Alpinia pinnanensis T.L.Wu & S.J.Chen, a species in the Zingiberaceae family, was identified and described from Phu Tho Province, Vietnam. In this study, the essential oil (EO) was extracted from A. pinnanensis rhizomes using hydrodistillation, and its phytochemical constituent was analyzed by gas chromatography-mass spectrometry (GC-MS). The main ingredients identified were β-myrcene (18.72%), farnesol (12.17%), β-linalool (11.91%), and 1,8-cineole (8.82%). The EO exhibited weak antimicrobial activity against Bacillus cereus, Pseudomonas aeruginosa, and Candida albicans with minimum inhibitory concentration (MIC) values ranging from 128 to 256 µg/mL, comparable to positive controls, streptomycin and cycloheximide. Additionally, the EO exhibited cytotoxic effects against HeLa (human cervical carcinoma) and HepG2 (human hepatocellular carcinoma) cell lines, with IC50 values of 8.50 ± 0.29 µg/mL and 7.84 ± 0.15 µg/mL, respectively. This is the first study to report on the phytochemical composition, antimicrobial, and cytotoxic effects of the EO from A. pinnanensis rhizomes.

Alpinia pinnanensis, essential oil, GC-MS, antimicrobial activity, cytotoxicity

Alpinia Roxb. is the largest genus in the Zingiberaceae family, comprising around 500 species (Youn et al. 2024). This genus is primarily distributed across tropical and subtropical regions of Asia and Oceania (Van et al. 2021). Alpinia species are perennial herbaceous plants that typically grow to a height of 2–4 meters, although some species can reach up to 12 meters (Smith 1990; Van et al. 2021). Several species within this genus are of considerable ethnomedicinal and culinary importance in countries such as China, India, Japan, and Vietnam (Zhang et al. 2016; Van et al. 2021). Traditionally, different parts of Alpinia plants have been utilized in the treatment of gastrointestinal ailments, including indigestion, abdominal pain, nausea, and intestinal parasitic infections (Itokawa et al. 1985; Roy and Swargiary 2009). Phytochemical analyses have identified a wide range of bioactive metabolites in Alpinia species, including terpenoids, phenylpropanoids, diarylheptanoids, flavonoids, and lignans (Zhang et al. 2016). Notably, Alpinia is also recognized for its aromatic properties, with various plant parts like fruits, seeds, leaves, rhizomes, roots, shoots, stems, pseudostems, inflorescences, flowers, and petals producing essential oils (EOs) (Van et al. 2021). These EOs are predominantly composed of oxygenated monoterpenes, monoterpene hydrocarbons, and oxygenated sesquiterpenes (Dũng et al. 1994; Hung et al. 2018).

Many of such compounds have been demonstrated to possess significant bioactivities, including anticancer (Chun et al. 1999; Samarghandian et al. 2014), anti-ulcerogenic (Al‐Yahya et al. 1990), antimicrobial (Niyomkam et al. 2010; Rao et al. 2010), hypoglycemic (Rajasekar et al. 2014), anti-nausea (Shin et al. 2002; Yang et al. 2002), cardioprotective (Chang et al. 2013), neuroprotective (Li et al. 2013; Shi et al. 2015), and anxiolytic activities (De Sousa et al. 2015).

Alpinia pinnanensis T.L.Wu & S.J.Chen, a herbaceous plant reaching approximately 1.5 meters in height, features lanceolate leaves with distinctive golden trichomes (Huong et al. 2017). Previous phytochemical investigations of this species have led to the identification of diarylheptanoids, flavonoids, and triterpenoids (Giang et al. 2005). EOs have also been extracted from various parts of A. pinnanensis, including its leaves, stems, root bark, and fruits (Huong et al. 2017). However, the chemical composition of the EO derived specifically from the rhizomes of A. pinnanensis has not been reported. This study was therefore conducted to analyze the chemical constituents of EO from A. pinnanensis rhizomes and to assess its in vitro antimicrobial and cytotoxic activities.

The phytochemical constituent of the rhizome EO was analyzed using GC-MS, identifying a total of 55 volatile components, which accounted for 96.13% of the total oil content (Fig. 1, Table 1). The primary chemical classes in the rhizome oil included monoterpene hydrocarbons (33.02%), oxygenated monoterpenes (31.36%), and oxygenated sesquiterpenes (23.13%). The major constituents (≥ 5%) were β-myrcene (18.72%), farnesol (12.17%), β-linalool (11.91%), and 1,8-cineole (8.82%). Additionally, several prominent compounds (≥ 2%) were identified, including camphene (3.46%), α-phellandrene (3.09%), α-pinene (2.63%), fenchyl acetate (2.53%), camphor (2.39%), and α-limonene (2.22%).

Figure 1. 

The GC chromatogram of A. pinnanensis rhizome essential oil.

Comparatively, EOs derived from other parts of A. pinnanensis exhibited distinct chemical profiles. The leaf oil was dominated by 1,8-cineole (20.5%), 4-phenyl-2-butanol (19.5%), and α-phellandrene (10.8%). The stem oil primarily contained 1,8-cineole (10.0%), β-elemene (8.7%), α-gurjunene (7.6%), β-pinene (7.3%), and (E,E)-farnesol (7.2%). The root oil featured (E,E)-farnesol (8.4%), α-gurjunene (6.2%), camphene (5.6%), fenchyl acetate (5.4%), linalool (4.6%), and β-pinene (4.6%). In contrast, the fruit oil was characterized by α-cadinol (18.1%) and β-caryophyllene (11.4%), along with (E,E)-farnesol (6.3%), β-pinene (6.1%), β-elemene (5.6%), and α-pinene (5.1%) (Huong et al. 2017). This analysis highlights the diversity of chemical compositions in EOs from different parts of A. pinnanensis, with each exhibiting a unique profile of major and minor constituents.

The oil sample was then evaluated for its antimicrobial activities against several bacterial and fungal strains using the broth microdilution method, with streptomycin and cycloheximide as positive controls (Table 2). For bacterial strains, the EO demonstrated variable inhibitory effects. No antimicrobial activity was observed against E. faecalis, S. aureus, E. coli, and S. enterica, as evidenced by the lack of inhibition at the tested concentrations. In contrast, B. cereus showed a MIC of 128 µg/mL, indicating moderate antibacterial activity. P. aeruginosa exhibited MIC values of 256 µg/mL, suggesting relatively weak antibacterial effects of the EO. Regarding antifungal activity, the EO exhibited weak inhibition of C. albicans, with a MIC of 256 µg/mL, indicating a limited antifungal potential. The relatively low antimicrobial activity of EO from A. pinnanensis rhizomes can be attributed to its chemical composition. Previous studies have indicated that EOs rich in aldehydes or phenols exhibit the strongest antibacterial activity, followed by those containing terpene alcohols (Bassolé and Juliani 2012; Hamad et al. 2016). In contrast, EOs containing ketones, esters, or acetates generally display weaker antimicrobial effects, while oils primarily composed of terpene hydrocarbons are often inactive (Kalemba and Kunicka 2003; Bassolé and Juliani 2012; Hamad et al. 2016; Lis et al. 2017). The EO from A. pinnanensis rhizomes contains a high proportion of terpene hydrocarbons and terpene alcohols, both of which exhibit relatively low antimicrobial activity. This explains the observed weak antibacterial effects of the oil against the tested bacterial strains.

The cytotoxic effects of the EO of A. pinnanensis rhizomes on HepG2 and HeLa cancer cell lines were evaluated. The results in Table 3 demonstrate that this EO exhibited activity on all evaluated cell lines. Specifically, the IC₅₀ values of the EO of A. pinnanensis rhizomes for HepG2 and HeLa cell lines were 7.84 ± 0.15 and 8.50 ± 0.29 μg/mL, respectively. The cytotoxic effects of this EO are likely attributed to its major components. Previous studies have shown that β-myrcene inhibits the invasion of metastatic MDA-MB-231 human breast cancer cells by suppressing TNFα-mediated NF-κB activation, achieved through the inhibition of IKK, which subsequently downregulates MMP-9 expression (Lee et al. 2015). Furthermore, β-myrcene demonstrated significant antiproliferative activity against A549 lung cancer cells by activating apoptosis via mitochondria-mediated cell death signaling and inducing oxidative stress (Bai and Tang 2020). At a concentration of 50 nM, β-myrcene also inhibited HeLa cell proliferation by increasing the cell doubling time and significantly altering cell motility, which suggests cell cycle arrest and reduced invasion capacity (Pincigher et al. 2023). Similarly, farnesol has been recognized for its anti-neoplastic effects in various cancers, including prostate, breast, lung, and pancreatic cancers and multiple myeloma, by inhibiting cell proliferation in vitro and suppressing tumor growth in vivo (Jung et al. 2018). β-linalool, another major component of A. pinnanensis rhizome EO, also exhibited cytotoxic effects in human breast cancer cells (MCF-7, MDA-MB-231, T-47D, A549) (Chang and Shen 2014; Rodenak-Kladniew et al. 2020; Elbe et al. 2022), human hematopoietic malignancies (Kasumi-1, HL-60, Molt-4, H-9), lymphoma (Raji) (Gu et al. 2010), human oral cancer cells (OECM 1) (Pan and Zhang 2019), human colon cancer cells (SW 620) (Chang and Shen 2014), and human hepatocellular carcinoma (HepG2) (Chang and Shen 2014). Lastly, 1,8-cineole exhibited antiproliferative effects on human colon cancer cell lines (HCT116 and RKO) (Murata et al. 2013) and human breast cancer cells (A549) (Rodenak-Kladniew et al. 2020).

This study presents the first comprehensive analysis of the chemical composition, antimicrobial properties, and cytotoxic activity of EO extracted from the rhizomes of Alpinia pinnanensis collected in Phu Tho Province, Vietnam. The chemical profile of the EO was extensively characterized, revealing weak antimicrobial activity. However, the oil exhibited notable cytotoxic effects against HeLa and HepG2 cancer cell lines. These results provide valuable insights into the potential therapeutic applications of A. pinnanensis EO.

Conflict of interest

The authors have declared that no competing interests exist.

Ethical statements

The authors declared that no clinical trials were used in the present study.

The authors declared that no experiments on humans or human tissues were performed for the present study.

The authors declared that no informed consent was obtained from the humans, donors or donors’ representatives participating in the study.

The authors declared that no experiments on animals were performed for the present study.

The authors declared that no commercially available immortalised human and animal cell lines were used in the present study.

Funding

No funding was reported.

Author contributions

Conceptualization, N.T.T., T.V.C., L.D.G., H.T-T., and V.T.N.; methodology, V.T.N., N.T.V. and L.D.G..; software, H.T-T and T.V.C; investigation, N.T.T., L.D.G., H.T-T., L.T.G.A., and N.T.V., writingoriginal-draft preparation, V.T.N., N.T.T., H.T-T.; writingreview and editing N.T.T., H.T-T., and V.T.N.; visualization, N.T.T., H.T-T., and L.T.G.A.; supervision, H.T-T and V.T.N.

Author ORCIDs

Nguyen Thanh Triet https://orcid.org/0000-0001-6710-2448

Tran Van Chen https://orcid.org/0000-0003-1430-231X

Le Duc Giang https://orcid.org/0000-0002-3269-9915

Hieu Tran-Trung https://orcid.org/0000-0002-0639-4261

Nguyen Thi Giang An https://orcid.org/0000-0003-3243-1422

Nguyen Van Thu https://orcid.org/0000-0002-4836-3359

Data availability

All of the data that support the findings of this study are available in the main text.