## 1 Introduction  
Plants have been regarded as a useful source of natural medicines for curing diverse human diseases since ancient times [1]. Plants are rich in phytochemicals that are useful as natural medicines and provide health benefits. Nowadays, natural medicines are more popular because of their beneficial effects and lower prices, compared to high-cost synthetic drug agents, and are widely used for the prevention and treatment of many diseases [2]. Hundreds of plant species have been widely used as natural herbal materials in many industries, such as pharmaceuticals, cosmetics, and nutraceuticals [3].  
_Gynostemma pentaphyllum_ (Thunb.) Makino, known as Jiagoulan in China, is a dicotyledonous and perennial plant belonging to the Cucurbitaceae family, which includes cucumber, pumpkin, and melon [4]. _G. pentaphyllum_ (GP) has a dioecious reproductive system, with distinct individual organisms that produce male or female gametes. GP is an herbaceous vine plant distributed in the United States and Asian countries, such as China, Korea, Japan, Malaysia, and India, and has been traditionally consumed as a food and tea in many countries [5].  
Numerous studies have indicated that GP extracts have many beneficial effects, such as antioxidant [6, 7], anticancer [8], cholesterol reduction [9], hypoglycemic [10, 11], and immunoprecipitation effects [12]. GP extract contains a diverse group of substances. Ofthese, saponins, also known as spprenosides, are the main constituents of GP extracts [13]. Gypenosides from GP extracts are similar to those from ginseng plant species [14; 15], and both GP and ginseng extracts have anti-diabetic effects.  
Secondary metabolites are the phytochemical components of various pharmaceutical plants [16]. The production of secondary metabolites in plants is often regulated by environmental conditions, such as biotic and abiotic stresses, to maintain plant physiology.  
Recently, the development of plant tissue culture techniques and large-scale plant cell culture using bioreactors has facilitated the massive production of plant components, such as secondary metabolites from diverse plants [17]. Plant cell culture techniques are independent of climate and geographical region, and a small amount of initial plant material can lead to large-scale production within a short amount of time using a bioreactor [18]. Furthermore, the quality of the plant material in the bioreactors is uniform, enabling easier quality management.  
The composition of plant extracts can vary according to the extraction method [19]. The amount of active ingredients present in plant materials is usually very low. Thus, effective and appropriate methods should be selected to extract the target bioactive natural compounds.  
With the rapid development of high-throughput sequencing, RNA sequencing has become a powerful tool for the gene expression analysis of transcriptomes. Moreover, several previous studies have demonstrated that RNA sequencing-based transcriptome approaches are efficient in identifying differentially expressed genes (DEGs) associated with several plant extracts, such as _Leontopodium alipinum_ (Edelweiss) [20], _Camelia japonica_[21], _Isatis tinctoria_ L. [22], _Ricinus communis_ L. [23], and metabolites such as porphya-334 [24], kaempferol [25], Angelica polysaccharide [26], and plant-derived exosomes [27].  
In this study, we established a method for the large-scale production of GP cells using plant tissue culture techniques combined with bioreactors. Furthermore, we conducted transcriptome analyses of HaCaT cells in response to three different GP extracts to identify the key genes related to the effects of GP extracts.