Discussion
From the foregoing, this research is an attempt to provide scientific basis for the purported use of the Lizard dung as a substance of abuse. This study became expedient owing to the fact that available evidences in literature as at the time of embarking on the research, are low on the hierarchy of evidence in scientific researches (Borgerson, 2009), and are not sufficient to drive a strong argument. There are only case reports as well as articles in print and electronic media; describing the various methods of using lizard dung as a substance of abuse. Oral and inhalational routes of administration were reported as the means by which these abusers use whole dung or only the whitish part of the lizard dung to achieve euphoria (Jimoh et al., 2022).
In achieving the aim of this study, a quantitative analysis of the macromolecules in the whitish and darkish part of the lizard dung was carried out. The result of the proximate analysis revealed that crude protein makes up majority of the contents of the whitish lizard dung and even higher in comparison to quantities found in the darkish part. This is in agreement with findings of high urea content previously reported in Tan et al., (2020). It has been previously asserted that whitish part of the lizard dung is a composition of crystallized uric acids which is a means of excretion of nitrogenous wastes analogous to urine (Tan et al., 2020). It becomes plausible therefore, to consider the urate content as the possible psychoactive substance. This is subject to experimental verification even though Tovchiga and Shtrygol (2014) had previously confirmed the enhancement of cognitive functions and motivations upon administration of uric acid in different human population samples. Uric acid (and its analogues) penetrates the blood brain barrier, and relative to metabolism of catecholamines/dopamine, urates can be synthesized and metabolized in the CNS, therefore exhibiting potent neuroprotective and antioxidative properties (Tovchiga and Shtrygol, 2014).This findings suggest that the whitish part of lizard dung is likely more effective to elicit effects relating to CNS activities.
This study also revealed higher ash content in the darkish part than in white; and a total absence of crude fibre in the whitish part of the dung. This is in line with previous findings that lizards feeds on a broad spectrum of arthropods majorly ants, beetles and highly mobile flying insects like wasps because lizards are predators that ambush their preys (Tan et al., 2020; Burghardt, 2013). The presence of fibre in the darkish part is supportive of previous studies that showed the presence of herbaceous materials and sand particles in the stomach of lizards (Tan et al., 2020). Previous studies have established the indispensable role of Potassium in the propagation of nerve impulses (Holland, et al., 2019; Nasser et al., 2019). Along with sodium, potassium regulates the water balance and the acid-base balance in the blood and tissues, and plays a critical role in the transmission of electrical impulses in the heart. The active transport of potassium into and out of the cells is crucial to cardiovascular and nerve function (Holland, et al., 2019). The sufficient elemental potassium present in the whitish part of the lizard dung is indicative of its potential to serve a source of experimental potassium, whereby its administration would lead to a concomitant increase in serum potassium levels. A study on the link between administration of whitish part of lizard dung and increased nerve impulses becomes reasonable.
The major reason for conducting safety studies in any experimental sample is to outline the nature and significance of adverse effect and to establish the exposure level at which this effect is observed (Ugwah-Oguejiofor et al., 2019; Ibrahim et al., 2016). Acute toxicity study shows that the aqueous preparation of whitish and darkish part of lizard dung administered through oral route to rats at 1600, 2900 and 5000 mg/kg using Lorke’s (1983) method of acute toxicity testing did not produce any sign of toxicity and death in the animals. The OECD criteria for testing chemical substances and mixtures, under its Globally Harmonised Classification System (GHS), substances with LD50 >5000 mg/kg are categorised as unclassified or category 5 (Organization for Economic Development, 2001). This suggests that the oral LD50 of the lizard dung being greater than 5000 mg/kg may be safe. Similar suggestion could be made for inhalation administration of whitish and darkish part of lizard dung. Results from acute toxicity studies often have a limited application in clinical practice. Hence, we proceeded to sub-acute toxicity study.
Substances of abuse, (like psychoactive faunas) are similar to drugs administered in chronic disease conditions; often need repeated application and hence, toxicological evaluation (sub-acute toxicity study) since daily use may result in accumulation in the body with progressive effects on vital tissues and organs (Ugwah-Oguejiofor et al.,, 2019; Bariweni et al., 2018). Testing for sub-acute toxicity is an important approach taken to assess target organ and haematological or biochemical effects of test samples since these effects are usually not evident in data from acute toxicity study. It is also a progressive step required in establishing safety of such substances in human.
Analyses of hematological parameters are used to study the extent of toxicity of drug substances (Ibrahim et al., 2016) including psychoactive faunas like lizard dung. Understanding the alterations in the biological system responsible for blood cell formation (haematopoiesis) have a higher predictive value for human toxicity when data are translated from animal studies (Olson et al., 2000). An erythrocyte (RBC), a leukocyte (WBC), or a thrombocyte (platelet) is believed to be derivable from an immature pluripotential stem cell, (Ugwah-Oguejiofor et al., 2019).In this study, the oral and inhalational administration of whitish and darkish parts of lizard dung in rats for a period of 28 days produced no significant change in all blood parameters that was analysed in this study.
It is already established that the kidney and liver play significant roles in metabolism, digestion, detoxification, and elimination of substances from the body. Therefore, testing for derangement in normal serum levels of their biochemical biomarkers gives an important guide into the health of the liver and kidney; and crucial in the toxicological evaluation of available xenobiotics (Ugwah-Oguejiofor et al., 2019; Bariweni et al., 2018). Serum electrolytes, urea and creatinine are widely requested blood test to ascertain the functionality of the kidneys. In the current study, only the serum urea and creatinine levels where analyzed as a source of insight into kidney health status. Results from this study showed that out of a total twelve (12) experimental groups (of both routes of administration), six (50%) of the experimental groups (doses) demonstrated significant difference (p < 0.05) of serum urea levels compared to the negative control. Over 83% of significantly different observations were a significant reduction of serum urea levels in comparison to the negative control group. Reduced plasma/serum urea is less common (Higgins, 2016) and usually of less clinical significance than its increase (Ugwah-Oguejiofor et al., 2019). Low urea levels are seen in acute liver failure or overhydration and malnutrition (Ugwah-Oguejiofor et al., 2019). The animals were fasted before euthanasia and collection of blood samples and hence urea levels are expected to be elevated as reported previously in Hassan et al., (2018). Only the inhalation of 2.0g of darkish part of lizard led to an elevated serum urea levels. Creatinine clearance is an indicator of glomerular filtration rate that assesses kidney function. Significant elevation in levels of serum creatinine was observed after 28-day inhalation of whitish and darkish arts of lizard dung. The oral administration led to no significant change. Although the histology of the kidneys in rats that received inhalation did not produce any pathological changes and supporting the safety of the sample in the kidney, elevated serum creatinine levels are observed in this study could be a pointer to degeneration in glomerular filtration rate
Primary biochemical liver function tests provide information about the status of the liver (Lala, et al., 2022). Bilirubin is a well-established marker that is routinely included in biochemical tests for patients with liver dysfunction or any other condition. However, bilirubin is not a sensitive or specific marker of liver function, so a careful interpretation of test results is necessary for accurate inferences (Guerra Ruiz et al., 2021). Alkaline phosphatase are widely distributed enzymes (e.g., liver, bile ducts, intestine, bone, kidney, placenta, and leukocytes) that catalyze the release of orthophosphate from ester substrates at an alkaline pH (Sharma et al., 2014). Aminotransferase includes the Aspartate aminotransferase (AST) and the alanine aminotransferase (ALT) that are the biomarkers of hepatocellular injury.These enzymes participate in gluconeogenesis by catalyzing the transfer of amino groups from aspartic acid or alanine to ketoglutaric acid to produce oxaloacetic acid and pyruvic acid, respectively (Lala, et al., 2022). AST is present as cytosolic and mitochondrial isoenzymes and is found in the liver, cardiac muscle, skeletal muscle, kidneys, brain, pancreas, lungs, leucocytes, and red cells (Robles-Diaz,et al., 2015; Kalas et al., 2021, Lala et al., 2022). It is not as sensitive or specific for the liver as ALT, and elevation in AST may be seen as secondary to nonhepatic causes (Robles-Diaz,et al., 2015). By implication, high serum levels of liver enzymes are signs of hepatocellular toxicity (Lala et al., 2022) whereas a decrease may indicate enzyme inhibition (Akanji et al., 2013). Bilirubin (Total and Direct), ALP, ALT and AST were analyzed as the biomarkers of liver health condition after 28-day sub acute study
Overall, there was no significant change in the serum levels of Bilirubin after the study. Bilirubin is the end product of heme catabolism, with 80% derived from hemoglobin (Lala, et al., 2022). This finding conforms to the insignificant change in serum haemoglobin already reported in this study. Oral and inhalation application of lizard dung showed a decrease in serum levels of ALP. This is less common, moreover Alkaline phosphatase assays are susceptible to negative interference because alkali denaturation of hemoglobin may cause a negative offset in absorbance readings (Lala, et al., 2022).The sub acute toxicity study showed a significant decrease in serum levels of ALT which in conjunction with the histological results, suggests no significant change in the health state of the liver. The result of AST assay also showed a significant reduction in serum levels in comparison to the negative control.
Available case reports on the abuse of lizard dung (Danjuma et al., 2015; Chahal et al., 2016) did not specify durations of usage. It becomes noteworthy therefore, to assert that a typical substance abuser would not stop after 28- days. The usage of lizard dung could persist for months and years especially as these substances are easily available at almost no cost and are no legal framework militating against the usage Orsolini et al., 2018; Zhang et al., 2019). The absence of signs of toxicity observed (after this 28-day study) in hematological parameters and after histological studies of the kidney, livers and hearts may not be conclusive on the overall safety of the oral and inhalational administration of lizard dung because a longer duration of toxicity study (say 120-180days), would appropriately replicate its real life duration of usage, and as such, more likely to provide a stronger evidence about the toxicity profiles of the use of lizard dung as a substance of abuse.
Previous studies have established chronic inflammation as a major player in lung cancer (Gomes et al., 2014; Cho et al., 2011; Yanbaeva et al., 2007; O’Callaghan 2010). Histological examination of sections of the lungs of the groups that received the whitish and darkish part of the lizard dung via the inhalational route revealed the presence of mixed inflammatory infiltrates, acute or chronic inflammation with associate edema and occasional heamorrhage in keeping with chronic irritation. This could be suggestive of the initiation of lung fibrosis and a possible progressive of lung cancer. Animal models for central nervous system activities are an attempt to reproduce features of human CNS behaviours in laboratory animals. Assumptions are often made in theory that a model should reproduce all the features of the CNS being studied. Unfortunately this is hardly achieved due to the complex manifestation of psychiatric responses and the huge disparity between the human and laboratory animal cognition. The whitish and darkish parts of lizard dung was evaluated (after oral and inhalational routes)for CNS activities in rats using tail suspension and forced swim tests (antidepressant-like effect), hole board and elevated plus maze tests (anxiolytic-like effect) and sodium pentobarbital-induced sleeping time test (sedative effect).
Forced swim and tail suspension tests placed rats in an inescapable and stressful situation, an action that produces a mental condition of hopelessness and despair behaviour that could be accounted for in the form of immobility duration (Sofidiya et al., 2022). Immobility or despair behaviour produced in both forced swim and tail suspension tests are taken as a prototype of depression which reflects the behavioural despair seen in depressive people. In general, the immobility response is reduced by administration of antidepressant drugs and other treatments that are therapeutically effective in depression (Lucki, 2010). The test sample reduced immobility time in the two tests after oral and inhalational administrations suggesting CNS depression. In the tail suspension test, the reduction in duration of immobility seen in the groups that inhaled 1.0g and 2.0g of the whitish part of lizard dung was also significantly different from and comparable to the reduction by imipramine standard. In a similar observation, the experimental groups that received inhalation of 1.0g and 2.0g of the darkish part of lizard dung before forced swim test , significantly reduced duration of immobility in comparison to the negative control and comparable extent to the imipramine group. This suggests anti-depressant activity and that inhalational administration is more effective than oral administration, therefore explains why abusers usually smoke/inhale the lizard dung (Jimoh et al., 2022).
In the elevated plus maze, anxiety may be represented by avoidance of the open arms by an animal placed in the maze. CNS depression manifesting as anxiolytic-like effect (calmness) is revealed by the increase of the time spent by the animals in the open arms. The animals pre-treated oral and inhalational doses of the extract in this experiment significantly increased the entry and time spent in the open arms suggesting anxiolytic like effect (Sofidiya et al., 2022). The Hole board test assesses anxiety, emotionality and response to stress (Wegener and Neigh 2021). A significant reduction in head dips during the test is reported as a measure of CNS depressant activity (Wegener and Neigh 2021). Oral and inhalational administration of lizard dung, especially the of the whitish part significantly reduced the number of head dips during the exploratory behavior of the rats in the hole board apparatus, also suggesting CNS depression.
The potentiation of phenobarbital-induced sleeping time is used to evaluate the possible sedative-hypnotic effect of agents (Sofidiya et al., 2022). The depression of the central nervous system of the lizard dung was also evident by the potentiation of phenobarbital-induced hypnosis in a dose-dependent manner after oral and inhalational co-administration of the whitish and darkish parts of lizard dung and phenobarbitone.. It is possible that the test sample could act via the central mechanisms involved in sleep regulation or by blocking the metabolism of phenobarbital (Howlader et al., 2017).