嚼食檳榔是國人相當普遍的一種習性，而且有日益嚴重的趨勢。根據文獻指出，嚼食檳榔對口腔組織包括牙齒、牙齦及口腔黏膜均有明顯不良的影響，進而可能引發癌前期病變（如：白斑症、黏膜下纖維化症）與口腔癌。但直至目前，有關檳榔成分引起口腔病變之真正機轉仍不清楚。本研究之目的是以細胞培養的方法，來分析檳榔生物鹼－Arecoline與Arecaidine對口腔頰粘膜與牙齦纖維母細胞生長之影響，進而探討檳榔生物鹼在口腔病變發生上所可能扮演的角色。實驗中，分別採用MTT比色法與BrdU標定法測量細胞增值與DNA合成情形。結果顯示：(1)頰粘膜與牙齦纖維母細胞之形態相似，且兩種細胞對Arecoline與Arecaidine之反應形式相近。(2)Arecoline與Arecaidine有刺激纖維母細胞增殖與DNA合成之作用，但當Arecoline濃度為100μg/m l時，則具有細胞毒性。(3)各細胞株之間，對Arecoline或Arecaidine感受性仍有些微差異。由以上結果，我們推測檳榔生物鹼一Arecoline與Arecaidine對口腔纖維母細胞之刺激生長與細胞毒性作用，可能與口腔病變之發生有密切關系。至於其確切角色，則仍有待進一步的研究。 Betel quid chewing habits are commonly seen in the people of Taiwan and the prevalence of betel quid chewing is increasing gradually. Many investigators have suggested that betel quid chewing has a untoward effect on the tissues of the oral cavity, including teeth, gingiva and oral mucosa. Furthermore, it has been reported that, compared with those who do not chew betel quid at all, the risk of oral precancerous lesions (e. g. leukoplakia and oral submucous fibrosis) and oral cancer are higher among those who chew betel quid; however, the relative risk associated with each ingredient used in the quid has not been established clearly. In the present study, we investigated the effects of betel nut alkaloids (arecoline and arecaidine) on the cell proliferation and DNA synthesis of oral fibroblasts which were obtained from healthy oral buccal mucosa and healthy gingiva. The results could be summarized as follows: (I)There was no difference in cellular morphology of fibroblasts from the buccal mucosa and gingival tissues, and the patterns of cellular response to arecoline and arecaidine were similar between the two kinds of oral hbroblasts.(2)With the exception for arecoline which was cytotoxic at 100 μg/ml, we found that arecoline and arecaidine can stimulate cell proliferation and DNA synthesis of the oral fibroblasts. (3)There were some variations in the response to arecoline or arecaidine among all of the cell lines. Such findings imply that there are stimulations of cell growth of human oral fibroblasts in vitro by betel nut alkaloids. However, the exact role between the oral lesions and betel nut alkaloids needs to be investigated further.