Protective effects of glucosamine and its acetylated derivative on serum/glucose deprivation-induced PC12 cells death: Role of reactive oxygen species

Neuroprotective effects of alpha-lipoic acid on radiation-induced brainstem injury in rats

Background and purpose

Alpha-lipoic acid (ALA) is an antioxidant with radioprotective properties. We designed the current work to assess the neuroprotective function of ALA in the presence of oxidative stress induced by radiation in the brainstem of rats.

Experimental approach

Whole-brain radiations (X-rays) was given at a single dose of 25 Gy with or without pretreatment with ALA (200 mg/kg BW). Eighty rats were categorized into four groups: vehicle control (VC), ALA, radiation-only (RAD), and radiation + ALA (RAL). The rats were given ALA intraperitoneally 1 h before radiation and killed following 6 h, thereafter superoxide dismutase (SOD), catalase (CAT), malondialdehyde (MDA), and total antioxidant capacity (TAC) in the brainstem were measured. Furthermore, a pathological examination was carried out after 24 h, 72 h, and five days to determine tissue damage.

Findings/Results

The findings indicated that MDA levels in the brainstem were 46.29 ± 1.64 μM in the RAD group and decreased in the VC group (31.66 ± 1.72 μM). ALA pretreatment reduced MDA levels while simultaneously increasing SOD and CAT activity and TAC levels (60.26 ± 5.47 U/mL, 71.73 ± 2.88 U/mL, and 227.31 ± 9.40 mol/L, respectively). The greatest pathological changes in the rat's brainstems were seen in RAD animals compared to the VC group after 24 h, 72 h, and 5 days. As a result, karyorrhexis, pyknosis, vacuolization, and Rosenthal fibers vanished in the RAL group in three periods.

Conclusion and implications

ALA exhibited substantial neuroprotectivity following radiation-induced brainstem damage.

The effects of medical linear accelerator X-rays on human peripheral blood lymphocytes in the presence of glucosamine

Glucosamine is widely prescribed as a dietary supplement used to treat arthritis. In this study, the radioprotective ability of glucosamine was evaluated against radiation-induced genotoxicity and cytotoxicity in human peripheral blood lymphocytes. Blood samples were collected from five healthy male donors and were divided into four groups. Isolated lymphocytes and blood samples were treated with 10 µM of glucosamine for 2 h before exposure to 2 Gy radiation. The radioprotective potential of glucosamine was assessed by micronucleus assay, reactive oxygen species (ROS) level analysis, and flow cytometry. Irradiation significantly increased the micronuclei frequency as compared to the control group. Contrary to that pretreatment with glucosamine before irradiation significantly reduced the frequency of micronuclei. Furthermore, pretreatment with glucosamine significantly prevented the percentage of apoptotic lymphocytes. Also, glucosamine pretreatment significantly reduced the production of ROS in irradiated lymphocytes. This study shows glucosamine to be a potent radioprotector against radiation that induces DNA damage and apoptosis in human lymphocytes. Several additional in vivo and in vitro studies are needed before glucosamine can be considered as a radioprotective candidate in patients undergoing radiation therapy.

Possible synergic action of non-steroidal anti-inflammatory drugs and glucosamine sulfate for the treatment of knee osteoarthritis: a scoping review

BACKGROUND

Several studies have reported that glucosamine sulfate (GS) can improve knee osteoarthritis (OA) symptomatology. In parallel, the disease-modifying effects of non-steroidal anti-inflammatory drugs (NSAIDs) in knee OA have also been investigated. However, limited literature has reported the combined effect of GS and NSAIDs. The aim of this scoping review is to describe the scope and volume of the literature investigating the potential benefits and synergistic effect of a combination of GS and NSAIDs in patients with knee OA.

METHODS

PubMed and Embase were searched for studies published from inception through April 2022, evaluating the effects of the combination of GS and NSAIDs in OA patients, versus either treatment alone. Data are reported narratively.

RESULTS

Five studies were included in this review; 4 were randomized control trials and one was a prospective observational study. The duration of combination treatment was 6 to 12 weeks. The combination was compared to celecoxib in 2 studies, meloxicam in 1, etoricoxib in 1, and a conventional NSAID in 1 (ibuprofen or piroxicam). All 5 studies reported that in patients with knee OA, the combination of GS plus NSAID yielded a significantly greater benefit than single-agent therapy, in terms of outcomes including pain reduction, function, joint stiffness, and markers of inflammatory activity and cartilage degradation.

CONCLUSION

The 5 studies included in this scoping review all report a significantly greater clinical benefit with a combination of GS plus NSAID compared to either treatment alone. The evidence supports efficacy in reducing pain, improving function, and possibly regulating joint damage. However, further randomized trials with larger sample sizes are warranted to confirm these findings.

Neuroprotective and Proneurogenic Effects of Glucosamine in an Internal Carotid Artery Occlusion Model of Ischemia

Neuroprotective, antineuroinflammatory, and proneurogenic effects of glucosamine, a naturally occurring amino sugar, have been reported in various animal models of brain injury including cerebral ischemia and hypoxic brain damage. Given that clinical translation of therapeutic candidates identified in animal models of ischemic stroke has remained unsatisfactory in general, possibly due to inadequacy of existing models, we sought to study the effects of glucosamine in a recently developed, clinical condition mimicking mouse model of internal cerebral artery occlusion. In this model of mild to moderate striatal damage, glucosamine ameliorated behavioral dysfunction, rescued ischemia-induced striatal damage, and suppressed ischemia-induced upregulation of proinflammatory genes in striatal tissue. Further, in ex vivo neurosphere assay involving neural stem cells/neural progenitor cells from subventricular zone, glucosamine increased the number of large neurospheres, along with enhancing mRNA levels of the proliferation markers Nestin, NeuroD1, and Sox2. Lastly, coronal brain sections containing the striatal region with subventricular zone showed increased number of BrdU positive cells and DCX positive cells, a marker for newly differentiating and immature neurons, in glucosamine-treated ischemic mice. Cumulatively, the results confirming neuroprotective, antineuroinflammatory, and proneurogenic effects of glucosamine enhance drug repurposing potential of glucosamine in cerebral ischemia.

Glucosamine promotes seizure activity via activation of the PI3K/Akt pathway in epileptic rats

CONTEXT

Glucosamine is an amino monosaccharide with a small molecular weight and has a protective effect against various neurological diseases including multiple sclerosis and encephalomyelitis. Interestingly, low-dose glucosamine has exhibited anti-epilepsy activity. Recent studies have shown that the activation of the protein kinase B (Akt) signaling pathway may promote epilepsy. Glucosamine can increase the level of Akt phosphorylation in the brain tissue, which may aggravate epilepsy. Hence, we speculate that a higher dose of glucosamine may aggravate epilepsy via AKT signaling.

OBJECTIVE

To investigate the effect of glucosamine on the behavior and electrophysiology of epileptic rats through PI3K/Akt pathway.

METHODS

Glucose (2.0 g/kg) and glucosamine (0, 0.5, 1.0, and 2.0 g/kg) were added to 2 mL of drinking water, respectively. An acute seizure rat model of lithium-pilocarpine and PTZ-kindling were constructed to observe the effects of different doses of glucosamine on epileptic behavior and hippocampal electrical activity. Meanwhile, the changes in Akt were detected by western blot.

RESULTS

Epileptic seizures were induced by a single dose of pilocarpine or PTZ and 2.0 g/kg of glucosamine significantly prolonged the duration and severity of epileptic seizures, enhanced hippocampal electrical activity energy density, and increased phosphorylated AKT levels. A glucosamine dose of 2.0 g/kg also significantly increased the total onset energy density. Furthermore, 2.0 g/kg glucosamine facilitated the development of the chronic PTZ-kindling process.

CONCLUSIONS

Glucosamine may exacerbate acute and chronic epileptic seizures via activation of the PI3K/Akt pathway in rats with experimental epilepsy.

The inhibiting effect of glucosamine sulfate combined with loxoprofen sodium on chondrocyte apoptosis in rats with knee osteoarthritis

OBJECTIVES

To explore the efficacy of glucosamine sulfate (GS) combined with loxoprofen sodium (LS) in rats with knee osteoarthritis (KOA) and its effect on chondrocytes.

METHODS

We randomly assigned 40 SPF SD rats to normal group (NG), control group (CG), treatment group (TG), and model group (MG). CG and TG were processed with continuous irrigation of LS and GS. NG and MG were given normal saline. We collected 3 mL of venous blood from the rat's lower limb for the detection of serum IL-1β, IL-6, IL-8, and TNF-α by ELISA. Four weeks after irrigation, 5 rats in each group were randomly selected for anesthesia. The water content was detected, and the chondrocytes were collected. MTT assay was used to detect apoptosis, and Western blot (WB) to measure concentrations of Bax, Bcl-2, Caspase3, Caspase9, TLR4, and NF-kB.

RESULTS

The levels of IL-1 β, IL-6, IL-8, and TNF-α decreased in CG and TG, but increased in MG (P<0.05). After treatment, the expression of inflammatory factors was highest in MG (P<0.05).

CONCLUSIONS

GS combined with LS showed good efficacy in rats with knee osteoarthritis, which may be achieved by inhibiting the expression of inflammatory factors and knee chondrocyte apoptosis via the TLR4-NF-kB pathway.

Glucosamine reverses drug resistance in MRP2 overexpressing ovarian cancer cells

Glucosamine (GlcN), a natural amino sugar in human body, was reported to exhibit anticancer activity against some tumors. In the present study, we evaluated the cytotoxicity and multi-drug resistance (MDR) reversal activity of GlcN on resistant MRP2-overexpressing ovarian cancer A2780RCIS cells. The cytotoxicity and MDR reversal activity of GlcN on cancer cells were measured by MTT assay. The effects of GlcN on MRP1 and MRP2 mRNA expression and function were evaluated by qRT-PCR and flow cytometry, respectively. The cell migration capacity of ovarian cancer cells were assessed in the presence or absence of GlcN using wound healing migration assay. Furthermore, the effects of GlcN on the mRNA expression of E-cadherin, vimentin and α-smooth muscle actin as Epithelial-Mesenchymal Transition (EMT)-related markers were evaluated by qRT-PCR. Our results indicated that glucosamine reduced the proliferation of human ovarian cancer cell lines (A2780) and its cisplatin resistant variant (A2780RCIS) in a dose-dependent manner. The IC50 values for A2780RCIS cells treated with cisplatin in the presence of different concentrations of GlcN (0, 1, 2 and 3 mM) for 72 h were 44.463 ± 1.603, 35.17 ± 0.025, 22.25 ± 0.018, 17.78 ± 0.012 μM respectively. Also GlcN decreased the expression of MRP1 and MRP2 mRNA in ovarian cancer cells. Our results further demonstrated that although GlcN had no significant effects on the expression of studied EMT-related markers in invasive A2780RCIS cells, it was able to inhibit their migration in vitro. According to these findings, GlcN could effectively enhance cisplatin cytotoxicity in resistant A2780RCIS cells.

Glucosamine Protects Rat Bone Marrow Cells Against Cisplatin-induced Genotoxicity and Cytotoxicity

BACKGROUND AND OBJECTIVE

Glucosamine is a widely prescribed dietary supplement used in the treatment of osteoarthritis. In the present study, the chemoprotectant ability of glucosamine was evaluated against cisplatin-induced genotoxicity and cytotoxicity in rat bone marrow cells.

METHODS

Glucosamine was orally administrated to rats at doses of 75 and 150 mg/kg body weight for seven consecutive days. On the seventh day, the rats were treated with a single injection of cisplatin (5 mg/kg, i.p.) at 1h after the last oral administration. The cisplatin antagonistic potential of glucosamine was assessed by micronucleus assay, Reactive Oxygen Species (ROS) level analysis, hematological analysis, and flow cytometry.

RESULTS

Glucosamine administration to cisplatin-treated rats significantly decreased the frequencies of Micronucleated Polychromatic Erythrocytes (MnPCEs) and Micronucleated Normchromatic Erythrocytes (MnNCEs), and also increased PCE/(PCE+NCE) ratio in bone marrow cells. Furthermore, treatment of rats with glucosamine before cisplatin significantly inhibited apoptosis, necrosis and ROS generation in bone marrow cells, and also increased red blood cells count in peripheral blood.

CONCLUSION

This study shows glucosamine to be a new effective chemoprotector against cisplatin-induced DNA damage and apoptosis in rat bone marrow cells. The results of this study may be helpful in reducing the harmful effects of cisplatin-based chemotherapy in the future.