Decreased plasma superoxide scavenging activity in immunological disorders--carboxyethylgermanium sesquioxide (Ge-132) as a promoter of prednisolone

Interaction of Organogermanium Compounds with Saccharides in Aqueous Solutions: Promotion of Aldose-to-ketose Isomerization and Its Molecular Mechanism

This review discusses sugar isomerization with organogermanium compounds. Organogermanium compounds markedly increase the aldose-ketose (glucose-fructose or lactose-lactulose) isomerization ratio, double the initial reaction rate, and significantly reduce the base-catalyzed degradation of sugars. 1H-nuclear magnetic resonance analysis reveals that the affinity of organogermanium compounds with a 3-(trihydroxygermyl)propanoic acid (THGP) structure toward ketoses is 20-40 times stronger than that toward aldoses; thus, such organogermanium compounds form complexes more readily with ketoses than with aldoses. Stable ketose complexes, which contain multiple cis-diol structures and high fractions of furanose structures, suppress the reverse ketose-aldose reaction, thereby shifting the equilibrium toward the ketose side. These complexes also protect sugar molecules from alkaline degradation owing to the repulsion between anionic charges. The increased rate of the initial reaction in the alkaline isomerization process results from stabilizing the transition state by forming a complex between THGP and a cis-enediol intermediate. The cyclic pentacoordinate or hexacoordinate THGP structures give rise to a conjugated system of germanium orbitals, which is extended through dπ-pπ interactions, thereby improving the stability of the complex. Based on these results, we have developed a bench-scale lactulose syrup manufacturing plant incorporating a system to separate, recover, and reuse organogermanium poly-trans-[(2-carboxyethyl)germasesquioxane]. This manufacturing plant can be used as a model of an alkaline isomerization accelerator for continuous industrial production.

Potential of germanium-based compounds in coronavirus infection

The first germanium compounds which exhibited immunomodulatory and antiviral effects were sesquioxane-type germanates. To date, more than a dozen compounds containing germanium have been synthesized and are being actively studied. They include germanium carboxylates and citrates, complexes of germanium with resveratrol, daphnetin, mangiferin, chrysin, quercetin, ascorbic and nicotinic acids, amino acids, gamma-lactones, germanium-containing spirulina, yeast and others. Germanium-based compounds have shown the ability to influence the replication of various DNA/RNA viruses, stimulate the body's natural resistance, prevent the development of metabolic intoxication of various origin, increase the efficacy of vaccines, and prevent the development of excessive accumulation of reactive oxygen species, which plays a decisive role in the development of inflammatory response caused by a viral infection. It seems reasonable to say that germanium-based complex compounds effectively contribute to the preservation of high--energy bonds in the form of ATP, optimize the activity of metabolic processes by re-oxygenation, and exhibit antimicrobial activity. The purpose of this review is to summarize the pharmacological potential of various germanium-based compounds studied nowadays, taking into account their mechanisms of action, and to analyze their prospects in the development of integrated approaches in the prevention and treatment of SARS-CoV-2 infection.

Immune activation of Bio-Germanium in a randomized, double-blind, placebo-controlled clinical trial with 130 human subjects: Therapeutic opportunities from new insights

Germanium has long been considered a therapeutic agent with anticancer, antitumor, antiaging, antiviral and anti-inflammatory effects. Numerous clinical studies have explored the promising therapeutic effects of organic germanium on cancer, arthritis and senile osteoporosis. The immune activation property of organic germanium is considered the foundation of its various therapeutic effects. However, previous human clinical studies investigating immune activation with organic germanium compounds have certain limitations, as some studies did not strictly follow a randomized, double-blind, placebo-controlled design. To build a more clinically substantiated foundation for the mechanism underlying its immunostimulation, we structured by far the most rigorous clinical study to-date with a group of 130 human subjects to examine changes in immune profiles following germanium supplementation. We used Bio-Germanium, an organic germanium compound naturally synthesized via a yeast fermentation process. An 8-week randomized, double-blind, placebo-controlled study was conducted with 130 subjects with leukocyte counts of 4–8 (×10³/μL) divided into the Bio-Germanium group and the placebo group. Anthropometric measurements; blood collection; biochemical analysis; urinalysis; and natural killer cell activity, cytokine and immunoglobulin assays were conducted. Results showed the Bio-Germanium group exhibited NK cell activity increases at effector cell:target cell (E:T) ratios of 50:1, 10:1, 5:1 and 2.5:1 (12.60±32.91%, 10.19±23.88%, 9.28±16.49% and 7.27±15.28%, respectively), but the placebo group showed decreases (P<0.01). The difference in the IgG1 change from baseline to follow-up between the Bio-Germanium and placebo groups was significant (P = 0.044). Our results and earlier clinical study of Bio-Germanium confirm that Bio-Germanium acts as an effective immunostimulant by increasing the cytotoxicity of NK cells and activating immunoglobulin, B cells and tumor necrosis factor (TNF)-α (P<0.05). As we have added newly discovered clinical findings for germanium’s immunostimulation mechanism, we believe Bio-Germanium is a highly promising therapeutic agent and should certainly be further explored for potential development opportunities in immunotherapy.

Facile synthesis of unnatural β-germyl-α-amino amides via Pd(ii)-catalyzed primary and secondary C(sp3)–H bond germylation

Pd(ii)-Catalyzed direct C(sp³)–H germylation of α-AA derivatives with the assistance of a bidentate auxiliary for the efficient synthesis of β-germyl-α-amino amides is reported.

Carboxyethylgermanium sesquioxide (Ge-132) treatment during in vitro culture protects fertilized porcine embryos against oxidative stress induced apoptosis

Compared with the in vivo environment, porcine in vitro embryo-culture systems are suboptimal, as they induce oxidative stress via the accumulation of reactive oxygen species (ROS). High ROS levels during early embryonic development cause negative effects, such as apoptosis. In this study, we examined the effects of the antioxidant carboxyethylgermanium sesquioxide (Ge-132) during in vitro culture (IVC) on embryonic development in porcine in vitro fertilization (IVF) embryos. Zygotes were treated with different concentrations of Ge-132 (0, 100, 200 and 400 μg/ml). All of the Ge-132 treatment groups displayed greater total cell numbers after IVC (98.1, 98.5 and 103.4, respectively) compared with the control group (73.9). The 200 μg/ml Ge-132 treatment group exhibited significantly increased intracellular GSH levels compared with the control group, whereas the ROS generation levels decreased in Ge-132 dose-dependent manner (P < 0.05). The mRNA expression levels of the KEAP1 gene and proapoptotic genes BAX and CASPASE3 were lower in the Ge-132 treated blastocysts compared with the control group (P < 0.05). The percentages of apoptotic and necrotic cells in the Ge-132 treated embryos on day 2 (48 h) were significantly lower than the untreated embryos (9.1 vs. 17.1% and 0 vs. 2.7%, respectively). In the day 7 blastocysts, the percentages of apoptotic cells in 200 µg/ml Ge-132 treated group were lower compared to controls (1.6 vs. 2.5%). More KEAP1 protein was found to be localized in cytoplasm of the 200 μg/ml Ge-132 treated blastocysts, whereas KEAP1 protein was predominantly nuclei in the control blastocysts. These results indicate that the developmental competence of embryos cultured under Ge-132 treatment may be associated with KEAP1 signaling cascades involved in oxidative stress and apoptosis during porcine preimplantation embryo development.

Efficient Conversion of D-Glucose to D-Fructose in the Presence of Organogermanium Compounds

D-Glucose and D-fructose are isomers of commonly consumed monosaccharides. The ratio of conversion of D-glucose to D-fructose by glucose isomerase (xylose isomerase) is not more than 50 %. However, addition of an equimolar ratio of the organogermanium compound poly-trans-[(2-carboxyethyl)germasesquioxane] (Ge-132) or its derivative increases the conversion ratio to 80 %. In contrast, use of the Lobry de Bruyn–Alberda van Ekenstein transformation with heating results in a lower conversion ratio, less than 30 %, whereas addition of an equimolar concentration of Ge-132 or its derivative to this reaction mixture increases the ratio to 73 %. Therefore, in this study, we aimed to further analyze the affinity between organogermanium compounds (i.e., Ge-132 and its derivatives) and sugar using ¹H-nuclear magnetic resonance (NMR) spectrometry. For the dimethyl derivative of Ge-132, the complex formation ratios at 0.25 M (mixing ratio 1:1) were 19 and 74 % for D-glucose and D-fructose, respectively. Additionally, the complex formation constants between monosaccharides and Ge-132 were 1.2 and 46 M^-1 for D-glucose and D-fructose, respectively. The complex formation capacity was approximately 40-fold higher for D-fructose than for D-glucose. Therefore, we concluded that the high affinity for the product of isomerization may promote isomerization, and that promotion of sugar isomerization using organogermanium compounds is an effective method for conversion of D-glucose to D-fructose.

Antioxidant status after iloprost treatment in patients with Raynaud's phenomenon secondary to systemic sclerosis

Oxidative stress is involved in pathogenesis of Raynaud's phenomenon (RP), a hallmark of systemic sclerosis (SSc). Frequent episodes of ischemia-reperfusion may lead to release of free radicals and enhanced lipid peroxidation reflected by elevated levels of malondialdehyde (MDA). The failure of native antioxidants (Catalase [CAT], Superoxide dismutase [SOD], and Ceruloplasmin [CP]) might be crucial in endothelial cells damage in RP. Iloprost (IL) synthetic prostacyclin analogue is currently used in the treatment of SSc patients with RP. The objectives of this study were to compare the serum levels of MDA and CP, CAT and SOD activity in red blood cells hemolysate in SSc patients compared to healthy controls; and to study the effect of 5-days IL infusions on MDA and CP levels, and CAT and SOD activity in SSc patients with RP. Twelve SSc patients were treated with 50 mug IL for 5 days. Blood samples were taken before and after day 1st and after day 5th of IL infusions. Levels of CAT were measured according to the Aebi's method; SOD, according to the Misra and Fridovich method; MDA, according to Slater's method; and CP, according to Ravin's method. Activities of CAT (p < 0.001) and SOD (p < 0.04) were significantly reduced; levels of CP (p < 0.006) and MDA (p < 0.06) were raised in SSc compared to controls. IL infusions caused reduction in MDA (p < 0.0001) levels and enhanced production of SOD (p < 0.006) and CAT (p < 0.003). The levels of CP did not change (p = 0.48). Oxidant status in SSc patients with RP is impaired. Therapy with IL led to normalization of antioxidant activity. We suggest that CAT may be a sensitive and reliable laboratory marker of oxidative stress severity in RP. We found that IL, in addition to its vasoactive properties, has a potential to activate inner antioxidant system. Activation of inner antioxidant activity may explain long-term effect of IL instead of its very short half-life time.