Excessive alcohol consumption causes a number of health challenges with socio-economic consequences (Souza et al., 2017). Alcohol has a pleasant subjective effects (Karlsson and Roman, 2016), which reinforce its consumption and play a pivotal role in the onset of alcohol-related diseases (Hendler et al., 2013). Alcoholic liver disease is one of the most common causes of chronic liver disease worldwide. Individuals who perceive the drug as more rewarding and less aversive may be at higher risk for alcohol-related diseases (Schuckit et al., 2004; Hendler et al., 2013). Depending on dose and time, alcohol produces both stimulatory and depressant effects on behavior subjects (Brabant et al., 2014; Karlsson and Roman, 2016). The negative effects of alcohol consumption depend on the amount consumed, time of exposure and drinking pattern (WHO, 2014; Souza et al., 2017). Ethanol is the major constituent of alcoholic beverages and it is the chemical responsible for alcohol addiction and alcoholism (Garcia et al., 2015). Ethanol acts as a toxic substance to vital organs of the body including liver, brain, kidney and heart (Lieber, 1988; Garcia et al., 2015).
The liver is highly susceptible to injurious attack by offending xenobiotics as it plays a pivotal role in the removal of substances from portal circulation (Bodakhe and Ram, 2007). Moreover, the liver sustains the greatest amount of organ damage from excessive alcohol use, as the metabolism of alcohol occurs primarily in the organ (Lieber, 2004). The metabolism of ethanol results in oxidative stress. Ethanol disrupts the delicate balance between the pro- and anti-oxidant system of the body, culminating in oxidative stress (Lieber, 1988; Garcia et al., 2015). Ethanol induces the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) and in their high levels may cause necrosis of liver cells (Hou et al., 2010; Shi et al., 2017)
The use of natural products for medicinal purposes by diverse peoples and cultures of the world is as old as mankind (Christophersen et al., 1991; Van Wyk and Gericke, 2000; Dewole et al., 2013; Dah-Nouvlessounon et al., 2015). Honey is one of the oldest known natural products with medicinal properties. Honey is widely accepted to be beneficial to health and it has been traditionally used both in the Middle East and Africa as a curative substance for a number of human illnesses including signs and symptoms of Upper Respiratory Tract Infections (URTIs), especially coughing (Shadkam et al., 2010; Raeessi et al., 2014). Contemporary scientific researchers have affirmed the multiple functions of honey. Honey has antimicrobial, cardio-protective and gastric protective properties (Gharzouli et al., 2002; Nasuti et al., 2006; Alvarez-Suarez et al., 2010). Honey improves blood profiles, heals wounds and ameliorates oxidative stress and risk factors of metabolic and cardiovascular diseases (Molan, 1999; Chepulis, 2007; Ajibola et al., 2012). The medicinal properties of honey has been linked with its chemical constituents including its richness in monosaccharides (fructose and glucose) and antioxidants such as phenols, ascorbic acid and flavonoids (Raeessi et al., 2014; Garciaa et al., 2015; Shi et al., 2015; Zhao et al., 2017). Besides, honey is made up of colloidal suspended particles in form of protein materials, enzymes (invertase, catalase and diastase), wax particles, pollen grains, silica, and other extraneous matter (Root et al., 2005). Kolanut (Cola nitida) is among the highly used medicinal plants in Africa (Dah-Nouvlessounon et al., 2015). It is an essential commodity in social and ceremonial events of Africans (Dewole et al., 2013; Dah-Nouvlessounon et al., 2015). Kolanut is commonly used by many people as a stimulant; it prevents sleep, thirst, and hunger and acts as an antidepressant (Lowor et al., 2010; Dewole et al., 2013; Muhammad and Fatima, 2014). Kolanut is applied industrially in the manufacture of dyes, wines, candies, drugs and soft drinks such as pepsi cola and coca cola (Javies, 2002; Ayebe et al., 2012; Dah-Nouvlessounon et al., 2015). Kolanut (Cola nitida) is made up of two percent caffeine and contains a wide variety of complex secondary plant metabolites and antioxidants including phytochemicals like phenols and flavonoids (Javies, 2002; Ayebe et al., 2012; Dah-Nouvlessounon et al., 2015). Both honey and kolanut have separately been found to be antimicrobial agents and confer protection against free radical-induced damage (Alvarez-Suarez et al., 2010; Dah-Nouvlessounon et al., 2015). Whereas honey has been found to produce anti-intoxication effects and prevent alcohol-induced liver damage (Gharzouli et al., 2002; Garciaa et al., 2015; Zhao et al., 2017), no previous study has been carried out to ascertain the effect of Cola nitida on alcohol-induced liver damage. More so, there are no previous reports on the treatment of alcohol induced liver damage by combining kolanut and honey. Therefore, this present study was designed to evaluate the effects honey and Cola nitida will produce separately on alcohol-induced liver damage as well as the treatment impact of combining both on alcohol induced liver damage.