Toxicological assessment of kretek cigarettes. Part 7: The impact of ingredients added to kretek cigarettes on inhalation toxicity

Abstract

The biological activity of mainstream smoke from experimental kretek cigarettes with and without three mixes of ingredients was assessed in a 90-day rat inhalation study and in a 4-day in vivo micronucleus assay. 350 ingredients, commonly used in various combinations and in a limited number in a given brand in the manufacture of marketed kretek cigarettes, were applied at a low and a high target level to test cigarettes with a typical Indonesian blend of tobaccos and cloves. In the 90-day inhalation study, effects commonly seen in rat inhalation studies with mainstream smoke were observed. In general, no ingredients-related histopathological changes were found in the respiratory tract. In the 4-day micronucleus assay exposure of male rats to mainstream smoke from the test cigarettes containing any of the three mixes did not increase the proportions of micronucleated cells in peripheral blood and bone marrow over the proportion of micronucleated cells in the control group. Based on the results of these studies, it can be concluded that the addition of ingredients commonly used in the manufacture of kretek cigarettes did not change the overall in vivo toxicity profile of the mainstream smoke.

Cigarette smoke induced genotoxicity and respiratory tract pathology: evidence to support reduced exposure time and animal numbers in tobacco product testing

“…In the present study, histomorphological alterations regardless of the respiratory tract organ analyzed, exposure dose (1 or 2 h 3R4F CS) or length of exposure (3 or 6 weeks) were similar in male and female animals. The responses observed were comparable to other cigarette testing studies that used 3R4F (Fujimoto et al, 2015 ) or 2R4F (Schramke et al, 2014 ) reference cigarettes. A smoke concentration-dependent response was observed for the majority of histopathological endpoints assessed; as expected, responses were significantly higher in animals exposed to 3R4F CS for 2 h/day.…”

“…A reduction in percentage body weight gain was also observed only in male rats; however, differences were noted at both timepoints and both 3R4F CS doses. These data are comparable to studies where animals were exposed to CS for 90 days (Ayres et al, 2001 ; Baker et al, 2004 ; Fujimoto et al 2015 ; Potts et al, 2007 ; Schramke et al, 2014 ).…”

“…The inhalation method used in this study is based on the OECD 413 Guideline (OECD, 2009 ), a rodent nose-only sub-chronic inhalation toxicity protocol that has been used previously, with minor modifications, for the testing of cigarettes (Gaworski et al, 2009 ; Schramke et al, 2014 ). Numerous studies have detailed the effect of repeated CS exposure on body weight (Ayres et al, 2001 ; Baker et al, 2004 ; Fujimoto et al, 2015 ; Potts et al, 2007 ; Schramke et al, 2014 ). In this study, only male animal body weight was reduced following 6 weeks of exposure to 3R4F CS for 2 h/day.…”

“…The Organization for Economic Co-operation and Development (OECD) Guideline 413 (OECD, 2009 ), a rodent nose-only sub-chronic inhalation toxicity guideline, can be used with minor modifications to test both cigarettes (Gaworski et al, 2009 ; Schramke et al, 2014 ) and products that heat tobacco (Fujimoto et al, 2015 ). The OECD 413 protocol stipulates that inhalation should be for 90 days, however, CS induced pathology can be identified within the rat respiratory tract prior to 90 days (Fujimoto et al, 2015 ; Kogel et al, 2014 ; Piade et al, 2014 ; Walker et al, 1978a,b ).…”

Toxicological assessment of kretek cigarettes part 4: Mechanistic investigations, smoke chemistry and in vitro toxicity

“…The eugenol concentration measured in smoke and in filler is reduced to approximately 20% of the original content: IND-SC, a cigarette with a blend of tobaccos typical for kretek products and 370 mg spent cloves where eugenol has been added back to a concentration of approximately 80% compared to untreated cut cloves: IND-SC-E, a cigarette with tobaccos typical for kretek products with 370 mg spent cloves where the oleoresins have been added back. The eugenol concentration measured in smoke and in filler is approximately 90% of what is observed with untreated cloves: IND-SC-O, a kretek with a blend of tobaccos typical for kretek products and the addition of 370 mg untreated cut cloves per cigarette: IND-C, which is identical in design to the Kretek-R used in Part 2 and Part 3 (Piadé et al, 2014a,b), and the Control in Part 6 and Part 7 (Schramke et al, 2014) of this supplement, a cigarette with a typical American-blend of tobaccos with the addition of 370 mg untreated cut cloves per cigarette: US-C, an American-blended standard reference cigarette distributed by the University of Kentucky, USA (Davies and Vaught, 2003): 2R4F. This cigarette is considered to be representative of the 12-mg TPM segment of commercial US blended cigarettes (Chen and Moldoveanu, 2003).…”