Data with different letters are significantly different at extract (A) and quantitative analysis of viable cells (Q3) (B), early apoptosis cells (Q4) (C), and late apoptosis cells (Q2) (D). than A549 cells for both curcuminoid extract and nanoemulsion treatments. Growth of BEAS-2B remained unaffected for both the curcuminoid extract and nanoemulsion treatments, with a concentration range from 1 to 4 g/mL. Also, the activities of caspase-3, caspase-8, and caspase-9 followed a dose-dependent increase for both A549 and H460 cells for both the Tmem33 treatments, accompanied by a dose-dependent increase in cytochrome C expression and a dose-dependent decrease in CDK1 expression. Interestingly, a dose-dependent increase in cyclin B expression was shown for A549 cells for both the treatments, SB-423557 while a reversed trend was found for H460 cells. Both mitochondria and death receptor pathways may be responsible for apoptosis of both A549 and H460 cells. Linnaeus, lung cancer cell, cell cycle, apoptosis mechanism Introduction Linnaeus, a vital medicinal herb widely produced in Asian countries such as India, the Peoples Republic of China, and Malaysia, has received considerable attention in the past 2 decades due to its possible clinical use in the treatment of chronic diseases such as diabetes, inflammation, cancer, and Alzheimers disease.1 The major bioactive compound present in dried roots and stems of L. is usually curcuminoid, which SB-423557 contains curcumin, demethoxycurcumin, and bisdemethoxycurcumin, with curcumin being the most abundant ingredient.2 However, as curcuminoid is insoluble in water and susceptible to degradation under light and alkaline conditions, its application in food and drug industries is limited.3 In addition, the extremely low bioavailability of curcuminoid in vivo also affects its therapeutic efficiency in chronic diseases,4 questioning SB-423557 the use of curcuminoid as a botanic drug. According to a statistical report issued by the Ministry of Health of Taiwan in 2014, malignant tumor associated with lung cancer, is the leading cause of death in Taiwan.5 On the basis of biological characteristics and clinical performance, lung cancer can be divided into small-cell lung cancer and non-small-cell lung cancer, with the former accounting for 12%C15% and the latter for 85%C88% of the cases.6 Comparatively, small-cell lung tumors grow and spread faster to the brain, skeleton, and lymph organs than non-small-cell lung tumors, with the former being more allergic to chemical and radiation therapies.7 Non-small-cell lung cancer can be further divided into adenocarcinoma, squamous cell carcinoma, and large cell carcinoma. Large cell carcinoma is the most difficult to treat due to its possible presence in any spot of the lungs as well as fast growth and migration.8 Numerous reports have been published regarding the biological activities of curcuminoid, especially curcumin SB-423557 standard. However, the effect of curcuminoid nanoemulsion on inhibition of cancer cell growth was less explored. Among the various curcuminoids, curcumin was shown to be the most efficient in scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH)-free radicals, with IC50 being 28.2 g/mL.9 Also, curcumin possessed anti-inflammatory activity through expression regulation of NF-kB, COX-2, inducible nitric oxide synthase, pro-matrix metalloproteinase, and tumor necrosis factor-.10 More importantly, curcumin could inhibit proliferation and migration of various cancer cells, as well as enhance expressions of P21, P27, and P53 of breast cancer cells with cell cycle arrested at G1 phase.11,12 Similarly, in an animal experiment, curcumin was found effective in reducing bladder tumor volume through decrease of cyclin D, VEGF, COX-2, C-myc, and BcL-2 expressions.13 Similar outcome was observed in a breast cancer mice model by Kang et al14 who demonstrated that curcumin could suppress tumor growth and potentiate the growth inhibitory effect of paclitaxel when combined with curcumin. All these findings suggest that curcumin possesses a great potential to be used as a chemotherapy agent. Over the past 2 decades, nanotechnology has emerged as a new technology with wide application in product development in both SB-423557 food and pharmaceutical industries, especially the development of nanoemulsion with a size between 10 and 100 nm. It has been well established that nanoemulsion possesses the ability to encapsulate bioactive compounds for enhancement of water-soluble ability, stability during storage, as well as bioavailability in vivo.15,16.