapeutic use of LA followed by the description of synthesis and preclinical study of LA-derived-small molecules. The applications of various LA and poly (lipoic acid) (PLA)-derived-biomaterials are next summarized in detail with an emphasis on the use of LA for the design of biomaterials and the diverse properties. This review describes the development of LA from a clinical therapeutic agent to a building unit of various biomaterials field, which will promote the further discovery of new therapeutic uses of LA as therapeutic agents and facile development of LA-based derivates with greater performance for biomedical applications.

S100A4 promotes the progression of lipopolysaccharide-induced acute epididymitis in mice†

S100A4 has been suggested to be a critical regulator of tumor metastasis and is implicated in the progression of inflammation. The aim of this study is to investigate the expression and possible role of S100A4 in epididymitis. Using a mouse model of epididymitis induced by the injection of lipopolysaccharide (LPS) in the deferent duct, we found that LPS administration induced an upregulation of S100a4 transcription (P < 0.05) and a recruitment of S100A4 positive cells in the epididymal interstitium of wild type (WT) mice. Co-immunofluorescence showed that S100A4 was mainly expressed by granulocytes, CD4 lymphocytes, and macrophages. Deficiency of S100A4 reduced epididymal pathological reaction and the mRNA levels of the pro-inflammatory cytokines IL-1β and TNF-α (P < 0.01), suggesting that S100A4 promotes the progression of epididymitis. Furthermore, S100A4 deficiency alleviated the decline of sperm motility and rectified the abnormal expression of sperm membrane protein AMAD3, which suggested that in the progression of epididymitis, S100A4 aggravates the damage to sperm vitality. In addition, both Ki-67 marked cell proliferation and transferase-mediated dUTP-biotin nick end labeling detected cell apoptosis were reduced in S100a4-/- mice compared with WT mice after LPS treatment, indicating that S100A4 promotes both cell proliferation and cell apoptosis in epididymitis. Overall, these results demonstrate that S100A4 promotes the progression of LPS-induced epididymitis and facilitates a decline in sperm vitality, and its function may be related to the process of cell proliferation and apoptosis during inflammation.

Alpha-lipoic acid improves the maturation and the developmental potential of goat oocytes in vitro

Oxidative stress inevitably occurs during oocyte maturation in vitro. α-lipoic acid (α-LA) has a strong antioxidant capacity, but the effect of α-LA on parthenogenetic activation of oocytes was rarely reported. This study aims to investigate the effect of supplementing α-LA to in vitro maturation medium on the subsequent developmental ability of goat parthenogenetic embryos during oocytes maturation. In the study, the goat cumulus-oocyte complex was divided into the experimental (with 25 μmol/L α-LA) and the control (without α-LA) groups. Oxidase expression was measured using RT-qPCR. After 18-22 hr of maturation, the oocytes were then parthenogenetic activated. The total antioxidant capacity of embryos was measured after 0, 24, 48, 72 and 96 hr of culture. Rates of oocyte maturation and the rates of development for parthenogenetic embryos in the α-LA group were significantly improved by 7.88% (p < .05) and 5.41% (p < .05) compared with those in the control group, respectively. After 24 hr, the difference in total antioxidant capacity was extremely significant in both groups. An evident decrease in the control group and a minor decrease in the α-LA group were observed (p < .01). The ratio of inner cell mass cells to the total cell number of blastocysts in the α-LA group increased compared with that in the control group (p < .05) on day 8. α-LA significantly promoted the expression of SOD and GPX4 of parthenogenetic blastocysts and maturated oocytes. α-LA (25 μmol/L) improved the maturation rate and the developmental competence of the parthenogenetic activation of oocytes, which might be mediated by maintaining the total antioxidant ability of oocytes during the culture period.

The Relationship between Sperm Oxidative Stress Alterations and IVF/ICSI Outcomes: A Systematic Review from Nonhuman Mammals

Achieving high embryo quality following IVF and ICSI procedures is a key factor in increasing fertility outcomes in human infertile couples. While the male factor is known to underlie infertility in about 50% of cases, studies performed in human infertile couples have not been able to define the precise effect of sperm affectations upon embryo development. This lack of consistency is, in most cases, due to the heterogeneity of the results caused by the multiple male and female factors that mask the concrete effect of a given sperm parameter. These biases can be reduced with the use of animal gametes, being a good approach for basic researchers to design more homogeneous studies analyzing the specific consequences of a certain affectation. Herein, we conducted a systematic review (March 2020) that assessed the relationship between sperm oxidative stress alterations and IVF/ICSI outcomes in nonhumans mammals. The review was conducted according to PRISMA guidelines and using the MEDLINE-PubMed and EMBASE databases. Thirty articles were included: 11 performed IVF, 17 conducted ICSI, and two carried out both fertilization methods. Most articles were conducted in mouse (43%), cattle (30%) and pig models (10%). After IVF treatments, 80% of studies observed a negative effect of sperm oxidative stress on fertilization rates, and 100% of studies observed a negative effect on blastocyst rates. After ICSI treatments, a positive relationship of sperm oxidative stress with fertilization rates (75% of studies) and with blastocyst rates (83% of studies) was found. In conclusion, the present systematic review shows that sperm oxidative stress is associated with a significant reduction in fertilization rates and in vitro embryo development.

Astaxanthin Ameliorates the Lipopolysaccharides-Induced Subfertility in Mouse via Nrf2/HO-1 Antioxidant Pathway

The endotoxin lipopolysaccharide (LPS) exists in human semen, which is associated with reduced sperm quality. Studying the LPS-impaired spermatozoa motility and viability, and discovering effective therapeutic treatments have crucial importance. The time-course and dose-response experiments were performed to optimize the treatment dose and time of astaxanthin and LPS on mouse spermatozoa motility and viability. Sperm kinetics and morphology, reactive oxygen species production, in vitro fertilization, and developmental competence were examined to evaluate the protective effects of astaxanthin on spermatozoa after LPS exposure. The activity of nuclear factor erythroid 2-related factor-2/heme oxygenase 1 (Nrf2/HO-1) pathway was detected by quantitative reverse transcription polymerase chain reaction and Western blot. Astaxanthin improves LPS-impaired spermatozoa motility, viability, morphology, and activity; reduces LPS-induced spermatozoa oxidative stress; and alleviates LPS-impaired fertilization and embryo development through activating Nrf2/HO-1 antioxidant signaling pathway. Astaxanthin might be a potential treatment for LPS-induced subfertility.