## 1 Introduction  
In cancer, there is an abnormal proliferation of some cells. It causes nearly one on six deaths worldwide as the principal cause of mortality in advanced cancer patients is multidrug resistance. Moreover, cancer treatments can cause side effects, such as anemia, appetite loss, diarrhea, fatigue, nausea, vomiting, and general pain [1; 2; 3; 4]. Thus, research is focusing on more effective treatments that can contribute to decrease the mortality rate.  
Natural products (NPs) from medicinal plants are of great interest in drug discovery due to their specialized structures and their specific functions. They have been developed through natural evolution and are able to provide unusual features compared to conventional synthetic molecules [5]. NPs such as polyphenols, terpenoids, and coumarins can function like: chemopre drugs, chemotherapeutic drugs, sensitizers, and in reversing chemoresistance [6; 7; 8; 9; 10; 11; 12]. Among the several advantages of drugs derived from NPs, it is possible to include their availability, low cost, and effectiveness [13].  
The diverse plants' genotypes synthesize natural products differentiated by type or quantity. The growing stage, environmental conditions, predation, and diseases are some factors that influence the biosynthesis of secondary metabolites. So, each plant, including each organ of a plant, could be a vast source of molecules for the development of chemotherapy drugs [14]. Nevertheless, there are many unexplored or few explored medicinal plants. One of these is _Capsicum chinense_ Jacq variety Jaguar (commonly known as habanero pepper). This Solanaceae plant is native to the Americas. It was used in traditional medicine by the Aztecs and Mayans [15; 16].  
Nowadays, _C. chinense_ is the main horticultural species commercially exploited in southeastern Mexico, with 358.37 ha cultivated (5049 T) [17] and has a designation of origin in the Yucatan Peninsula according to the Mexican Institute of Industrial Property. These plants are grown in two typical types of soils of Yucatan, \"_K'amakab lu'um_\" or red soils, and \"_Box lu'um_\", or black soils, differentiated by their organic and inorganic composition. The black soil has the highest content of calcium carbonates, organic matter, nitrogen, and phosphorus [18].  
Yearly, around 7.9 million _C. chinense_ plants and 155.3 million peduncles are discarded [17; 19; 20]. However, their leaves and stems are a rich source of bioactive compounds such as polyphenols, terpenoids, and coumarins. Moreover, their extracts have shown pharmacological properties such as antioxidant and anti-inflammatory activities [17; 21; 22]. Nevertheless, there is no research about the anticancer potential of these by-products. In this sense, it is important to evaluate the efficacy of different types of _C. chinense_ by-product extracts as the bioactive compounds' content and the pharmacological activities are highly dependent on the type of extraction and soil where the plants were grown [18; 22; 23].  
Currently, there is an interest in evaluating the bioactivity of extracts obtained using green technologies in comparison with the one obtained with conventional solvent extraction. Green technologies include supercritical fluid extraction, and conventional technologies include maceration [24; 25; 26].  
Based on this background, the aim of the present investigation was to evaluate the antiproliferative activity and modulation effect of the cytotoxicity of extracts obtained from _Capsicum chinense_ by-products of plants grown on black and red soils of Yucatan, Mexico. The by-products were leaves, stems, and peduncles of _C. chinense_ variety Jaguar (Figure 1). Maceration, Soxhlet, and supercritical fluid were the methods used to obtain the extracts [17; 22]. The extracts bioactivities against a panel of human cancer cell lines and a normal human breast cell line were evaluated.  
Figure 1: (**a**) _Capsicum chinense_ (Jaguar variety), (**b**) _C. chinense_ plant grown on red soil, and (**c**) _C. chinense_ plant grown on black soil.