Neuroinflammation and microglial expression in brains of social-isolation rearing model of schizophrenia

Schizophrenia is a psychiatric disorder with a global prevalence of approximately 0.45%. It is considered a mental illness, with negative symptoms, positive symptoms, and cognitive dysfunction. The outcomes of studies on the role of microglia and neuroinflammation have been conflicting. In addition, there is a poor understanding of the sex differences in microglial expression and neuroinflammation markers in the prefrontal cortex, hippocampus, and nucleus accumbens. Understanding the exact roles of neuroinflammation may guide the development of efficient therapeutic drugs that can address the negative, positive, and cognitive symptoms of the disease. We examined the effect of social isolation rearing on schizophrenia-related behaviours in male and female BALB/c mice. The social-isolation rearing protocol started on post-natal day (PND) 21, lasting for 35 days. Animals were assigned to four cohorts, consisting of five animals per group. On PND 56, animals were assessed for behavioural changes. We used enzyme-linked immunosorbent assays to investigate the expression of nuclear factor kappa B (NF-κB), tumour necrosis factor-α (TNF-α), and Interleukin-1β (IL-1β) in the hippocampus, nucleus accumbens, and prefrontal cortex. Immunohistochemistry was used to assess the expression of microglia in the three brain regions. Our study showed that isolation rearing led to increasing locomotion, heightened anxiety, depression, and a reduced percentage of prepulse inhibition. There was a significant increase (p < 0.05) in anxiety in the female isolation mice compared to male isolation mice. Furthermore, isolation rearing significantly increased microglia count (p < 0.05) in the hippocampus, nucleus accumbens, and prefrontal cortex, only in the male group. There was microglial hyper-activation as evident in the downregulation of CX3CR1 in both male and female social-isolation groups. Male social-isolation mice showed a significant increase (p < 0.05) in neuroinflammation markers only in the nucleus accumbens while the female social-isolation mice showed a significant increase (p < 0.05) in neuroinflammation markers in both the nucleus accumbens and hippocampus. The study showed that therapeutic interventions aimed at modulating CX3CR1 activity and reducing inflammation may be beneficial for patients with schizophrenia.

Cholecalciferol (VD3) Attenuates L-DOPA-Induced Dyskinesia in Parkinsonian Mice Via Modulation of Microglia and Oxido-Inflammatory Mechanisms

L-DOPA, the gold standard for managing Parkinson's disease (PD) is fraught by motor fluctuations termed L-Dopa-Induced Dyskinesia (LID). LID has very few therapeutic options. Hence, the need for preclinical screening of new interventions. Cholecalciferol (VD3) treatment reportedly improves motor deficit in experimental Parkinsonism. Therefore, the novel anti-dyskinetic effect of VD3 and its underlying mechanisms in LID was investigated. Dyskinesia was induced by chronic L-DOPA administration in parkinsonian (6-OHDA- lesioned) mice. The experimental groups: Control, Dyskinesia, Dyskinesia/VD3, and Dyskinesia/Amantadine were challenged with L-DOPA to determine the abnormal involuntary movements (AIMs) score during 14 days of VD3 (30 mg/kg) or Amantadine (40 mg/kg) treatment. Behavioral Axial, Limb & Orolingual (ALO) AIMs were scored for 1 min at every 20 mins interval, over a duration of 100 mins on days 1,3,7,11 and 14. Using western blot, striatum was assessed for expression of dopamine metabolic enzymes: Tyrosine Hydroxylase (TH) and Monoamine Oxidase-B (MAO-B); CD11b, BAX, P47phox, and IL-1β. Cholecalciferol significantly attenuated AIMs only on days 11 & 14 with maximal reduction of 32.7%. Expression of TH and MAO-B was not altered in VD3 compared with dyskinetic mice. VD3 significantly inhibited oxidative stress (P47phox), apoptosis (BAX), inflammation (IL-1β) and microglial activation (CD11b). VD3 showed anti-dyskinetic effects behaviorally by attenuating abnormal involuntary movements, modulation of striatal oxidative stress, microglial responses, inflammation, and apoptotic signaling; without affecting dopamine metabolic enzymes. Its use in the management of dyskinesia is promising. More studies are required to further evaluate these findings. Keywords: Cholecalciferol; L-DOPA-Induced Dyskinesia; Parkinson's Disease; Microglial; Oxidative stress; Inflammation.

Synergistic interaction between acetaminophen and L-carnosine improved neuropathic pain via NF-κB pathway and antioxidant properties in chronic constriction injury model

Background

Inflammation is known to underlie the pathogenesis in neuropathic pain. This study investigated the anti-inflammatory and neuroprotective mechanisms involved in antinociceptive effects of co-administration of acetaminophen and L-carnosine in chronic constriction injury (CCI)-induced peripheral neuropathy in male Wistar rats.

Methods

Fifty-six male Wistar rats were randomly divided into seven experimental groups (n = 8) treated with normal saline/acetaminophen/acetaminophen + L-carnosine. CCI was used to induce neuropathic pain in rats. Hyperalgesia and allodynia were assessed using hotplate and von Frey tests, respectively. Investigation of spinal proinflammatory cytokines and antioxidant system were carried out after twenty-one days of treatment.

Results

The results showed that the co-administration of acetaminophen and L-carnosine significantly (P < 0.001) increased the paw withdrawal threshold to thermal and mechanical stimuli in ligated rats compared to the ligated naïve group. There was a significant (P < 0.001) decrease in the levels of nuclear factor kappa light chain enhancer B cell inhibitor, calcium ion, interleukin-1-beta, and tumour necrotic factor-alpha in the spinal cord of the group coadministered with acetaminophen and L-carnosine compared to the ligated control group. Co-administration with acetaminophen and L-carnosine increased the antioxidant enzymatic activities and reduced the lipid peroxidation in the spinal cord.

Conclusions

Co-administration of acetaminophen and L-carnosine has anti-inflammatory effects as a mechanism that mediate its antinociceptive effects in CCI-induced peripheral neuropathy in Wistar rat.

Effect Of Caffeine and Adrenaline on Memory and Anxiety in Male Wistar Rats

The present study was designed to investigate the effects of caffeine and adrenaline administration on memory and anxiety in male rats. Rats weighing about 140-200g were used for the study. They were divided into three groups (4 animals per group). Study groups 1; a,b,c,d were healthy rats administered normal saline, 5,10 and 15mg/kg bw caffeine intraperitoneally (i.p.), respectively for 6 weeks. Study groups 2; a,b,c,d administered normal saline, 0.1, 0.2 and 0.31mg/kg bw adrenaline (i.p.), respectively for 6 weeks. Study groups 3; a,b,c,d administered normal saline, 5mg/kg caffeine (i.p.) + 0.1mg/kg adrenaline (i.p.), 10mg/kg Caffeine (i.p.) + 0.2mg/kg Adrenaline (i.p.) and 15mg/kg Caffeine (i.p.) + 0.3mg/kg Adrenaline (i.p.) respectively for 6 weeks. The result showed no significant difference in spatial memory across all animals in study groups 1: b,c,d when compared to control (a). Study groups 2: (b, c) showed increase in spatial memory when compared to control (a). 2(d) showed a significant (p<0.05) decrease. Study groups 3: b, c, d showed no significant difference in spatial memory when compared to control (a). Study groups 1: b, c showed significant (p<0.05) reduction in duration for the short and long term memory test when compared to control. Study groups 2 showed reduction in duration for both the long and short term memory test when compared to control Study groups 3 no significant (p<0.05) difference in short and long term memory test across all animals in the group. It was also observed that adrenaline enhanced short and long term memory and only high dose of adrenaline distorted spatial memory. Study groups 1; (b,c) showed significant (p<0.05) increase in the number of entries to the open arm of the elevated plus maze when compared to control (a). Study groups 2; (b), showed significant (p<0.05) increase in the frequencies of entries to the closed arm of the elevated plus maze when compared to control (a). Study groups 2; (d), showed a significant (p<0.05) decrease in the frequency of entries to the open and closed arm when compared to control (a). The study revealed that co- administration of caffeine and adrenaline led to elevation of mood, increased activity and reduction of anxiety in Wistar rats. In addition, it was observed that only high dose of adrenaline increased anxiety. It was also observed that caffeine and adrenaline enhanced short and long term memory and only high dose of adrenaline distorted spatial memory.

Saponins and flavonoids from Bacopa floribunda plant extract exhibit antioxidant and anti-inflammatory effects on amyloid beta 1-42-induced Alzheimer's disease in BALB/c mice

ETHNOPHARMACOLOGICAL RELEVANCE

Bacopa floribunda (BF), a locally available plant has been employed traditionally as memory enhancer in Southwestern, Nigeria. It has been utilized in traditional and Ayurvedic medicine as brain tonic for enhancing memory, anti-aging and forestalling series of psychological disorders. However, there is a dearth of scientific information on the mechanism(s) of action of important phytochemicals from BF extract on dementia.

AIM OF THE STUDY

Alzheimer's disease, the commonest form of dementia has been postulated to triple by 2050 as a result of increase in life expectancy. This study therefore assessed and compared the possible mechanism(s) of action of flavonoids and saponins from BF on Amyloid beta (Aβ1-42)-induced dementia in male BALB/c mice.

MATERIALS AND METHODS

Eighty (80) healthy BALB/c mice divided into 10 groups (n = 8) were given a single bilateral ICV injection of Aβ1-42 or normal saline. Graded doses of Saponins and flavonoids (50, 100 and 200 mg/kg) were used as treatment for 21 days. Hippocampal homogenates were assayed for the levels of antioxidants, oxidative stress and neuroinflammatory markers. In vitro antioxidant activity of flavonoids and saponins were equally assessed using standard procedures. The extent of microglial activation was quantified through immunohistochemistry procedure.

RESULTS

Aβ1-42 successfully caused a spike in hippocampal levels of MDA, IL1β, TNF-α including MPO levels and invariably decreased antioxidant activities. Likewise an increase in reactive microglia (microgliosis) was observed. However, crude saponins and flavonoids from BF were able to suppress microgliosis, oxidative stress and neuroinflammation induced by Aβ1- 42 and were observed to be more effective at higher doses of saponins (100 mg/kg and 200 mg/kg) and flavonoid (100 mg/kg).

CONCLUSIONS

Phytochemicals from BF efficiently exhibited dose dependent alleviation of some symptoms associated with Alzheimer's disease.

Chondroitin and glucosamine sulphate reduced proinflammatory molecules in the DRG and improved axonal function of injured sciatic nerve of rats

Neuropathic pain (NP) is an abnormality resulting from lesion or damage to parts of the somatosensory nervous system. It is linked to defective quality of life and often poorly managed. Due to the limited number of approved drugs, limited efficacy and side effects associated with the approved drugs, drugs or drug combinations with great efficacy and very minimal or no side effects will be of great advantage in managing NP. This study aimed at investigating the synergistic antinociceptive effects of the combination of glucosamine sulphate (GS) (240 mg/kg) and chondroitin sulphate (CS) (900 mg/kg) in chronic constriction injury (CCI)-induced neuropathy in rats. Forty-two Wistar rats were randomly distributed into seven groups (n = 6). Sciatic nerve was ligated with four loose ligatures to induce NP. Effects of drugs were examined on stimulus and non-stimulus evoked potentials, expression of dorsal root ganglia (DRG) pain modulators and structural architecture of DRG. Oral administration of GS and CS for 21 days reduced hyperalgesia, allodynia, sciatic nerve functional aberration and DRG pain modulators. Histopathology and immunohistochemistry revealed restoration of structural integrity of DRG. Our result showed that the combination of GS and CS produced antinociceptive effects by attenuating hyperalgesia, allodynia and downregulation of NP mediators. GS and CS additionally produced synergistic analgesic effect over its individual components.

Effects of co-administration of vitamin E and lithium chloride on chronic constriction injury-induced neuropathy in male Wistar rats: Focus on antioxidant and anti-inflammatory mechanisms

OBJECTIVES

This study investigated the antinociceptive effects of co-administration of lithium chloride (LiCl) and vitamin E (Vit E) on chronic constriction injury (CCI)-induced peripheral neuropathy in male Wistar rats. It further explored the anti-inflammatory and neuroprotective properties of LiCl and Vit E, which may be complementary to the antinociceptive effects of the two substances.

METHODS

Thirty-six male Wistar rats, 190.00 ± 10.00 g of body weight were randomly assigned to 6 experimental groups and administered with normal saline, Vit E, LiCl, or their combination, once daily for 21 days. CCI was used to induce neuropathic pain (NP) and mechanical allodynia was assessed using von Frey filaments and pinprick test. Open field maze (OFM) was used to assess the exploratory behavior. Biochemical parameters were assessed in the dorsal root ganglion after 21 days of treatment.

RESULTS

Mechanical allodynia was developed in rats following CCI. Co-administration of LiCl and Vit E synergistically reduced mechanical hyperalgesia in rats which were significantly different compared with the single administration of either Vit E or LiCl. Combined doses of Vit E and LiCl significantly increases the explorative behavior in the OFM. CCI increased malondialdehyde (MDA), tumor necrotic factor-alpha (TNF-α), calcitonin gene-related polypeptide, calcium ion (Ca2+ ), and reduced superoxide dismutase (SOD) activities. Co-administration of LiCl and Vit E significantly reduced MDA, TNF-α, but increased SOD compared with ligated control.

DISCUSSION

The findings revealed that the synergistic effects of the co-administration of Vit E and LiCl in ameliorating NP are mediated by their anti-inflammatory and antioxidant properties.

Selenium reduces nociceptive response in acute 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced neurotoxicity

The potential of Se to alleviate pain associated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity was investigated.

Swiss mice were intraperitoneally injected with MPTP (20 mg/kg) 4 times with an interval of 2 h in 1 day. Seven days after MPTP injection, the mice (n = 5 mice per group) were randomly assigned to groups: MPTP-, DOPA (50 mg/kg)-, Se4 (0.4 mg/kg)-, Se6 (0.6 mg/kg)-, DOPA+Se4-, and DOPA+Se6-treated groups were compared with controls. MPTP mice were treated for seven days; thereafter, motor-coordination and nociceptive-motor reactions were assessed. Pro-inflammatory cytokines (IL-1β, IL-6 and TNFα), and selected pain biomarkers (substance P (SP), glutamate and β-endorphin) were assessed in the serum and the substantial nigra pars compacta (SNpc).

Motor activity was increased slightly by Se (0.6 or 0.4 mg/kg) vs. MPTP (10.48 ± 2.71 or 11.81 ± 1.28 s vs. 3.53 ± 0.06 s respectively) but considerably increased by DOPA (50 mg/kg) vs. MPTP (50.47 ± 3.06 s vs. 3.53 ± 0.06 s respectively). Se and DOPA increased nociceptive threshold but Se alone reduced both serum and SN pro-inflammatory cytokines. Se modulates SP while DOPA modulates SP and glutamate in the SNpc of mice treated with MPTP.

Se suppressed pro-inflammatory cytokines and restored the basal pain biomarkers in the SNpc of mice treated with MPTP. Se requires further study as analgesic adjuvant.

Chondroitin sulfate produces antinociception and neuroprotection in chronic constriction injury-induced neuropathic pain in rats by increasing anti-inflammatory molecules and reducing oxidative stress

OBJECTIVES

Damage to the peripheral and central nervous system lead to Neuropathic pain (NP) which is a widespread and devitalizing condition. chondroitin sulfate (CS), has been used in managing joint pain and osteoarthritis. In this study, the effectiveness of CS on NP induced by chronic constriction injury (CCI) is examined.

METHODS

Thirty Wistar rats were distributed at random into six groups (n = 5). Sciatic nerve ligation was carried out by encircling the nerve with four loose ligatures to induce NP. Allodynia (cold and mechanical) and heat hyperalgesia were assessed using Acetone, von Frey filament and Hot plate tests. CCI induction resulted to NP, prominent from the 3rd day after surgery. Structural architecture of sciatic nerves was evaluated via histological examination of the transverse section of the nerves.

RESULTS

Oral administration of CS (600 mg/kg and 900 mg/kg for 21 days) resulted in significant (P < 0.05) inhibition of allodynia (cold and mechanical) and thermal hyperalgesia. Lipid peroxidation, tumor necrosis factor-α (TNF-α), calcitonin gene related peptide (CGRP), C reactive protein (CRP), and oxidative stress were attenuated by CS. CS also improved interleukin (IL)-6, nitric oxide (NO), total antioxidant capacity (TAC).

CONCLUSION

These findings suggest that CS attenuates allodynia, and thermal hyperalgesia induced by CCI by downregulating TNF-α, CRP, CGRP, oxidative enzymes, and upregulating IL-6, NO, and TAC. Nociceptive behavioral studies and histological findings showed significant improvement in the CS treated groups compared to CCI rats. These findings are responsible for the beneficial effect of CS in NP.

Streptozotocin-induced type 1 and 2 diabetes in rodents: a model for studying diabetic cardiac autonomic neuropathy

Background

Several animal models are continually being developed to study diabetic complication. Several conflicting regimen for diabetes induction exist in the literature with varying dose strength and regimen for different study interest in diabetes. This study aims to show the effect of high dose streptozotocin (STZ) on the one hand compared with multiple low doses after high fat diet induction on diabetic cardiac autonomic neuropathy (DCAN).

Methodology

Eighty-four Wistar rats were used to demonstrate DCAN induction using 2 approaches one for T1DM (STZ 50mg/kg) and the other for T2DM (HFD for 8 weeks with STZ 25mg/Kg daily for five days). DCAN features were assessed using invasive biomarkers, histology patterns and cardiac nerve densities.

Results

Diabetes induction rate was 76% and 89% in T1DM and T2DM model respectively. T1DM group had significant weight loss, reduced c-peptide, and insulin level post induction. The T2DM additionally showed significantly higher total cholesterol and Homeostatic model assessment (HOMA) compared with control. Serum levels of catecholamine, choactase, nerve growth factor and cardiac nerve density confirms development of DCAN.

Conclusion

High single dose of STZ and HFD with multiple low doses of STZ may be recommended for DCAN study in T1DM and T2DM rat model respectively.

Antinociceptive effects of lead acetate in sciatic nerve chronic constriction injury model of peripheral neuropathy in male Wistar rats

The toxicological effects of lead and its compounds have overshadowed its possible health beneficial effects. Currently, the success rate for treating neuropathic pain has been very low. This study investigated the antinociceptive effects of orally administered low dose lead acetate in sciatic nerve ligated Wistar rats. Thirty Wistar rats randomly divided into five groups were used for this study. Chronic constriction injury (CCI) was used to induce neuropathic pain in Wistar rats. Allodynic and hyperalgesic signs were investigated using von Frey filaments and hotplate, respectively. Morris water maze test was used to assess the memory functions of the rats. The study revealed that oral administration of low-dose lead acetate significantly (p < 0.05) increased pain thresholds of ligated rats. CCI enhanced memory function in Wistar rats which was significantly decreased following lead acetate administration. The findings suggest that lead acetate possesses antinociceptive effects in peripherally induced neuropathic pain model in Wistar rats.

Vitamin D attenuated 6-OHDA-induced behavioural deficits, dopamine dysmetabolism, oxidative stress, and neuro-inflammation in mice

Background: L-DOPA, the predominant therapy for Parkinson's disease (PD) is associated with motor deficits after prolonged use. The nigrostriatal tract, a primary target of neurodegeneration in PD, contains abundant Vitamin-D receptors, suggesting a potential role for VD in the disease. Therefore, we tested the impact of Vitamin D3 (VD3) in a mouse model of PD.Methods: PD was induced in adult male C57BL6 mice by a single intrastriatal injection of 6-hydroxydopamine. Two weeks post lesion, these mice received injections of a vehicle, VD3, L-DOPA, or a combination of VD3/L-DOPA and compared with sham controls. Treatment lasted three weeks, during which motor-cognitive neurobehaviour was assessed. Five weeks post lesion, brains were collected and striatal levels of the following proteins assessed: tyrosine hydroxylase (TH), dopamine decarboxylase (DDC), monoamine oxidase (MAO-B), Catechol-O-methyl transferase (COMT), dopamine transporter (DAT), brain-derived neurotrophic factor (BDNF), microglia marker (CD11b), inflammation (IL-1β), apoptotic signaling (BAX) and oxidative stress (p47phox).Results: Treatment with VD3 attenuated behavioural deficits induced by 6-OHDA, protein associated with dopamine metabolism and biomarkers of oxidative stress. VD3 significantly increased contralateral wall touches, exploratory motor and cognitive activities. VD3 significantly enhanced the expression of TH, DAT, BDNF, while significantly reducing expression of MAO-B, CD11b, IL-I β and p47phox.Conclusion: VD3 reversed some of the 6-OHDA induced changes in proteins involved in modulating the dopamine system, behavioural deficits and oxidative stress biomarkers. The data suggests that VD3 might be beneficial in reducing L-DOPA dosage, thereby reducing problems associated with dosage and prolonged use of L-DOPA in PD management.

Bromelain: A Review on its Potential as a Therapy for the Management of Covid-19

Coronavirus Disease 2019 is a wide-spreading severe viral disease caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-COV-2) virus that needs to be urgently eradicated. SARS-COV-2 has infected millions of people worldwide and results in more than three hundred thousand deaths. Several repurposed drugs have failed to successfully eradicate the infection. Multiorgan failure caused by pronounced inflammation and systemic coagulation accounts for severe complications and death associated with diseases. Bromelain appears to be a potential candidate that may be used to inhibit or prevent the symptoms of the diseases. Its anti-inflammatory and anticoagulatory properties make it a potential agent that may slow the progression of the disease. In this review, we highlighted the beneficial effects of bromelain based on both experimental and clinical evidence that make bromelain a good candidate for the treatment of symptoms of CoVID-19 infection.

Heart rate variability indices, biomarkers, and cardiac nerve density: Independent surrogate markers for diagnosis of diabetic cardiac autonomic neuropathy in type 2 diabetes mellitus animal model

OBJECTIVES

Heart rate variability (HRV) has been shown to represents a promising quantitative marker of autonomic activity. Studies have shown that diabetic patients and animal models have derangements in certain biochemical parameters with reduced cardiac nerve density following development of diabetic cardiac autonomic neuropathy (DCAN). This study, therefore, aims to correlate HRV indices, cardiac histology, and cardiac nerve density with selected biochemical markers in the DCAN rat model using high fat diet (HFD) and streptozotocin (STZ) induction.

METHODS

DCAN was induced in Wistar rats using HFD for 8 weeks with 25 mg/kg STZ daily for 5 days. DCAN features were then assessed using Holter electrocardiography (ECG), invasive biomarkers, and cardiac histology.

RESULTS

DCAN group had significantly higher advanced glycated end product levels (P < 0.0001), noradrenaline (P = 0.010), and insulin resistance (P = 0.016) compared with controls. The level of antioxidants, sorbitol dehydrogenase activity (P = 0.009), nerve growth factors (P < 0.0001), and choline acetyl-transferase (P = 0.031) was, however, significantly reduced. Furthermore, HRV indices which were also reduced with DCAN induction correlated significantly with levels of biomarkers and cardiac nerve density.

CONCLUSION

HRV is a cheap and easy tool for assessing DCAN that significantly correlates with markers of autonomic activity. Holter ECG and HRV evaluation should be considered early in patients with diabetes.

Antinociceptive and neuroprotective effects of bromelain in chronic constriction injury-induced neuropathic pain in Wistar rats

Background

The continuous search for a novel neuropathic pain drug with few or no side effects has been a main focus of researchers for decades. This study investigated the antinociceptive and neuroprotective effects of bromelain in sciatic nerve ligation-induced neuropathic pain in Wistar rats.

Methods

Forty-eight Wistar rats randomly divided into eight groups comprised of six animals each were used for this study. Peripheral neuropathy was induced via chronic constriction of the common sciatic nerve. Thermal hyperalgesic and mechanical allodynia were assessed using a hotplate and von Frey filaments, respectively. The functional recovery and structural architecture of the ligated sciatic nerve were evaluated using the sciatic functional index test and a histological examination of the transverse section of the sciatic nerve. The neuroprotective effects of bromelain were investigated in the proximal sciatic nerve tissue after 21 days of treatment.

Results

Bromelain significantly (P < 0.05) attenuated both the thermal hyperalgesia and mechanical allodynic indices of neuropathic pain. There were improvements in sciatic function and structural integrity in rats treated with bromelain. These rats showed significant (P < 0.05) increases in sciatic nerve nuclear transcription factors (nuclear factor erythroid-derived-2-related factors-1 [NrF-1] and NrF-2), antioxidant enzymes (superoxide dismutase and glutathione), and reduced membrane-lipid peroxidation compared with the ligated control group.

Conclusions

This study suggest that bromelain mitigated neuropathic pain by enhancing the activities of nuclear transcription factors (NrF-1 and NrF-2) which increases the antioxidant defense system that abolish neuronal stress and structural disorganization.

Bromelain reversed electrolyte imbalance in the chronically constricted sciatic nerve of Wistar rats

Derangement of electrolyte in the sensory nervous system has been attributed to the development and maintenance of hyperalgesic and allodynic symptoms in painful neuropathy. This study investigated the effect of bromelain on electrolyte imbalance in chronically constricted sciatic nerve of rats (a model of neuropathic pain). Forty Wistar rats, divided into five groups of eight animals each were used for this study. von Frey filaments, tail immersion and acetone spray tests were used to assessed allodynic and thermal hyperalgesic symptoms in the Wistar rats. Sodium ion (Na⁺), potassium ion (K⁺), calcium ion (Ca²⁺) and chloride ion (Cl^-) concentrations as well as sodium-potassium and calcium electrogenic pump (Na-K ATPase and Ca ATPase, respectively) activities were estimated using spectrophotometry techniques. Bromelain significantly (p < 0.05) reversed elevation of Na⁺ and Ca²⁺ concentration compared with sciatic nerve chronic constriction injury (snCCI) group (35.68 ± 1.71 vs 44.46 ± 1.24 mg/ml/mg protein and 1.06 ± 0.19 vs 6.66 ± 0.03 mg/ml/mg protein, respectively). There were also significant (p < 0.05) increases in the level of K⁺ (0.84 ± 0.02 vs 0.36 ± 0.05 mg/ml/mg protein) and Cl^- (18.51 ± 0.29 vs 15.82 ± 0.21 mg/ml/mg protein). Bromelain reduced the activities of Ca²⁺ electrogenic pumps significantly compared with snCCI. This study therefore suggests that bromelain mitigated electrolyte imbalance in chronic constricted injury of the sciatic nerve implying that this may be an important mechanism for the anti-nociceptive effect of bromelain.

Cuprizone toxicity and Garcinia kola biflavonoid complex activity on hippocampal morphology and neurobehaviour

Cuprizone-induced neurotoxicity has been employed to study the biology of remyelination in experimental models of multiple sclerosis. This study was aimed at determining the role of kolaviron, a biflavonoid from Garcinia kola, in mitigating the damaging effects of cuprizone on behaviour and the hippocampus. Twenty-four male albino mice aged 6–8 weeks were categorised into 4 equal groups: Group A (Control) received regular diet; Group B received 200 mg/kg/d of kolaviron in addition to their regular diet; Group C received 0.2% cuprizone diet only, while Group D received both kolaviron and cuprizone diet. The treatment lasted for 35 days after which behavioural tests (Morris water maze, Y maze and open field tests) were conducted and brain tissues were processed for histology, histochemistry (Nissl staining), immunohistochemistry (glial fibrillary acidic protein) and biochemistry (malondialdehyde, superoxide dismutase and glutathione peroxidase). Results showed that cuprizone toxicity led to weight loss, impairment in memory and exploratory drive, oxidative stress, chromatolysis and reactive astrocytosis; meanwhile administration of kolaviron prevented cuprizone-induced weight loss, memory decline, oxidative stress and neuromorphological alterations. In conclusion, administration of kolaviron might be useful in limiting the effects of cuprizone toxicity on the morphology and functions of the hippocampus.

A Study of Pain Threshold, Interleukins and NLR in Diabetic Polyneuropathy in a Selected Nigerian Population

Pain serves a protective function and is often lost in chronic conditions such as painful diabetic neuropathy (PDN).This has been reported to be associated with ongoing inflammation. This study aims to investigate an association betweenbody immune responses, neutrophil-lymphocyte ratio (NLR) and pain perception in DPN patients. Sixty volunteers wererecruited for the study. 30 control and 30 diagnosed DPN patients (used Biothesiometer). All subjects were trained andinformed consents were obtained. The pain threshold was significantly (p<0.05) lower in DPN (23.48±1.19 sec) comparedto control group (30.38±1.9 sec), there was significant lower NLR in DPN (1.27±0.09) compared to control group (1.93±0.1)and the serum level of IL6 (15.31±0.85 pg/ml) in DPN was significantly higher compared to control group (11.9±0.15 pg/ml),likewise the serum level of IL10 (13.26±2.78 pg/ml) in DPN is significantly higher compared to control group (6.59±1.07pg/ml). This study showed that hyperalgesia seen in patients with DPN was independent of increased NLR, and increasedIL6 & IL10 seen in this group of patients indicates need to further explore the role of immunological response in thepathogenesis and progression of DPN.

Effects of acetone extract of Cola nitida on brain sodium-potassium adenosine triphosphatase activity and spatial memory in healthy and streptozotocin-induced diabetic female Wistar rats

Background This study was carried out to investigate the effects of acetone extract of Cola nitida on brain Na+/K+-ATPase activity and spatial memory of healthy and streptozotocin (STZ)-induced diabetic female Wistar rats. Methods Forty-two female Wistar rats were used for this study and were randomly distributed into six groups (n=7). Rats in group 1 were used as control and were administered normal saline; group 2 rats were healthy rats administered 50 mg/kg of kola nut extract per day; group 3 rats were healthy rats administered 100 mg/kg of kola nut extract per day; group 4 rats were a diabetic group also administered normal saline; group 5 rats were diabetic rats administered 50 mg/kg of kola nut extract per day; and group 6 rats were diabetic rats administered 100 mg/kg of kola nut extract per day. Diabetes was induced with 50 mg/kg of STZ. After 3 weeks of administration, the spatial memories of the rats were tested using the Y-maze, followed by assay of Na+/K+-ATPase activity. Results The result shows a significant increase in Na+/K+-ATPase activity of diabetic treated groups (5 and 6) when compared with the diabetic group (4) and a significant increase in Na+/K+-ATPase activity of healthy treated groups (2 and 3) when compared with control. Also, there was a significant increase in spatial memory of the diabetic treated groups when compared with diabetic group. Conclusions This study revealed that kola nut extract has restorative effect on brain Na+/K+-ATPase activities and spatial memory of STZ-induced diabetic female Wistar rats.

Anti-inflammatory and bronchodilatory constituents of leaf extracts of Anacardium occidentale L. in animal models

OBJECTIVE

Anacardium occidentale L. leaf is useful in the treatment of inflammation and asthma, but the bioactive constituents responsible for these activities have not been characterized. Therefore, this study was aimed at identifying the bioactive constituent(s) of A. occidentale ethanolic leaf extract (AOEL) and its solvent-soluble portions, and evaluating their effects on histamine-induced paw edema and bronchoconstriction.

METHODS

The bronchodilatory effect was determined by measuring the percentage protection provided by plant extracts in the histamine-induced bronchoconstriction model in guinea pigs. The anti-inflammatory effect of the extracts on histamine-induced paw edema in rats was determined by measuring the increase in paw diameter, after which the percent edema inhibition was calculated. The extracts were analyzed using gas chromatography-mass spectrometry to identify the bioactive constituents. Column chromatography and Fourier transform infrared spectroscopy were used respectively to isolate and characterize the constituents. The bronchodilatory and anti-inflammatory activities of the isolated bioactive constituent were evaluated.

RESULTS

Histamine induced bronchoconstriction in the guinea pigs and edema in the rat paw. AOEL, hexane-soluble portion of AOEL, ethyl acetate-soluble portion of AOEL, and chloroform-soluble portion of AOEL significantly increased bronchodilatory and anti-inflammatory activities (P < 0.05). Oleamide (9-octadecenamide) was identified as the most abundant compound in the extracts and was isolated. Oleamide significantly increased bronchodilatory and anti-inflammatory activities by 32.97% and 98.41%, respectively (P < 0.05).

CONCLUSION

These results indicate that oleamide is one of the bioactive constituents responsible for the bronchodilatory and anti-inflammatory activity of A. occidentale leaf, and can therefore be employed in the management of bronchoconstriction and inflammation.

Resting Serum Concentration of High-Sensitivity C-Reactive Protein (hs-CRP) in Sportsmen and Untrained Male Adults

There is an inverse relationship between regular physical activity and concentration of serum inflammatory markers, with variations in resting CRP in trained and untrained subjects. The effect of acute and prolonged exercises has been studied on inflammatory markers with dearth of information and controversies on the resting serum values of high sensitivity CRP (hs-CRP). Therefore, this study sought to identify and compare variations that occur in serum levels of high sensitivity CRP in groups of sportsmen (6) and physically active untrained subjects. Eighty-one healthy male participants made up of 21 untrained (control), 10 footballers, 10 athletes, 10 karates, 10 volleyballers, 10 basketballers, and 10 baseballers voluntarily participated in the study. Participants rested while in sitting position for about 30 minutes during which blood pressures and heart rates were taken. 5 mls of venous blood was withdrawn from the antecubital vein of the participants (aseptically) between 7:00 and 10:00 am into lithium heparin bottles following an overnight fast. The supernatant was decanted and centrifuged at 3000 rpm, serum was collected and stored at -20ºC prior to biochemical assay which was done with the use of enzyme linked immunosorbent assay (ELISA) kits for hs-CRP. Differences in the means within the sporting groups were analysed using one-way ANOVA while the difference between the trained sportsmen and untrained young adults was analysed using the independent T-test. Statistical significance was set at p < 0.05. The Mean ±SEM age, weight, height, and BMI of the participants were 22.0±0.8 years, 64.1±2.2 kg, 1.74±0.3 m, and 20.6±0.2 kg/m2 respectively. The resting concentration of hs-CRP (µg/ml) was 1.0±0.2 in the untrained, 2.6±0.7 in footballers, 3.6±2.1 in track athletes, 2.4±0.5 in basketballers, 2.2±0.5 in volleyballers, 2.4±1.3 in baseballers, and 1.7±0.5 in karate respectively. There was no significant difference in the resting hs-CRP amongst the sporting groups, and in the sportsmen and untrained group. Resting serum levels of hs-CRP falls within normal range, and varies insignificantly in groups of sports, and in sportsmen and untrained young male adults. This may suggest that the types of sporting activities or participation in sports has no impact on the resting serum hs-CRP.

Honey prevents neurobehavioural deficit and oxidative stress induced by lead acetate exposure in male Wistar rats- a preliminary study

This research sought to investigate the possible neuroprotective effects of honey against lead (Pb)-induced neurotoxicity. Twenty four male Wistar rats were divided into four groups: Control group that received 1 ml/kg distilled orally for 28 days; while groups II-IV received 0.2% lead in drinking water and 1 ml/kg of distilled water, 1 ml/kg of honey, 1.5 ml/kg of honey respectively for 28 days. Anxiety and exploratory activities were determined in the open field test. Memory function was determined using Morris water maze after which the animals were sacrificed. The brains were then excised, homogenized and Lipid peroxidation (MDA), Superoxide dismutase (SOD), Catalase, Glutathione (GSH) and Glutathione -S- Transferase (GST) activities were determined in the brains. Results showed that lead exposure causes decrease in locomotor and exploratory activities; increase anxiety, memory impairment, lipid peroxidation and decrease antioxidant activities. However, co-administration of honey with lead inhibited neurotoxicity as indicated by the improvement in memory function as evidenced by decreased latency period and increased in time spent in target quadrant in honey-fed rats compared to the lead-exposed animals. Furthermore, honey increased locomotion, exploration and decreased anxiety in lead-exposed rats as indicated by the frequency of rearing, freezing duration and the number of line crossed by animals. Also administration of honey improves antioxidant activities as shown by increased brain SOD, GST and GSH activities compared to the lead-treated groups but no significant effect on MDA level. It can be concluded that honey has neuroprotective effects against lead-induced cognitive deficit probably by enhancing antioxidant activities.

Effect of taurine and caffeine on plasma c-reactive protein and calcium in Wistar rats

BACKGROUND

Caffeine is a component of several beverages such as coffee and tea. It has been shown to possess psychoactive properties because it increases alertness, energy and ability to concentrate at moderate doses. Taurine on the other hand, is an amino acid which has the capacity to promote neural development, osmoregulation and neuroprotection. There is paucity of information on the effect of the combined administration of taurine and caffeine on C-reactive protein (CRP)--a marker of inflammation and plasma calcium level in rats.

AIM

The present study was designed to investigate the effects of combined taurine and caffeine on the plasma level of CRP, Ca2+ as well as the effect of nifedipine on calcium level.

METHOD

Fifty four rats weighing 120-140 g were used for these studies. The animals were divided into nine groups consisting of six animals each. Group 1 was treated with 10 m/kg of normal saline, Groups 2 and 3 were given 100 mg/kg and 200 mg/kg of taurine respectively, groups 4 and 5 received 7.5 mg/kg and 15 mg/kg of caffeine respectively while group 6 was administered taurine (200 mg/kg) and caffeine (15 mg/kg), groups 7 and 8 were treated with taurine (200 mg/kg) plus nifedipine (10 mg/kg) and taurine (200 mg/kg)plus furosemide (20 mg/kg) respectively while group 9 was given taurine plu caffeine plus nifdipine plus furosemide. Treatment was done once daily for 21 days and blood was finally collected via cardiac puncture for the assay of CRP and calcium while the animals were under anaesthesia.

RESULTS

The results showed that CRP was significantly decreased in five of the treated groups compared with the control with the exception of the group treated with taurine alone (Group 2), and that treated with combined taurine and caffeine (Group 6). The Ca2+ level of groups treated with caffeine (11.70 ± 0.29 mg/dL) and taurine with caffeine (11.64 ± 0.15 mg/dL) were significantly (p < 0.05) increased compared with the control (10.70 ± 0.29 mg/dL). However, treatment with taurine and nifedipine (Group 7) led to significant (p < 0.05) reduction in plasma Ca2+ level.

CONCLUSION

The results have shown that combined caffeine and taurine can boost plasma calcium level and decrease plasma CRP level. Moreover, taurine combined with nifedipine but not furosemide can act synergistically to lower both plasma Ca2+ and CRP levels, a result which may have implication for the treatment of hypertension.

Analgesic and anti-inflammatory effects of honey: the involvement of autonomic receptors

The use of honey for therapeutic purposes is on the increase and many studies have shown that honey has the ability to influence biological systems including pain transmission. Therefore, this study was designed to investigate the analgesic and anti-inflammatory effects of honey and the effects of concurrent administration of autonomic nervous system blocking drugs. Studies on analgesic activities was carried out using hotplate and formalin-induced paw licking models while the anti-inflammatory activity was by the carrageenan paw oedema method. Animals were distributed into six groups consisting of five animals each. They were administered saline, honey (600 mg/kg), indomethacin (5 mg/kg), autonomic blockers (3 μg/kg of tamsulosin, 20 mg/kg (intraperitoneally) of propranolol, 2 ml/kg of atropine or 10 mg/kg (intra muscularly) of hexamethonium) or honey (200 and 600 mg/kg) with one of the blockers. The results showed that honey reduced pain perception especially inflammatory pain and the administration of tamsulosin and propranolol spared the effect of honey. Hexamethonium also spared the effects of honey at the early and late phases of the test while atropine only inhibited the early phase of the test. However, atropine and hexamethonium spared the anti-inflammatory effects of honey but tamsulosin abolished the effects while propranolol only abolished the anti-inflammatory effects at the peak of the inflammation. The results suggest the involvement of autonomic receptors in the anti-nociceptive and anti-inflammatory effects of honey although the level of involvement depends on the different types of the receptors.

Haemtological Parameters of Residents of Offa, KWARA State

Objectives: This study aims to study some hematologic parameters, here, the packed cell volume (PCV), the red blood cell (RBC) count, hemoglobin concentration (HC) and white blood cell (WBC) count in residents of Offa in Kwara state, Nigeria. Methods: Blood samples of healthy male and female Offa indigenes were analyzed for RBC count, PCV, HC and WBC count. Results: The mean HC was 14.6 and 13.71 g/dl of blood, for both males and females respectively, while the mean PCV was 43.1% and 40.4% for both males and females, respectively. The mean RBC count for males was 5.45 x 166 cells per mm3 while that of females was 4.55 x 106 / mm3. Conclusion: All values investigated were lower than that for Caucasians. The probable causes of the differences between the above values as compared to those of the western world were also discussed. Bangladesh Journal of Medical Science Vol. 12 No. 02 April’13 Page 180-185 DOI: http://dx.doi.org/10.3329/bjms.v12i2.14947

Effects of honey on inflammation and nitric oxide production in Wistar rats

OBJECTIVE

The aim of the study is to investigate the effects of honey on acute and chronic inflammations and nitric oxide production in rats.

METHODS

Carrageenan, cotton pellet and formaldehyde methods were used in quantifying the anti-inflammatory effect of honey while the effect of honey on nitric oxide (NO) production was investigated by administering NG-nitro-L-arginine methyl ester (L-NAME, 100 mg/kg body weight, subcutaneously) and L-arginine (300 mg/kg body weight, intraperitoneally) to groups of rats. Animals were divided into five groups each comprising of five rats in each experiment; two groups were orally administered distilled water (control) and indomethacin (5 mg/kg body weight), respectively, while the remaining three groups were administered 2, 6 and 10 g/kg honey for anti-inflammatory studies.

RESULTS

Honey significantly (P<0.05) reduced the paw size in the carrageenan model, while in the cotton pellet model, the granuloma weight was significantly (P<0.05) reduced. Honey also significantly (P<0.05) reduced the arthritis induced by formaldehyde injection from the second day of the study. In the investigation on NO involvement, L-NAME significantly inhibited paw oedema while the administration of L-arginine abolished the anti-inflammatory effect of honey and L-NAME.

CONCLUSION

The results obtained from the study confirm that honey has an anti-inflammatory effect which may be due in part to inhibition of NO release. Therefore honey may be used to treat certain acute and chronic inflammatory conditions.

Anti-nociceptive and anti-inflammatory properties of the ethanolic extract of Lagenaria breviflora whole fruit in rat and mice

The present study was conducted to evaluate the anti-nociceptive and anti-inflammatory properties of an ethanol extract of whole fruit of Lagenaria breviflora (LB) in rat and mice. Analgesic activity was measured by hot plate, formalin-induced paw licking, and acetic acid-induced abdominal writhing tests, while anti-inflammatory activity was determined by inhibition of carrageenan-induced paw oedema. Extract-treated animals exhibited significantly (P<0.05) higher pain threshold, lower number of licking of paws in response to formalin-induced irritation and writhing movements in response to acetic acid-induced writhing movement. There was significant (P<0.05) inhibition of carrageenan-induced paw oedema in rats pre-treated with the extract (50, 100, 200mg/kg) by 6.4%, 27.5%, 55.9% respectively. Analgesic effect of the extract (50, 100, 200mg/kg) in hot plate test was observable within 30 minutes of administration with maximum effect obtainable 90 minutes post-administration. Also, the effect of the extract (50, 100 and 200mg/kg) was dose dependent in both the early (88.17±6.21, 80.33±3.49 and 72.33±5.16) and late (72.50±3.95, 53.83±3.96 and 35.83±3.78) phases of formalin-induced paw licking, and in acetic acid-induced writhing with inhibition of 26.8%, 48.1% and 58.1% respectively. Its effect was comparable especially at 200mg/kg body weight to those of diclofenac, indomethacin and ibuprofen. It could be suggested from the findings of this experiment that the extract may be mediating its action as a central analgesic agent but the peripheral analgesic effect was preponderant based on its outcome from the pain models.

Analgesic, anti-inflammatory and antipyretic effects of the ethanol extract of Acalypha wilkesiana leaves in rats

The leaves of Acalypha wilkesiana are commonly used for the treatment of pain, fever and ulcer by traditional medical practitioners without any scientific data to evaluate the appropriateness of some of the practices. Therefore, this study was carried out to determine whether the ethanol extract of Acalypha wilkesiana has analgesic, anti-inflammatory and antipyretic as well as anti-ulcer effects. The hot plate latency assay and formalin- induced paw licking models were used to evaluate analgesic effects. Animals were divided into groups comprising of five rats each. There were control (administered saline) and reference (administered indomethacin) groups. Also there were three extract groups administered 25, 50 or 100 mg/Kg body weight of extracts. Ulcer was induced using absolute ethanol followed by pylorus ligation in all animals; inflammation was induced using carrageenan while pyrexia was induced by injecting brewer's yeast intramuscularly into the dorsal part of the abdominal cavities of the rats. Different sets of rats were used for the anti-ulcer, anti-inflammatory and antipyretic studies although animal grouping for extract administration were as in analgesic studies. The results show that the extract produced dose-dependent and significant (p<0.05) analgesic and anti-inflammatory activities. The extract also significantly protected against ethanol induced ulcer. Likewise, the extract significantly (p<0.05) reduced the pyretic states of the animals. This study has therefore further provides evidences that may support the ethnomedicinal uses of the ethanolic extracts of Acalypha wilkesiana leaves.

Haematological evaluation of ethanolic extract of Allium ascalonicum in male albino rats

The haematological effect of ethanolic extract of Allium ascalonicum was evaluated in male albino rats during a 21 day administration at the doses of 50, 100 and 200 mg/kg b.w, orally. Parameters evaluated include the serum lipids, red and white cell indices. The results showed that the extract administered decreased most of the parameters relating to red cell and increased most of those parameters relating to white cells. It also decreased the total cholesterol (TCH), high density lipoprotein cholesterol (HDL) and low density lipoprotein cholesterol (LDL) with no significant effect on the triglyceride levels.