Anxiolytic, antioxidant, and neuroprotective effects of goji berry polysaccharides in ovariectomized rats: experimental evidence from behavioral, biochemical, and immunohistochemical analyses

Abstract

Recent studies have indicated that polysaccharides, the main component of the Lycium barbarum L. fruit, have beneficial effects (e.g., anxiolytic, antioxidant, and neuroprotective) on humans and rodents. However, the effects of different dosages of such polysaccharides on ovariectomized rats and their underlying mechanisms in the brain have not been evaluated in the literature. Here, we aimed to evaluate the effects of the high and low doses of polysaccharides obtained from Lycium barbarum fruits (HD-LBP and LD-LBP, respectively) on anxious behaviors via behavioral (using the OFT and EPM), biochemical (using ELISA), and immunohistochemical (using immunohistochemical staining) measures in detail. Two weeks after ovariectomy, the rats were randomly assigned to either the treatment conditions [control (DW, 3 mL/kg, p.o., per day), LD-LBP (20 mg/kg, 3 mL/kg, p.o., per day), HD-LBP (200 mg/kg, 3 mL/kg, p.o., per day), 17 β-ES (1 mg/kg, 3 mL/kg, p.o., per day), DZ(1 mg/kg, 3 mL/kg, p.o., per day)] or operation type [SHAM (pseudo-ovariectomized) and OVX (ovariectomized)]. The treatments were applied for 30 consecutive days, and then serum and brain tissue samples of all rats were collected. Biochemical (SOD, CAT, GPX, MDA, and 17 β-ES) and immunohistochemical (BDNF, SER, and apoptosis) analyses of the samples were performed as well. The rats administered HD-LBP and LD-LBP were less anxious than the control groups. The HD-LBP–treated rats had high levels of SOD and low levels of MDA in their serum samples. Moreover, HD-LBP and drug-treated groups had a high number of SER receptors and BDNF-positive cells and a low number of TUNEL-positive cells in their hippocampal brain tissues. The HD-LBP treatments decrease anxious behavior by increasing antioxidant enzyme activities, hippocampal SER and BDNF neurotransmitter levels and decreasing the TUNEL-positive cell count of ovariectomized rats. Given these findings, we suggest that menopause-induced symptoms of anxiety can be reduced by polysaccharides obtained from goji berry fruits, and that these findings will be beneficial for the production studies of natural herbal-origin antianxiety (anxiolytic) drugs in the future.

Neuroprotective effects of goji berry (Lycium barbarum L.) polysaccharides on depression-like behavior in ovariectomized rats: behavioral and biochemical evidence

“…In a recent study, we revealed positive benefits of L. barbarum methanol extract on rat behavior (12). We also showed that LBP decreased anxiety-like behavior of ovariectomized rats (14). LBP has neuroprotective properties such as reducing caspase-3 activation and apoptosis level in the hippocampus (15).…”

“…LD-LBP treatment may exert its antidepressant effects through the hippocampal mechanism as well as through the antioxidant mechanism. Other research showed the active ingredients of Hypericum perforatum (St John's wort) hypericin and hyperforin acting as 5-HT reuptake inhibitors in depression ( 14 , 15 ). Similar to IMP, LBP therapy may inhibit 5-HT reuptake by blocking SERT.…”

“…Oxidative stress is also related to decreased estrogen levels (9). This results in changes in neuromodulators and neurotransmitters such as brain-derived neurotrophic factor (BDNF) (11,12) and serotonin (5-HT) in the hippocampus (13)(14)(15). Furthermore, depression causes a decrease in hippocampal volume (16).…”

A review of the pharmacological action and mechanism of natural plant polysaccharides in depression

“…Neurotrophic factors (NTF), also referred to as neurotrophic agents, are a class of substances that exert a supportive influence on neuronal survival and facilitate neuronal regeneration and functional recovery. They are widely employed in the clinical management of Alzheimer’s disease, cerebral atrophy, Parkinson’s disease, and other neurological disorders ( Castrén et al, 2007 ; PehliVan Karakas et al, 2020 ). Brain-derived neurotrophic factors (BDNF), the most widely distributed neurotrophic factors in the CNS, plays important roles by activating both the prokinetic myosin-associated kinase (Trk) and p75 receptor.…”

Antitumor Mechanisms of Lycium barbarum Fruit: An Overview of In Vitro and In Vivo Potential

“…Among the wide range of plant-derived compounds that are garnering significant interest for their bioactive composition, exotic berry-type fruits stand out. In particular, various studies, conducted both in vitro and in vivo, have highlighted the impressive biological capabilities of L. barbarum , better known as goji berries [ 31 , 32 , 33 , 34 , 35 , 36 ].…”