## 3 Results  
### Antiproliferative Activity  
In the present study, the efficacy of the extracts of Habanero pepper using an SRB assay, a method applied by the National Cancer Institute's (USA-NCI) compound screening program, was evaluated [28]. According to the National Cancer Institute Plant Screening Program, a crude extract has in vitro cytotoxic activity if the IC\({}_{50}\) value is \(\leq\)20 \(\upmu\)g mL\({}^{-1}\) after incubation for 48 and 72 h [31; 32]. Based on this scale, all the extracts obtained in the present study were noncytotoxic against HeLa, MCF-7, HCT-116, HCT-15, and Caov-3 cancer cell lines, and the 184B5 breast normal cell line, except for the sample of leaves of _C. chitines_ grown on black soil obtained by maceration with methanol (LBS ME), which exhibited cytotoxic activity against the HCT-15 cell line with IC\({}_{50}\) = 16.23 \(\pm\) 2.89 \(\upmu\)g mL\({}^{-1}\) (Figure 2). It was also categorized as highly active according to the criteria proposed by [PERSON] et al. [33] by evaluating the cytotoxic activity of plant by-products against human breast cancer cell lines. Additionally, the results revealed that this extract possessed significant specificity against HCT-15 cells compared to the other cancer cells and no toxicity against normal cells. The results of this study were similar to those reported by [PERSON] et al. [34]. They mentioned that the methanol extract of leaves from _Capsicum annuum_ L. exhibited antiproliferative activity, as determined by an MTT assay, against colorectal cancer cell line (HCT-116), with IC\({}_{50}\) values of 80, 38, and 23% and against breast cancer cell line (MCF-7) with IC\({}_{50}\) values of 78, 37, and 26% at the concentration of 1, 0.5, and 0.25 \(\upmu\)g mL\({}^{-1}\), respectively. Furthermore, the results indicate that the observed bioactivity of each extract could be due to the presence of the different compounds contained in the plant materials as they belong to distinct species [35]. Moreover, according to [PERSON] et al. [33], our results indicated that methanol was the best solvent for extraction, in terms of the cytotoxic properties of the extracts, probably due to the highly polar bioactive compounds extracted [12; 21; 36; 37]. In particularly, in the samples studied, black soil, a loamy sand soil, unlike red ground, a clay loam soil with a medium texture, favored the presence of compounds with intermediates and high polarity, including polyphenols. This was probably associated to the high content of manganese, organic matter, and nitrogen present in the soil. These components have shown an increase in enzyme phenylalanine ammonia-lyase (PAL) activity, which has a significant role in the biosynthesis of polyphenols for plants of the genus _Capsicum_[38]. In this sense, the extract of leaves of _C. chinense_ grown on black soil obtained by maceration with methanol contained vanillin, myricetin, rutin, kaempfer, quercetin + luteolin, hesperidin + diosmin and neohesperidin, as well as chlorogenic acid, coumaric acid, \(p\)-coumaric acid, and cinnamic acid. Their concentrations were 46.20, 461.47, 99.43, 204.07, 506.77, 122.57, 28.53, 308.53, 123.90, 94.17, 125.93 mg 100 g\({}^{-1}\) dry basis, respectively. They are compounds that have exhibited anticancer activity [17]. Nevertheless, the Pearson  
Figure 2: Dose–response of extracts of leaves of _C. chinense_ grown on black soil (LBS), obtained by maceration (n = 3) against cancer cell lines (HeLa, MCF–7, HCT–15, HCT–116, Caov3) and breast normal cell line (184B5). IC\({}_{50}\) HCT–15 = 16.23 \(\pm\) 2.89 \(\upmu\)g mL\({}^{-1}\). correlation coefficient calculated for these polyphenol contents and the cytotoxicity of the samples evaluated in our research showed a very low correlation with values ranging between \(-\)0.29 and 0.21, implying that the polyphenols were not responsible for the cytotoxic activity. On the other hand, [PERSON] et al. [17] indicated that the Soxhlet method extracted more polyphenols from _Capsicum chinense_ by-products than the maceration method.