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Scientific studies on the impact of wood species on solid fuel production, performance, and sustainability are grossly inadequate. The knowledge of this is imperative as users of solid fuels are increasing rapidly, especially in Africa. On this note, it becomes necessary to explore measures that will improve its efficiency and sustainability as an energy source. This study investigates some properties of selected wood species used as an energy source in Nigeria and their pelleting potential. Nine samples were characterized and assessed for suitability of pelleting following four wood pellet quality standards. The properties investigated are physical (moisture content and density) and thermochemical (calorific value, ash content, volatile matter, fixed carbon, and ultimate properties (carbon, nitrogen, hydrogen, oxygen, sulfur, arsenic, cadmium, and lead)). These were selected because they are among the most important pellet parameters contained in the quality standards. The findings revealed a net calorific value between 10.61 MJ.kg−1 for Tectona grandis and 18.44 MJ.kg−1 for Eucalyptus cam. The ash content, volatile matter, and fixed carbon contents of the samples range between 2.1 and 24.4%, 65.94 and 87.77%, and 3.51 and 18.63%, respectively. Anogeissus leiocarpus was found to be the species with the best rating score in terms of fuel properties, while Vitellaria paradoxa was the lowest. However, in terms of conformity with the four wood pellet standards, Khaya senegalensis, Parkia biglobosa, and Eucalyptus cam., having presented density, calorific value, sulfur, arsenic, cadmium, and lead within the limits of the wood pellet quality standards, were considered the best wood species in terms of fuel suitability and pelleting potential. The findings therefore suggest that not all wood species are suitable as fuel. Thus, for species that do not meet the standard wood pellet requirements, alternatives such as the use of biomass blends, additives, or process adjustments can be employed to adapt the quality to the standards or by using the fuels in improved cookstoves. [ABSTRACT FROM AUTHOR]

Background and Purpose: Kratom is a preparation from Mitragyna speciosa, which is used as a natural drug preparation for many purposes around the world. However, an overdose of Kratom may cause addiction‐like problems including aversive withdrawal states resulting in cognitive impairments via unknown mechanisms. Its main psychoactive alkaloid is mitragynine, showing opioid‐like properties. Experimental Approach: Here, we analysed the neuropharmacological effects of mitragynine compared with morphine withdrawal in rats and searched for a pharmacological treatment option that may reverse the occurring cognitive deficits that usually aggravate withdrawal. Key Results: We found that withdrawal from 14‐day mitragynine (1–10 mg·kg−1·day−1) treatment caused dose‐dependent behavioural withdrawal signs resembling those of morphine (5 mg·kg−1·day−1) withdrawal. However, mitragynine (5 and 10 mg·kg−1·day−1) withdrawal also induced impairments in a passive avoidance task. Mitragynine withdrawal not only reduced hippocampal field excitatory postsynaptic potential (fEPSP) amplitudes in basal synaptic transmission and long‐term potentiation (LTP) but also reduced epigenetic markers, such as histone H3K9 and H4K12 expression. At the same time, it up‐regulates HDAC2 expression. Targeting the epigenetic adaptations with the HDAC inhibitor, SAHA, reversed the effects of mitragynine withdrawal on epigenetic dysregulation, hippocampal input/output curves, paired‐pulse facilitation, LTP and attenuated the cognitive deficit. However, SAHA amplified the effects of morphine withdrawal. Conclusion and Implications: The data from this work show that changes in histone expression and downstream hippocampal plasticity may explain mitragynine, but not morphine, withdrawal behaviours and cognitive impairments. Thus, it may provide a new treatment approach for aversive Kratom/mitragynine withdrawal and addiction. [ABSTRACT FROM AUTHOR]

Introduction: Terminalia catappa (T. catappa) leaves are used in the treatment of hypertension, diabetes, cough, jaundice, indigestion etc, while the bark is used to treat diarrhea, dysentery, abscesses etc. Due to the acceptance and increased use of medicinal plants in pregnancy, there is a need to evaluate their toxicological profiles in pregnancy for safe use. This study aims to evaluate the toxicological effects of aqueous leaf extract of T. catappa in pregnant rats. Methods: acute toxicity study was carried out using Organization of Economic Corporation Development (OECD) 423 guidelines. Seventy-five rats (50 females and 25 males) were used at the age of 2 weeks just after weaning. The male rats were separated from the female rats in different cages and allowed to mature for 10 weeks. Then the rats were allowed to mate. After mating, 20 female rats with viable spermatozoa counts were selected and divided into 4 groups of 5 rats each (n=5). The control group received distilled water while the treatment groups II, III, and IV were administered with aqueous leaf extract of T. catappa orally at graded doses of 100, 200, and 400 mg/kg respectively for 21 consecutive days. The daily food and water intake, and weight were recorded. On the 22th day, the rats were anesthetized by chloroform inhalation, and blood samples were collected for haematological and biochemical analysis. The maternal livers, kidneys, and hearts were collected and weighed, and histological studies were carried out. The fetuses were removed and examined. An isolated tissue experiment was carried out on the myometrium of the pregnant rat uterus. The isometric reading of the uterine contractions was recorded. Results: the oral LD50 was found to be ≤2000-5000 mg/kg. There was a significant (p<0.05) increase in the mean food intake at the 100, 200, and 400 mg/kg doses of the extract used on the 14th and 21st days when compared to the 7th day. The renal function test showed a significant (p<0.05) increase for chloride. The liver function test revealed that the extract at 100 mg/kg dose, significantly (p<0.05) increased only Alkaline Phosphatase (ALP) liver enzyme, while at 200 mg/kg dose, only AST liver enzyme was significantly (p<0.05) increased, while at 400 mg/kg dose, ALT, AST, ALP, and albumin increased significantly (p<0.05) when compared to the control group. There was a significant (p<0.05) decrease in the relative organ weight of the liver at 400 mg/kg dose of the extract. The liver histology showed moderate hepatic vacuolation and necrosis, while the histology of the kidney showed slight tubular necrosis. Conclusion: this study has shown that the aqueous leaf extract of T. catappa is relatively not safe in the pregnant rats. Although it is non-toxic to the fetus, it exhibited tocolytic effect by inhibiting uterine contractions, thus it should be used with caution during pregnancy, especially in the third trimester or during labor. [ABSTRACT FROM AUTHOR]

Introduction: Drug addiction changes the normal structure and functions of the brain, which may lead to memory deficit that requires urgent interventions. Mitragynine, the major indole alkaloid from Mitragyna speciosa has been used as a recreational drug and ‘herbal high’ preparation in Southeast Asia and Western countries due to its opium and coca-like effects. However, there are insufficient data regarding the effects of long-term exposure to mitragynine on addiction and cognitive behavior. Thus, in this study, effects of repeated exposure to mitragynine on withdrawal signs and cognitive functions were evaluated. Methods: Animals were treated (intraperitoneally) daily with mitragynine (1, 5, 10 and 30 mg/kg) for 14 days. Twenty-four (24) hours after the last dose, animals were examined for behavioral signs using global withdrawal scoring and the effect on cognitive behavior was determined using passive avoidance task. Results: One way ANOVA revealed that, mitragynine at the doses of 5, 10 and 30 mg/kg produced a significant (P < 0.01) and dose dependent increase in the behavioral “counted signs” and a non-dose dependent increase at all the doses tested (1, 5, 10 and 30 mg/kg) in “checked signs” (squeaking on touch and hostility on handling) as compared to control. A significant (P < 0.01) dose dependent increase in the mean aggregate withdrawal signs was found in all the doses tested when compared to vehicle. At the doses of 5, 10 and 30 mg/kg, mitragynine significantly (P < 0.001) reduced the step through latency as compared to control in passive avoidance task. Conclusion: Data from this study showed that mitragynine at high dose possessed abuse liability leading to cognitive decline. However, mitragynine at lower dose (1mg/kg) was found to be safe without cognitive decline. Hence, the use of mitragynine at high dose as a “herbal high” is justified. [ABSTRACT FROM AUTHOR]