Melatonin and Vitamin C modulate cholinergic neurotransmission and oxidative stress in scopolamine-induced rat model of memory impairment

Background: Cognitive dysfunction which characterizes dementia is reportedly caused by multiple factors including oxidant-antioxidant imbalance, inflammation, alteration in synaptic neurotransmission. Despite the arrays of drugs available in managing dementia, it appears no single drug can effectively treat dementia. Since it is multifactorial, combining potential drugs may provide neuroprotective impact. As such, this study investigated the neuroprotective effects of melatonin and vitamin C on scopolamine model of cognitive impairment in rats and the possible mechanism of action. Methods: Thirty male Wistar rats were divided to receive either normal saline (5 ml/kg, p.o), scopolamine (1 mg/kg, i.p.), donepezil (2 mg/kg, p.o), melatonin (10 mg/kg, p.o), vitamin C (100 mg/kg. p.o) or melatonin plus vitamin C. Cognitive impairment was induced by daily injection of scopolamine (1 mg/kg, i.p.), after which different treatment regimen were administered for 15 days. Spatial memory was assessed using Morris Water Maze and modified light and dark box. The brain was processed for malondialdehyde (MDA), reduced glutathione (GSH) and acetylcholinesterase (AchE) activity. Results: Scopolamine-treated rats with no intervention showed impaired learning and memory as depicted by a significant (p<0.05) increase in escape latency, reduction in the frequency of visit to the escape aperture, increased MDA, decreased GSH and elevated acetylcholinesterase activity when compared to other groups. Interventions with melatonin or/and vitamin C reversed these responses respectively. The melatonin plus vitamin C treated group compared favorably with donepezil (reference group). Conclusion: Melatonin and vitamin C show neuroprotective effect in attenuating cognitive impairment in scopolamine-induced model by modulating oxidative stress pathway and enhancing cholinergic neurotransmission. Keywords: Dementia, Melatonin, Vitamin C, Memory, Scopolamine

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.Keywords: Resting hs-CRP, Sportsmen, Young male adult

Knee osteoarthritis increases pain perception and alters interleukins (6 and 10) levels in patients in South-West, Nigeria

Background: Osteoarthritis is a chronic degenerative joint disease which can affect any joint in the body, usually accompanied by pain. The onset and progression of the disease is determined by several factors such as genetic, gender, occupation and ethnicity. There is paucity of information on pain perception and biochemical profile in Osteoarthritis of the knee (KOA) patients in Nigeria.Objective: To assess the pain perception and some biomarkers in osteoarthritic patients in South-west, Nigeria.Design: A retrospective studySetting: Nationally representing South-West region of NigeriaSubjects: A total of sixty human adult subjects were used in this study (Control group, 30 healthy and KOA group, 30 diagnosed with OA) Main outcome measures: All the subjects underwent the Ischemia-induced pain test and blood samples were taken from them for the determination of serum interleukin-6 (IL-6), interleukin-10 (IL-10) and calcitonin gene related peptide (CGRP).Results: The results showed a significantly (p<0.05) higher pain threshold and pain tolerance in healthy individuals compared to KOA patients. There was also a significantly (p<0.05) elevated level of IL-6 in the serum of KOA patients compared to control (13.0 ± 0.7 vs 20.1±3.2 pg/dl) and a significantly (p<0.05) lower level of IL-10 in the serum of OA patients compared to control (14.3± 3.1 vs 4.1 ±0.5 pg/dl).Conclusion: There was no difference in the serum level of CGRP in the control compared with the KOA group. In conclusion, KOA causes decrease in pain tolerance and threshold which is accompanied by alteration in vital biochemical parameters

ANTI - INFLAMMATORY AND ANALGESIC ACTIVITIES OF NOTHOSPONDIAS STAUDTII

The aqueous (AENS), methanolic (MENS) and chloroform (CENS) extracts of the leaves of Nothospondias staudtii Engl (Anacardianceae) were screened for analgesic and anti-inflammatory activities in mice and rats. Pain responses were studied in mice using the tail immersion and acetic acid induced writing while carrageenan induced paw oedema was used to access anti-inflammatory activity. The three extracts exhibited significant analgesic compared with the control (saline, 10ml/kg) as evidenced by (i) increased escape latency in the tail immersion assay (ii) reduction in abdominal writhing induced by acetic acid. The analgesic activity were higher in MENS & CENS compared to aspirin (150mg/kg). The extracts progressively reduced rat paw oedema induced by subplantar injection of carrageenan, the methanolic extract showing more pronounced effect than the aqueous and chloroform extracts. Preliminary phyto-chemical screening shows the presence of alkaloids, sugars, proteins and anti-oxidants in the extract

Effects of Caffeine Administration on Body Weight and Memory in Healthy and Streptozotocine-Induced Diabetic Female Wistar Rats

Diabetes is a metabolic condition characterized by inability of the individual to regulate blood glucose within reference levels due to insufficient insulin or ineffective insulin sensitivity by the tissue. There have been reports and observations on the effect of type I diabetes on body weight and cognitive function especially during treatment. We therefore aim to determine the effects of caffeine on body weight and memory in Streptozotocine-Induced diabetic female Wistar rats.Eight groups of female Wistar rats with mean weight of 180g were used for the study. Groups 1 and 2 were control and diabetic respectively, administered 20mg/kg of normal saline intraperitoneally. Groups 3, 4 and 5 were administered 15, 20 and 25 mg/kg of caffeine intraperitoneally (i/p) per day respectively for five weeks and maintained on caffeine for three weeks after induction of diabetes; groups 6, 7 and 8 were diabetic rats administered caffeine at 15, 20, and 25 mg/kg (i/p) respectively per day for three weeks. Diabetes was induced with 50 mg/kg STZ. Body weight and blood glucose level were monitored weekly. At the end of administration, Morris Water Maze was used to measure their spatial learning and memory. Animals were euthanized by cardiac puncture.There was no significant (p<0.05) difference in percentage weight change in healthy groups 3, 4, 5 when compared to control. There was significant (p<0.05) decrease in percent weight change in groups 4, 5, 6 and 7 when compared to control.There was significant (p<0.05) decrease in duration to locate the hidden platform of Morris water maze in groups 3 and 5 when compared to control and diabetic group.In conclusion, this study shows that caffeine has no effect on body weight in healthy rats but has a dose and time dependent effect on body weight as well as a preventive effect on cognitive decline in diabetic rats.Keywords: Caffeine, Diabetes, Body weight, Learning, Memory

Secondary Metabolites Constituents and Antibacterial Screening of Methanolic Leaves Extracts of Senna fistula and Ocimum gratissimum

The misuse of antibiotics has contributed largely to the development of resistance strains thereby creating the need for an incessant search and development of newer drugs. This study investigated the secondary metabolites constituents and antibacterial activity of methanolic leaves extracts of Senna fistula (SF) and Ocimum gratissimum (OG). The SF and OG leaves extracts were done using methanol, the phytochemical analysis were done as per standard protocol. The antibacterial activity was determined by agar well diffusion method.The results showed that the methanolic leaves extracts of SF and OG contain secondary metabolites like flavonoids, tannins, alkaloids, terpenoids, cardiac gylcosides, saponins, phenolic compounds. The antibacterial screening revealed that both Senna fistula and Ocimum gratissimum exhibited strong inhibitory activity against all the tested organisms. Methanolic leaf extract of SF has a stronger antibacterial activity with zones of inhibition of 19.5mm against E coli  and 31.5 mm against Klebsiella than methanolic leaf extract of OG (18 mm against E coli and 28 mm against Klebsiella) in a dose dependent manner.In conclusion, the methanolic leaves extracts of Senna fistula and Ocimum gratissimum exhibited antibacterial activity which is due to the presence of various secondary metabolites; therefore this study supports its use as an antibiotic agent.Keywords: Senna fistula, Antibacterial, Terpenoids, Klebsiella, Ocimum gratissimum, Secondary metabolite

Anti-inflammatory and analgesic activities of leaf extracts of Landolphia Owariensis

The aqueous, methanol and chloroform extracts of Landolphia owariensis leaves (AELO, MELO & CELO respectively) was investigated for anti-inflammatory and analgesic activities. All the extracts (100mg/kg each) were found to significantly (P<0.05) inhibit paw edema induced by carrageenan in rats and the nociception induced by Tail immersion in hot water (50.0 ± 1.0°C) and acetic acid. The methanol extract produced the highest paw edema inhibition while in thermally induced nociception both the MELO and CELO show high and comparable analgesic activity with acetylsalicylic acid (150mg/kg). However in chemically induced pain (acetic acid) MELO produced the highest and comparable analgesic activity to acetylsalicylic acid (150mg/kg). We therefore conclude, that apart from the folklore uses of L. Owariensis leaves as antimalarial agents, the various extracts of the plant also possess anti-inflammatory and analgesic activities. Phytochemical analysis showed that the methanollic extract of L. owerensis contain some secondary metabolites namely: alkaloids and some polyphenolic compounds. Also, this extract exhibits some anti-oxidative activities

Rapid eye movement sleep deprivation impairs hippocampus-dependent spatial memory: involvement of GABAergic receptors

Background: This study examined the effect of rapid eye movement (REM) sleep deprivation on spatial memory in Wistar rats and the role of GABAergic receptors.Methods: A total of thirty-six age matched male Wistar rats weighing 170-200g were grouped into six (A-F) of six animals each. Group A served as control, Group B was sleep deprived, rats in groups C-F in addition to being sleep deprived for 72 hrs, received Diazepam (1mg/kg) (C), Baclofen (5mg/kg) (D), Phaclofen (1mg/kg) (E), Bicuculline (2mg/kg) (F) respectively. Spatial memory was accessed using Morris water maize (MWM) while motor performance (MP) and working memory were accessed using Y-Maze. Some serum biochemical parameters were also assessed.Results: These showed that spatial memory was decreased in the sleep deprived group compared with control (p&lt;0.05). Diazepam increased, while Bicuculline decreased time latency in the MWM compared with sleep-deprived group (p&lt;0.05). MP in the Y maze was significantly reduced (p&lt;0.05) in all groups compared with control. Serum Creatine kinase (CK) and calcium as well as hippocampal CK were significantly (p&lt;0.05) increased in the sleep-deprived group compared with control.Conclusion: REM sleep deprivation produced impairment in spatial memory in rats which is at least in part mediated by Gabaergic mechanisms with GABA A receptors being more implicated than the B subtype.Keywords: Rapid eye movement sleep, sleep deprivation, spatial memory, GABA receptor

Honey Prevents Lead Induced Renal Dysfunction By Improving Antioxidant Activities in Male Wistar Rats

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Histomorphological evaluation of wound healing - Comparison between use of honey and Vernonia amygdalina leaf juice

Vernonia amygdalina Del. crude sap has been used for wound management in ethnomedicine. Histological evaluation of Vernonia amygdalina leaf juice effect on wound healing was carried out. Female albino rats (150-200 g) were anaesthetized, shaved and induced a circular excision wound (10 mm diameter) at the dorso-lateral region. They were randomly assigned (n = 5) to honey, Vernonia amygdalina leaf juice and deionised water (negative control; NC) treated groups (topically treated twice/day with 20 µL each of the respective treatments). Wound size was measured using a digital camera (Canon Powershot 5.0MP, Canon, Tokyo, Japan) and Adobe photoshop CS5 software. Wound tissues were removed on days 3, 5, 7 and 10 post wounding for histomorphological examinations. Average time for complete wound closure in honey (11.00 ± 0.00 days) and Vernonia amygdalina leaf juice (11.20 ± 0.44 days) treated groups was significantly (p˂ 0.05) shorter when compared to NC (13.4 ± 0.90 days). Vernonia amygdalina leaf juice, similar to honey, enhanced fibroblasts recruitment, epithelia cells migration, neovascularization and reduced polymorphonuclear leukocytes (PMNL) infiltration as compared to the NC at the early phase of wound healing (days 3 and 5). Vernonia amygdalina might enhance cutaneous wound healing through mechanisms associated with activation/differentiation of skin cells and inhibition of PMNL infiltration of wound area.Keywords: Histology, Vernonia amygdalina, Honey, Wound healin