Cigarette smoking is one of the health problems at global level that impacts various biological systems including liver. The main objectives of this study were to investigate both cigarettes smoking impacts on liver function tests and the potential therapeutic use of Ammi vinaga to counteract the cigarette smoking impacts. Cigarette smoking animal model was developed by using rats and exposing them to smoking in digital smoking machine. Rats were exposed to cigarette smoking for one month, followed by a recovery period of one month so
 that smoking was quitted. Results showed that cigarette smoking increased liver function tests. Both recovery and Ammi visnaga use were likely to lower the impacts of smoking, particularly the use of Ammi visnaga in the recovery stage. Taken together, the use of Ammi visnaga to counteract the adverse effects of smoking is promising.

Tobacco smoking is still one of the top causes of death in the United States, with more than 480,000 fatalities each year (Nabi-Burza et al., 2021). The damaging consequences of tobacco smoke on persons who are exposed to it have also been extensively documented (Nabi-Burza et al., 2021). Tobacco use, in any form, can be regarded as a behavioral process that causes consumers to develop a psychological and physiological addiction. Tobacco's primary element, nicotine, is highly addictive, leading to long-term tobacco usage. Tobacco products are classified as combustible or noncombustible. Cigarettes, cigars, cigarillos, little cigars, water pipes (hookah), and pipes are all combustible tobacco products. Electronic cigarettes and tobacco compositions designed for chewing, dipping, or snuffing are examples of noncombustible tobacco products (Onor et al., 2017).

Lactate dehydrogenase is a type of enzyme that breaks down lactate (LDH) Lactate Dehydrogenase (LDH) is an enzyme that is essential for the conversion of sugar into energy for cells to operate. LDH is found in the liver, heart, pancreas, kidneys, skeletal muscles, lymph tissue, and blood cells, among other organs and tissues in the body. LDH may be released and raised in the blood when the body is subjected to oxidative stress or injury (Chernecky and Berger, 2013). A high level of LDH in the blood indicates acute or chronic cell damage; abnormally low levels of LDH occur infrequently and are usually not considered harmful; high levels of LDH indicate a variety of conditions, including stroke, cancer, heart attack, blood flow deficiency, hemolytic anemia, hepatitis, muscle injury, and tissue death (Masella et al., 2005; Raddam et al., 2017). Several studies have reported as association between increased levels of LDH and smoking (Robert et al., 1988; Pannuru et al., 2009; Madole et al., 2016; Muhsin et al., 2021).

Cigarette smoking appears to impact the liver, with various toxins in cigarettes changing enzymatic and inflammatory pathways in hepatic physiology, according to basic and clinical research (Avti et al., 2006). Smoking is a risk factor for liver cancer (Wannamethee, Gerald Shaper, 2010), has been linked to an increased risk of cirrhosis, and may slow the progression of chronic liver illnesses (Wannamethee, Gerald Shaper, 2010). 

Ammi visnaga L. is a Mediterranean short annual or biennial herb native to North Africa, Asia, and Europe (Khalil et al., 2020). Many people and companies cultivate it in order to utilize its extracts or active components in the pharmaceutical sector. At heights of 380–460 meters above sea level, it was recently discovered and added to the flora of Croatia (Khalil et al., 2020). The plant can also be found all throughout North America (North Carolina, Pennsylvania, Oregon, Alabama, California, Florida, and Texas). The plant, particularly its fruit, has a wide range of traditional and modern medical benefits. Despite the plant's medical relevance and usage, no extensive literature assessment of A. visnaga and its chemical contents has been conducted. (Khalil et al., 2020). 

The main objectives of the present study were to investigate the impacts of using Ammi visnaga on liver function tests of smoking rats.

Two groups of rats (N=8) were randomly assigned as Group (1), a negative control group that was solely exposed to fresh air, while Group (2) was exposed to smoking (red LM cigarettes) for 30 days at a rate of one cigarette per rat per day. As a recovery stage from the effects of cigarette and waterpipe smoking, a one-month period of non-exposure (cessation) to smoking was followed. 

A digital smoking apparatus was designed that have a special smoking topography, suitable for the exposure of rats to cigarette smoke (Shraideh, et al., 2011). The smoking machine is composed of the following components as illustrated in (Figure 1). Inhalation chamber made of Plexiglas (8 mm thick) with the dimensions 30 cm length × 22.5 cm width ×10.5 cm height   that can host five rats weighting 100-150 gm.

Each cycle of smoking run lasted for 90 seconds and consisted of the three following steps:

a.     Continuous withdrawing of cigarette smoke for 30 seconds. 

b.     Washing out of the smoke for 30 seconds, with fresh air.

c.     Finally, rats were allowed to breath normal fresh air for 30 seconds.

Figure 1: Five rats placed in the digital smoking machine and exposed  to the smoke of 5 cigarettes

Following obtaining blood samples from all rats in the study groups, liver function tests were measured in medical laboratories in the local market. 

The Effect of Ammi visnaga Seeds on Liver Enzymes of Rats Exposed to Chronic Smoking

The following tables showed the statistical analysis of three serum liver 

enzymes activity (ALT, AST, and LDH level), following chronic exposure to waterpipe and cigarette smoking, and after cessation during treatments with Ammi visnaga seeds. (Data are expressed as Mean ± SEM of 8 rats). As shown in table (1), Ammi visnaga insignificantly lowered the level of ALT from 51± 3.2 U/l in control group to 46± 8.2 U/l in Ammi visnaga treated group (p=0.57). After cessation period, Ammi visnaga significantly lowered the level of ALT 33± 8 U/L (p=0.006). 

Table 1: Effect of Ammi visnaga seeds on ALT level in albino rats.
*Mean significant P<0>
** Mean not significant P>0.05.

As shown in table (2), the levels of AST were close to each other in control group and cigarette and Ammi visnaga group (p=0.98). After cessation period, Ammi visnaga significantly reduced the level of AST from 222±7.5 U/L to 104±10.8 U/L (p=0.02).

Table 2: Effect of Ammi visnaga seeds smoke on AST level in albino rats.

As demonstrated in table (3), the level of LDH in control group was 186±1.2 U/L and this was significantly increased in cigarette and Ammi visnaga 202±4.0 U/L (p=0.03). Following the cessation period, the level of LDH was 324± 7.6 U/L (p=0.000). 

Table 3: Effect of Ammi visnaga seeds smoke on LDH level in albino rats.
*Mean significant P<0>

In this study, we investigated the impact of using Ammi visnaga on liver function tests as a therapeutic model. Compared with control group, cigarette smoking increased the levels of ALT, AST, and LDH (figure 2).

Figure 2: Smoking model showing variations in liver function tests

The levels of ALT were significantly elevated from 51± 3.2 U/l in control group to 71± 2.3 U/l in cigarette smoking group (p=0.000). Following smoking cessation, the level of ALT significantly lowered to 33 ± 4.2 U/l (p=0.001). Treatment with Ammi visnaga seeds reduced the level of ALT (46± 8.2 U/l), but not significantly (p=0.57). Smoking cessation with continuous treatment with Ammi visnaga seeds insignificantly reduced the level of ALT (33 ± 8.0 U/l, p=0.006).  The same trend was observed with treatment with both ascorbic acid and allicin extract. These results indicated the adverse effects of cigarette smoking on liver and are consistent with previous studies in which the level of ALT increased significantly because of cigarette smoking (El-Zayadi, 2006; Wannamethee and Shaper, 2010). The use of herbal treatment was reported in diseases such as Ammi visnaga seeds which was used to treat different diseases including liver disease (Vanachayangkul, 2008). The study findings regarding vitamin C confirmed that reported by Helen and Vijayammal, (1997) and showed the protective effect of Vitamin C on rat liver cells injured by smoking.

The level of AST significantly increased in cigarette smoking group, and restored to normal physiological level, and decreased further significantly after cessation period. The same trend was observed for LDH. It is obviously shown that Ammi visnaga can be used to reduce the toxic effects of cigarette smoking. 

Cigarette smoking has adverse health effects as can be seen in increasing the levels of liver function tests: ALT, AST, and LDH. The use of Ammi visnaga to counteract the smoking effects on liver function tests is promising.