Inflammation, the basis of many kinds of pathological processes, is an automatic defense response of the human body. It is generally triggered by infection, tissue injury, tissue stress and malfunction
[1]. The primary role of inflammation is to eliminate harmful stimuli, prevent further damage, start the healing process and recover the normal functions of injured tissues
[2]. However, host tissue homeostasis will be disarranged or damaged when inflammation is excessive or uncontrolled
[3], which may induce diseases such as acute cytokine storm
[4], rheumatoid arthritis
[5], atherosclerosis
[6] and cancer. In dysregulated inflammatory response, macrophages are hyperactivated to induce oxidant stress and produce more inflammatory media such as reactive oxygen species (ROS), nitric oxide (NO), Prostaglandin E2 (PGE
2), Interleukin-6 (IL-6), Interleukin-1β (IL-1β) and tumor necrosis factor alpha (TNF-α), thereby further aggravating the progression of inflammation
[7][8]. The imbalance of oxidative stress caused by inflammation may also lead to disease exacerbations
[9]. For example, the severity of COVID-19 patients is affected by oxidative stress
[10]. Excessive NO and ROS will destroy lipids, proteins and DNA in cells, and damage the normal function of tissues
[11][12]. In order to reduce the risk of inflammation-related diseases, it is of great significance to suppress dysregulated inflammatory response. Thus, the development of anti-inflammatory agents is still a common concern of many scientists.
In recent years, people have become more aware of the health benefits of natural products derived from fruits, vegetables or other plants, and have shown great interest in developing natural anti-inflammatory agents. Essential oil is a kind of volatile aromatic substance extracted from plants. As a kind of traditional medicine, essential oils have attracted widespread attention because of their potential pharmacological activities including anti-inflammatory, antioxidant
[13], antibacterial
[14] and anticancer potential
[15], etc.
Zingiber striolatum Diels, commonly known as Yang-He in Chinese, belongs to
Zingiber species. As a unique vegetable grown in China, the edible part of
Z. striolatum is the flower. It is widely distributed and predominantly wild but less cultivated
[16].
Z. striolatum possesses high nutritional value because it contains a variety of amino acids, proteins and rich cellulose
[17]. The total amino acid content in
Z. striolatum is 19.83%, of which essential amino acids account for 37.17% of the total amino acids
[18]. A recent study has suggested that the ethanol extract from
Z. striolatum exerted noticeable hypoglycemic activity in vitro
[17]. Tian et al. revealed that the essential oil of
Z. striolatum from the rhizome has weak antioxidant activity but strong antimicrobial and anticancer activities
[19]. They further found that essential oils of
Z. striolatum from flowers, leaves and stems showed significant cytotoxicity against K562, PC-3 and A549 cells
[20]. According to the Compendium of Materia Medica, a famous Chinese medicine classic compiled by Shizhen Li during the 16th century,
Z. striolatum was used for promoting blood circulation, eliminating phlegm, alleviating coughing and relieving swelling and pain, which means it has potential anti-inflammatory activity. However, the regulatory effect of
Z. striolatum on inflammatory response and its molecular mechanism remain to be elucidated.
Therefore, the aim of our study was to assess the anti-inflammatory activity of EOZS and explore its potential molecular mechanism in vitro and in vivo. To understand the material basis of EOZS, we also analyzed their chemical composition from different districts in China by GC–MS.