Mustapha Muzaimi

From Kratom to mitragynine and its derivatives: Physiological and behavioural effects related to use, abuse, and addiction

Kratom (or Ketum) is a psychoactive plant preparation used in Southeast Asia. It is derived from the plant Mitragyna speciosa Korth. Kratom as well as its main alkaloid, mitragynine, currently spreads around the world. Thus, addiction potential and adverse health consequences are becoming an important issue for health authorities. Here we reviewed the available evidence and identified future research needs. It was found that mitragynine and M. speciosa preparations are systematically consumed with rather well defined instrumentalization goals, e.g. to enhance tolerance for hard work or as a substitute in the self-treatment of opiate addiction. There is also evidence from experimental animal models supporting analgesic, muscle relaxant, anti-inflammatory as well as strong anorectic effects. In humans, regular consumption may escalate, lead to tolerance and may yield aversive withdrawal effects. Mitragynine and its derivatives actions in the central nervous system involve μ-opioid receptors, neuronal Ca²⁺ channels and descending monoaminergic projections. Altogether, available data currently suggest both, a therapeutic as well as an abuse potential.

Population based study of late onset cerebellar ataxia in south east Wales

Objective: To determine the prevalence and causation of late onset cerebellar ataxia (LOCA) in south east Wales, United Kingdom. Methods: A population based study of LOCA was conducted in a defined geographical region with a total population of 742 400. Multiple sources of ascertainment were used to identify all cases prevalent on 1 January 2001. The inclusion criteria were: a predominantly progressive cerebellar ataxia with onset of symptoms at age ⩾18 years; and disease duration of ⩾1 year. Cases with known acquired ataxias, ataxic syndromes with associated prominent autonomic dysfunction and/or atypical parkinsonism suggestive of multiple system atrophy and disorders with ataxia as a minor feature were excluded. Results: We identified 76 index cases of LOCA, of whom 63 were sporadic, idiopathic LOCA (ILOCA) and 13 were familial LOCA, of whom six had either spinocerebellar ataxia type 6, Friedreich’s ataxia or dominant episodic ataxia. The mean annual incidence rate for the period 1999–2001 was 0.3/100 000 population/year. The crude prevalence rates were 8.4 per 100 000 (95% CI 7.2 to 11.6) for ILOCA and 1.8 per 100 000 (95% CI 0.8 to 2.7) for inherited LOCA. Of the 54/63 (85.7%) patients with ILOCA who were assessed, mean (SD) age at onset of symptoms was 53.8 (14.1) years (range 19 to 78) with a male:female ratio of 2.1:1. The mean disease duration was 8.7 (6.3) years (range 1 to 31). The most frequent presenting complaint was disturbance in gait (90.7%). One-third had a relatively pure cerebellar syndrome (33.3%) and two-thirds (66.7%) had additional extracerebellar neurological features. The majority (92%) were ambulant but only 9.3% were independently self-caring. Conclusion: This population based study provides insight into LOCA within a defined region and will inform decisions about the rational use of healthcare resources for patients with LOCA.

Task specific focal dystonia: a presentation of spinocerebellar ataxia type 6

Autosomal dominant cerebellar ataxias (ADCA) are characterised by clinical and genetic heterogeneity with a substantial overlap of clinical features and a variable degree of adherence to three distinct phenotypes according to Harding’s clinical classification: ADCA type I, II, and III.1 The availability of molecular genetic testing has provided increasing appreciation of a wider clinical spectrum than previously thought for each ADCA subgroup. In addition there is an increasing list of genes harbouring disease causing mutations which, to date, include spinocerebellar ataxia (SCA) types 1, 2, 3, 6, 7, 8, 10, 12, and 17.2 SCA 6 is caused by unstable CAG expansion in the α-1A calcium channel gene (CACNA1A).4 We present a confirmed case of SCA 6 presenting with a task specific focal dystonia (writer’s cramp) predated the onset of progressive gait ataxia by five years, which further widens the clinical spectrum of SCA 6. A 57 year old female pharmacist first presented at the age of 42 with a two month history of progressive difficulty in writing prescriptions as a result of writing induced cramp affecting the right hand. This task specific focal dystonia was aggravated by stress and fatigue. Her father was reported to have had Parkinson’s disease on the basis of developing tremor and gait disturbance at age 40. On examination, the patient’s gait was normal and no focal neurological deficits were …

Time course of motor and cognitive functions after chronic cerebral ischemia in rats.

Cerebral ischemia is one of the leading causes of death and long-term disability in aging populations, due to the frequent occurrence of irreversible brain damage and subsequent loss of neuronal function which lead to cognitive impairment and some motor dysfunction. In the present study, the real time course of motor and cognitive functions were evaluated following the chronic cerebral ischemia induced by permanent, bilateral occlusion of the common carotid arteries (PBOCCA). Male Sprague Dawley rats (200-300g) were subjected to PBOCCA or sham-operated surgery and tested 1, 2, 3 and 4 weeks following the ischemic insult. The results showed that PBOCCA significantly reduced step-through latency in a passive avoidance task at all time points when compared to the sham-operated group. PBOCCA rats also showed significant increase in escape latencies during training in the Morris water maze, as well as a reduction of the percentage of times spend in target quadrant of the maze at all time points following the occlusion. Importantly, there were no significant changes in locomotor activity between PBOCCA and sham-operated groups. The BDNF expression in the hippocampus was 29.3±3.1% and 40.1±2.6% on day 14 and 28 post PBOCCA, respectively compared to sham-operated group. Present data suggest that the PBOCCA procedure effectively induces behavioral, cognitive symptoms associated with cerebral ischemia and, consequently, provides a valuable model to study ischemia and related neurodegenerative disorder such as Alzheimers disease and vascular dementia.

Better Glasgow outcome score, cerebral perfusion pressure and focal brain oxygenation in severely traumatized brain following direct regional brain hypothermia therapy: A prospective randomized study.

Background: Induced hypothermia for treatment of traumatic brain injury is controversial. Since many pathways involved in the pathophysiology of secondary brain injury are temperature dependent, regional brain hypothermia is thought capable to mitigate those processes. The objectives of this study are to assess the therapeutic effects and complications of regional brain cooling in severe head injury with Glasgow coma scale (GCS) 6-7. Materials and Methods: A prospective randomized controlled pilot study involving patients with severe traumatic brain injury with GCS 6 and 7 who required decompressive craniectomy. Patients were randomized into two groups: Cooling and no cooling. For the cooling group, analysis was made by dividing the group into mild and deep cooling. Brain was cooled by irrigating the brain continuously with cold Hartmann solution for 24-48 h. Main outcome assessments were a dichotomized Glasgow outcome score (GOS) at 6 months posttrauma. Results: A total of 32 patients were recruited. The cooling-treated patients did better than no cooling. There were 63.2% of patients in cooling group attained good GOS at 6 months compared to only 15.4% in noncooling group (P = 0.007). Interestingly, the analysis at 6 months post-trauma disclosed mild-cooling-treated patients did better than no cooling (70% vs. 15.4% attained good GOS, P = 0.013) and apparently, the deep-cooling-treated patients failed to be better than either no cooling (P = 0.074) or mild cooling group (P = 0.650). Conclusion: Data from this pilot study imply direct regional brain hypothermia appears safe, feasible and maybe beneficial in treating severely head-injured patients.

Chronic mitragynine (kratom) enhances punishment resistance in natural reward seeking and impairs place learning in mice

Kratom (Mitragyna speciosa) is a widely abused herbal drug preparation in Southeast Asia. It is often consumed as a substitute for heroin, but imposing itself unknown harms and addictive burdens. Mitragynine is the major psychostimulant constituent of kratom that has recently been reported to induce morphine‐like behavioural and cognitive effects in rodents. The effects of chronic consumption on non‐drug related behaviours are still unclear. In the present study, we investigated the effects of chronic mitragynine treatment on spontaneous activity, reward‐related behaviour and cognition in mice in an IntelliCage® system, and compared them with those of morphine and Δ‐9‐tetrahydrocannabinol (THC). We found that chronic mitragynine treatment significantly potentiated horizontal exploratory activity. It enhanced spontaneous sucrose preference and also its persistence when the preference had aversive consequences. Furthermore, mitragynine impaired place learning and its reversal. Thereby, mitragynine effects closely resembled that of morphine and THC sensitisation. These findings suggest that chronic mitragynine exposure enhances spontaneous locomotor activity and the preference for natural rewards, but impairs learning and memory. These findings confirm pleiotropic effects of mitragynine (kratom) on human lifestyle, but may also support the recognition of the drugs harm potential.

Kainic Acid-Induced Excitotoxicity Experimental Model: Protective Merits of Natural Products and Plant Extracts

Excitotoxicity is well recognized as a major pathological process of neuronal death in neurodegenerative diseases involving the central nervous system (CNS). In the animal models of neurodegeneration, excitotoxicity is commonly induced experimentally by chemical convulsants, particularly kainic acid (KA). KA-induced excitotoxicity in rodent models has been shown to result in seizures, behavioral changes, oxidative stress, glial activation, inflammatory mediator production, endoplasmic reticulum stress, mitochondrial dysfunction, and selective neurodegeneration in the brain upon KA administration. Recently, there is an emerging trend to search for natural sources to combat against excitotoxicity-associated neurodegenerative diseases. Natural products and plant extracts had attracted a considerable amount of attention because of their reported beneficial effects on the CNS, particularly their neuroprotective effect against excitotoxicity. They provide significant reduction and/or protection against the development and progression of acute and chronic neurodegeneration. This indicates that natural products and plants extracts may be useful in protecting against excitotoxicity-associated neurodegeneration. Thus, targeting of multiple pathways simultaneously may be the strategy to maximize the neuroprotection effect. This review summarizes the mechanisms involved in KA-induced excitotoxicity and attempts to collate the various researches related to the protective effect of natural products and plant extracts in the KA model of neurodegeneration.

Effect of tualang honey against KA-induced oxidative stress and neurodegeneration in the cortex of rats.

BackgroundAdministration of KA on rodents has resulted in seizures, behavioral changes, oxidative stress, and neuronal degeneration on selective population of neurons in the brain. The present study was undertaken to investigate the extent of neuroprotective effect conferred by Malaysian Tualang Honey (TH), an antioxidant agent, in the cerebral cortex of rats against KA-induced oxidative stress and neurodegeneration in an animal model of KA-induced excitotoxicity.MethodsMale Sprague–Dawley rats were randomly divided into five groups: Control, KA-treated group, TH + KA-treated group, aspirin (ASP; anti-inflammatory agent) + KA-treated group and topiramate (TPM; antiepileptic agent) + KA-treated group. The animals were pretreated orally with drinking water, TH (1.0g/kg BW), ASP (7.5mg/kg BW) or TPM (40mg/kg BW), respectively, five times at 12 h intervals. KA (15mg/kg BW) was injected subcutaneously 30 min after last treatment to all groups except the control group (normal saline). Behavioral change was observed using an open field test (OFT) to assess the locomotor activity of the animals. Animals were sacrificed after 2 h, 24 h and 48 h of KA administration.ResultsKA significantly inflicted more neuronal degeneration in the piriform cortex and heightened the predilection to seizures as compared with the control animals. Pretreatment with TH reduced the KA-induced neuronal degeneration in the piriform cortex but failed to prevent the occurrence of KA-induced seizures. In the OFT, KA-induced animals showed an increased in locomotor activity and hyperactivity and these were attenuated by TH pretreatment. Furthermore, TH pretreatment significantly attenuated an increase of thiobarbituric acid reactive substances level and a decrease of total antioxidant status level enhanced by KA in the cerebral cortex.ConclusionThese results suggest that pretreatment with TH has a therapeutic potential against KA-induced oxidative stress and neurodegeneration through its antioxidant effect.

Tualang Honey Protects the Rat Midbrain and Lung against Repeated Paraquat Exposure.

Paraquat (PQ) is a dopaminergic neurotoxin and a well-known pneumotoxicant that exerts its toxic effect via oxidative stress-mediated cellular injuries. This study investigated the protective effects of Tualang honey against PQ-induced toxicity in the midbrain and lungs of rats. The rats were orally treated with distilled water (2 mL/kg/day), Tualang honey (1.0 g/kg/day), or ubiquinol (0.2 g/kg/day) throughout the experimental period. Two weeks after the respective treatments, the rats were injected intraperitoneally with saline (1 mL/kg/week) or PQ (10 mg/kg/week) once per week for four consecutive weeks. After four weekly exposures to PQ, the glutathione peroxidase activity and the number of tyrosine-hydroxylase immunopositive neurons in the midbrain were significantly decreased in animals from group PQ (p < 0.05). The lungs of animals from group PQ showed significantly decreased activity of superoxide dismutase and glutathione-S-transferase. Treatment with Tualang honey ameliorated the toxic effects observed in the midbrain and lungs. The beneficial effects of Tualang honey were comparable to those of ubiquinol, which was used as a positive control. These findings suggest that treatment with Tualang honey may protect against PQ-induced toxicity in the rat midbrain and lung.

Short‐term and long‐term survival probabilities among first‐ever ischaemic and haemorrhagic stroke patients at a hospital in the suburban east coast of Peninsular Malaysia

This study aimed to determine the 28‐day, 1‐year, and 5‐year survival probabilities in first‐ever stroke patients in a relatively understudied setting: a suburban hospital that serves a predominantly rural population in the east coast of Peninsular Malaysia.