1. Antitussive, Expectorant and Anti-Asthmatic Activities
Antitussive, expectorant, and anti-asthmatic activities of
S. grosvenorii have been widely reported. Aqueous extract of
S. grosvenorii (SGA) significantly inhibited coughs induced by concentrated ammonia or sulfur dioxide (SO
2) in mice, as well as increasing the secretion of phenolsulfonphthalein in mice and the excretion of sputum in rats, resulting in a visible expectorant activity
[1]. Sung
[2] et al. investigated the anti-asthmatic activity of
S. grosvenorii residual extract (SGRE) against ovalbumin (OVA)-induced asthma in mice. The research showed that oral administration of SGRE significantly reduced Th2 cytokines (IL-4, IL-5, and IL-13) and increased the Th1cytokine IFN-γ in the BAL fluid and supernatant of splenocyte cultures. SGRE decreased the OVA-induced increase of IL-13, TARC, MUC5AC, TNF-a, and IL-17 expression in the lung. Mogrosides could inhibit ammoniainduced cough in mice and promote mucus movement in the esophagus of frogs. According to the research, mogrosides (50, 100, and 200 mg/kg) enhanced sputum secretion in mice in a dose-dependent manner, and topical application of mogrosides enhanced ciliary cell motility in the frog respiratory tract. The results from intragastric administration showed that the anti-cough activity achieved by mogrosides positively correlated with dose, at a minimum inhibitory concentration of 80 mg/kg
[3].
2. Antioxidant
Mogrosides have specific scavenging activities on hydroxyl and superoxide anion free radicals, which could reduce the occurrence of erythrocyte haemolysis, inhibit malondialdehyde production in liver mitochondria and oxidative haemolysis in rat erythrocytes, inhibit lipid peroxidation in rat liver tissues, and protect liver tissues from peroxidative damage caused by ferrous ions and hydrogen peroxide. A bioactivity experiment on
S. grosvenorii polysaccharide (SGP) (molecular weight 1.93 × 103 kDa), has indicated
[4] promising antioxidant properties in vitro, particularly in scavenging DPPH radicals. Among H
2O
2 oxidation-damaged PC12 cells, SGP reduced ROS and the percentage of apoptotic and necrotic cells in a dose-dependent way. Clearly, mogroside V (
4) and 11-oxomogroside V (
6) exhibited inhibitory activities on reactive oxygen species (O
2−, H
2O
2 and -OH) and DNA oxidative damage. As compared with 11-oxo-mogroside V (
6), mogroside V (
4) is more active in the scavenging of -OH, and 11-oxo-mogroside V (
6) is more active in the scavenging of O
2− and H
2O
2, 11-oxo-mogroside V (
6) also inhibited OH-induced DNA damage
[5]. Meanwhile, mogroside V (
4) promotes the anti-oxidative stress capacity of skin fibroblasts by modulating the scavenging of free radicals with antioxidant enzymes, which could be used to prevent skin aging or lesions. In MSF treated with H
2O
2, mogrosides V (
4) reduced ROS levels and MDA content, together with an increase in superoxide dismutase (SOD), glutathione peroxide (GSH-Px), and catalase (CAT) activities
[6]. Furthermore, mogroside extracts (MGE) inhibited BSA glycation, as evidenced by the formation of fluorescent advanced glycation end products (AGEs) at 500 μg/ml with lower levels of protein carbonate and Ne-(carboxymethyl) lysine. MGE may be a potential anti-glycation treatment for diabetic problems by inhibiting protein glycation and sugar oxidation
[7]. According to studies
[8], mogroside IIIE (
5) could decrease the levels of inflammatory cytokines and oxidative stress-related biomarkers. Furthermore, with intervention by mogroside IIIE (
5), HG-induced apoptosis in podocytes was inhibited. Through activation of AMPK-SIRT1 signaling, mogroside IIIE (
5) alleviates HG-induced inflammation and oxidative stress in podocytes. Ethanol extract of
S. grosvenorii (SGE) significantly increased load swimming duration to exhaustion in mice. It could potentially suppress the reduction of HB and LD production during exercise and promote the HB synthesis and LD clearance in the recovery period, thus maintaining a high level of exercise capacity. The active ingredients could effectively promote the increase of SOD and GSH-Px activities in myocardial tissues of mice, and significantly inhibit the increase of MDA. Moreover, they can timely scavenge the excess free radicals produced during exercise during the recovery period and effectively prevent or resist lipid peroxidation in the body, which has obvious protective effects on the heart and other tissue damage caused by exercise. It has a positive effect on delaying the incidence and development of exercise fatigue
[9].
3. Antidiabetic and Antihyperlipidemic Activies
The hypoglycemic activity of cucurbitanes has been discovered, yet the underlying mechanism has not yet been discovered. Four cucurbitacins isolated from bitter melon (
Momordica charantia L.) exhibit several beneficial biological activities against diabetes and obesity, whose hypoglycemic activity is associated with the enhanced effects of AMPK, a key pathway mediating glucose uptake and fatty acid oxidation, causing a decrease in fasting glucose and improving glucose tolerance in normal animals, diabetic animals, and humans
[10]. Mogrol (
1), 3-hydroxymogrol (
2) and 3-hydroxy-25-dehydroxy-24-oxo-mogrol (
7) are efficient AMPK activators in the HepG2 cell line. Both mogrol (
1) and 3-hydroxymogrol (
2) play a role in the hypoglycemic and anti-hyperlipid activities of this plant in vivo
[11]. The MGE-fed diabetic mice induced a marked decrease in fasting plasma glucose (FPG), glucosylated serum protein (GSP), serum insulin and HOMA-IR in a dose-dependent manner, whereas insulin sensitivity, glucose, and insulin tolerance increased significantly. Lipid accumulation and adipose deposition improved and recovered to nearly normal at high doses
[12]. Activation of AMPK signaling is dose-dependent.Accordingly, mRNA levels of hepatic glycogenicity and lipogenicity genes are down-regulated, whereas lipoxidation-related genes are up-regulated.
4. Anti-Inflammatory
S. grosvenorii residual extract (NHGR) is an inexpensive raw material. Sung
[13] et al. investigated NHGR anti-allergic activity using in vivo models of atopic dermatitis (AD) characterized by mite allergens, alongside with its effects on keratocytes and immune cells. Treatment with NHGR in vitro restored the effects of pro-inflammatory cytokines on the increased filaggrin expression and reduced Dermatophagoides farinae mite antigen extract (DfE) induced phosphorylation of ERK, JNK, and p38, resulting in anti-inflammatory activity. Additionally, SGA enhanced monocyte phagocytosis in hydrocortisone injured mice and enhanced immune function
[14]. Mogroside IIIE (
5) is a compound with excellent anti-inflammatory properties, which has an improved effect on glucose metabolism, insulin resistance, and reproductive outcomes in gestational diabetes mellitus (GDM) mice. As a complication of the gestational disease, GDM clinically affects the health of mothers and infants. The treatment reduced inflammatory factor expression and alleviated GDM symptoms by enhancing AMPK activation, inhibiting HDAC4 expression, and decreasing G6Pase production
[15]. Similarly, mogroside IIIE (
5) inhibited lung fibroblast collagen production by blocking the direct differentiation of lung pericytes and resident fibroblasts induced by TGF-β or LPS. These findings suggest that mogroside IIIE (
5) is an effective pulmonary fibrosis inhibitor. In vitro and in vivo models have been utilized to demonstrate that mogroside IIIE (
5) significantly eliminates fibrosis in a mouse model of bleomycin-induced pulmonary fibrosis
[16]. Acute lung injury (ALI) has a high mortality rate, but there is no effective treatment available. Molecular studies have shown that mogroside IIIE (
5) increases AMPK phosphorylation while inhibiting toll-like receptor 4 (TLR4) overexpression. In addition, compound C (a pharmacological AMPK inhibitor) reversed the anti-inflammatory activity of mogroside IIIE (
5) in LPS-induced ALI mice
[17]. Mogroside IIIE (
5) has the greatest inhibitory activity on NO (an important inflammatory factor) release from LPS-induced RAW264.7 cells, eliminating pulmonary fibrosis and demonstrating a decrease in myeloperoxidase (MPO) activity, collagen deposition and pathology scores. The expression of several fibrosis markers, such as liver fibrosis, has been significantly inhibited
[18]. The anti-fibrotic activity of mogroside IIIE (
5) may be due to downregulation of TLR4 signaling from fibroblasts as a result of its inhibiting activation by fibroblasts and deposition of ECM
[19]. In the same way, TLR is the main innate immune factor activated by LPS. In the last few years, some evidence has shown that TLR4 activation binds to adaptor protein MyD88 and activates NF-κB
[20]. Song
[21] et al. provided evidence that mogroside V (
4) has anti-asthmatic activity against OVA-induced asthma in mice. Effectively, mogroside V (
4) reduced OVA-induced airway hyperresponsiveness and the number of inflammatory cells in bronchoalveolar lavage fluid (BALF). On histological examination, mogroside V (
4) reduced IgE and IgG production and rectified the balance between Th1 and Th2 cytokines in asthmatic mice, which could be beneficial to potential protective mechanisms against OVA-induced asthma. Several lines of evidence suggest that microglia play a key role in the brain of AD patients and are critical in the pathogenesis of the disease, as activation of microglia promotes the release of pro-inflammatory factors that largely influence AD pathogenesis
[22]. In a recent study, mogrosides V (
4) has been proven to be active against LPS-induced neuroinflammation in microglia, significantly reducing the expression of pro-inflammatory proteins
[23]. Simultaneously, mogroside IIE (
3) inhibited trypsin and cathepsin B activity induced by cerulein and LPS in pancreatic islet cells AR42J and primary acinar (AP) cells in a dose- and time-dependent manner. Also, mogroside IIE (
3) lower IL-9 levels in AP mice and reverse the inhibition of cytoplasmic calcium and the regulation of autophagy mediated by it
[24].
5. Liver Protection
In THP-1 cells, high-purity mogroside V (
4) suppresses reactive oxygen species generation and increases the expression of sequestosome-1 (SQSTM1, p62). Thus, mogroside could help treat obesity and non-alcoholic fatty liver disease (NAFLD) by strengthening fat metabolism and antioxidant function
[25]. Mogroside V (
4) also significantly ameliorate hepatic steatosis in mice fed a high-fat diet. Likewise, in free fatty acid (FFA) cultured LO2 cells, mogroside V (
4) down-regulated de novo lipogenesis and up-regulated steatolysis and fatty acid oxidation, thereby reducing fat accumulation, improving hepatic steatosis induced by HFD, and alleviating the imbalance between lipid acquisition and lipid clearance
[26].
6. Antibacterial and Antiviral Activities
General research has shown that flavonoids with fewer sugar groups have better antibacterial activity
[27]. All the flavonoids have an inhibitory activity on Gram-positive bacteria but no inhibitory activity on Gram-negative bacteria. The MIC values of grosvenorine (
10) and its four metabolites against Gram-positive bacteria were all less than 70 mg/mL, indicating that grosvenorine (
10) and its four metabolites had antibacterial activity against gram-positive bacteria, showing the best antibacterial activity with kaempferol (
9). MSSA are sensitive microorganisms. Afzelin (
11), a flavonoid glycoside, has shown significant inhibitory activity against MSSA and MRSA, as well as Enterococcus. It is well known that flavonoids are strongly hydrophobic and readily penetrate bacterial phospholipid membranes to exert intracellular inhibitory activity
[28]. In recent studies, β-amyrin (
8), ergosterol peroxide (
14), aloe-emodin (
12), aloe-emodin acetate (
13), and 4-hydroxybenzoic acid (
15), all isolated from the leaves of
S. grosvenorii. It has been demonstrated in vitro that they inhibit the growth activities of oral bacterial species, such as
Streptococcus mutans,
Actinobacillus,
Clostridium sclerotiorum, and
Candida albicans. Among all the active compounds, aloe-emodin (
16) had the highest effects against all the tested bacteria and yeast, with MIC values ranging from 1.22 to 12.20 mg/mL
[29]. As for this, researchers have discovered that ethanol-eluting via 50%, 70%, and 95% parts of
S. grosvenorii has different inhibition rates against
Escherichia coli bacterial biofilms (BBF), respectively. Therefore, the ethanol-extracted fraction of
S. grosvenorii showed significantly better antibacterial activity than the water-extracted fraction
[30]. The borderless transmission of coronavirus remains uncontrolled globally. The undetected severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant reduces the therapeutic efficacy of vaccines against coronavirus disease 2019 (COVID-19). Clinical observations suggest that tumor cases are highly infected with coronavirus, possibly due to immunologic injury, causing a higher COVID-19-related death toll
[31][32]. Based on network pharmacology analysis, the current research identified 24 candidate targets and 10 core targets for mogroside V (
4) for treating COVID-19
[33]. Mogroside V may treat COVID-19 by targeting JUN, IL2, HSP90AA1, AR, PRKCB, VEGF, TLR9, TLR7, STAT3, and PRKCA. Further analysis using molecular docking suggested potent binding scores between mogroside V (
4) and the core target protein in COVID-19. VEGF, a core protein docked well with mogroside V (
4), has been identified as a pharmacological target in mogroside V (
4) treatment of COVID-19. Clinically, VEGF may induce vascular impairment in gastrointestinal cells infected with SARSCoV-2
[34].
7. Miscellaneous Activities
Mogroside V (
4) has comprehensive anti-cancer activities. The natural sweet compound mogroside V (
4) could inhibit the proliferation and survival of pancreatic cancer cells by focusing on multiple biological targets. In both in vitro and in vivo models of pancreatic cancer, mogroside V (
4) has tumor growth inhibitory activity by promoting apoptosis and cell cycle arrest in pancreatic cancer cells (PANC-1 cells), possibly through modulation of the STAT3 signalling pathway, promoting cell proliferation (CCND1, CCNE1 and CDK2), while also upregulating cell cycle inhibitors (CDKN1A and CDKN1B)
[35]. Mogroside V (
4) inhibited hypoglycemic-induced lung cancer cell migration and invasion by reversing EMT and disrupting the cytoskeleton. In lung cancer cells cultured under hypoglycemic conditions, the metastatic efficiency of mogroside V (
4) was compared with normoglycemia, which reversed hyperglycemia-induced invasion and migration by upregulating E-Cadherin expression and downregulating N-Cadherin, Vimentin, and Snail expression. Meanwhile, the expression levels of Rho A, Rac1, Cdc42 and p-PAK1 protein were decreased in a dose-dependent manner
[36]. After injection of Aβ1-42, mice showed a distinct increase in escape latency and a distinct decrease in the number of times they crossed the target and time spent in the target quadrant. Mogrol (
1) could significantly alleviate memory impairment caused by Aβ1-42, inhibit microglia overactivation and prevent hippocampus apoptosis, downregulate the high expression of IL1β, IL-6, NF-kB p65, TNF-a induced by Aβ1–42, reduce the neuroinflammation
[37]. Likewise, this plant plays a role in anti-aging. Rats fed with
S. grosvenorii showed a slower ageing process. The experimental group maintained a stationary LSK state, decreased ROS level, augmented hematopoietic stem cells, and reduced the number of β-gal positive cells associated with aging, thus lowering the expression of aging-related proteins and slowing the aging process in rats
[38].
8. Summary of Pharmacologic Activities
In conclusion, S. grosvenorii has a wide range of pharmacological activities (Table 1). Modern pharmaceutical research mainly focuses on extracts and chemical components, indicating the prospects of S. grosvenorii in the treatment of such diseases.
Table 1. Pharmacological activities of S. grosvenorii.
Activities |
Detail |
Extracts/Compounds |
Concentration/Dose |
In Vivo/In Vitro |
Ref. |
Antitussive, expectorant and anti-asthmatic activities |
increased the secretion of phenolsulfonphthalein in mice and the excretion of sputum in rats |
SGA |
4000 and 8000 mg/kg |
in vivo |
[1] |
reduced Th2 cytokines (IL-4, IL-5, and IL-13) and increased the Th1cytokine IFN-γ |
SGRE |
200 mg/kg |
in vivo |
[2] |
enhanced sputum secretion in mice and ciliary cell motility in the frog respiratory tract |
mogrosides |
50, 100, and 200 mg/kg |
in vivo |
[3] |
Antioxidant |
decrease ROS in oxide injury PC12 cells and decrease apoptotic and necrotic cells |
SGP |
0.5, 1.0, 1.5, 2.0 mg/mL |
in vitro |
[4] |
reduced ROS levels and MDA content, increase SOD, GSH-Px and CAT activities |
mogroside V |
30, 60, and 90 µg/mL |
in vitro |
[6] |
scavenging of -OH |
mogroside V |
PC12 cells EC50 = 48.44 μg/mL |
in vitro |
[5] |
scavenging of O2 and H2O2, inhibited -OH induced DNA damage |
11-oxomogroside V |
PC12 cells EC50 = 4.79 μg/mL, EC50 = 16.52 μg/mL, EC50 = 3.09 μg/mL |
in vitro |
[5] |
inhibited BSA glycation |
MGE |
500 μg/mL |
in vitro |
[7] |
decrease the levels of inflammatory cytokines and oxidative stress-related biomarkers |
mogroside IIIE |
MPC-5 cells 1, 10, and 50 μM |
in vitro |
[8] |
inhibited the reduction of HB and LD and inhibited the increase of MDA, promoted the synthesis of HB and the clearance of LD |
SGE |
1500 mg/kg |
in vivo |
[9] |
Hypoglycemic |
increase AMPK phosphorylation |
mogrol |
HepG2 cell line 1, 10, and 20 μM |
in vivo |
[11] |
increase AMPK phosphorylation |
3-hydroxymogrol |
HepG2 cell line 1, 10, and 20 μM |
in vivo |
[11] |
increase AMPK phosphorylation |
3-hydroxy-25-dehydroxy-24-oxo-mogrol |
HepG2 cell line 4 μM |
in vivo |
[11] |
downregulated mRNA levels of hepatic gluconeogenic and lipogenic genes, upregulated fat oxidation-associated genes |
MGE |
300 mg/kg |
in vivo |
[12] |
Immunology and anti-inflammatory |
increased filaggrin expression and reduced DfE induced phosphorylation of ERK, JNK and p38 |
NHGR |
200 or 400 mg/kg |
in vivo |
[13] |
enhanced monocyte phagocytosis in hydrocortisone injured |
SGA |
2500 and 5000 mg/kg |
in vivo |
[14] |
decreased expression of IL-1b, IL-6, and TNF-a |
mogroside IIIE |
GDM model 20.0 mg/kg |
in vivo |
[15] |
inhibited LPS-induced inflammatory |
mogroside IIIE |
RAW264.7 cells 10 μM |
in vitro |
[15] |
inhibited LPS-induced inflammatory |
mogroside IIIE |
RAW264.7 cells 1, 10 or 50 μM |
in vitro |
[17] |
reduced the OVA-induced activation of NF-κB |
mogroside V |
2, 5, and 10 mg/kg |
in vivo |
[21] |
inhibited LPS-induced inflammatory |
mogroside V |
BV-2 cells 6.25, 12.5 and 25 μM |
in vitro |
[23] |
inhibited the IL-9/IL-9R/calcium overload/cathepsin B activation/trypsinogen activation pathway |
mogroside IIE |
AR42J cells 5, 10 and 20 μM |
in vitro |
[24] |
Liver protection |
inhibited reactive oxygen species production and upregulated sequestosome-1 (SQSTM1, p62) expression |
mogroside V |
200, 400, and 800 mg/kg |
in vivo |
[25] |
activated AMPK ameliorates HFD-induced hepatic steatosis |
mogroside V |
LO2 cells 15, 30, 60, and 120 μM |
in vitro |
[26] |
Antibacterial and anti-viral |
inhibitory effects against gram-positive bacteria |
grosvenorine |
MIC less than 70 μg/mL |
in vitro |
[27] |
inhibitory effects against gram-positive bacteria |
kaempferitrin |
MIC less than 70 μg/mL |
in vitro |
[27] |
inhibitory effects against gram-positive bacteria and MSSA |
kaempferol |
MIC less than 70 μg/mL |
in vitro |
[27] |
inhibitory effects against MSSA and MRSA |
afzelin |
MIC less than 70 μg/mL |
in vitro |
[27] |
inhibitory effects against Streptococcus mutans, Actinobacillus actinobacillus, Clostridium sclerotiorum, and Candida albicans |
β-amyrin |
MIC = 48.80, >100, 48.40, and >100 μg/mL |
in vitro |
[29] |
inhibitory effects against Streptococcus mutans, Actinobacillus actinobacillus, Clostridium sclerotiorum, and Candida albicans |
ergosterol peroxide |
MIC = 4.88, 48.80, 48.80, and 12.20 μg/mL |
in vitro |
[29] |
inhibitory effects against Streptococcus mutans, Actinobacillus actinobacillus, Clostridium sclerotiorum, and Candida albicans |
aloe-emodin |
MIC = 1.22, 6.10, 12.20, and 6.10 μg/mL |
in vitro |
[29] |
inhibitory effects against Streptococcus mutans, Actinobacillus actinobacillus, Clostridium sclerotiorum, and Candida albicans |
aloe-emodin acetate |
MIC = 6.10, 12.20, >100, and 6.10 μg/mL |
in vitro |
[29] |
inhibitory effects against Streptococcus mutans, Actinobacillus actinobacillus, Clostridium sclerotiorum, and Candida albicans |
4-hydroxybenzoic acid |
MIC = 12.20, >100, 12.20, and 12.20 μg/mL |
in vitro |
[29] |
inhibitory effects against Escherichia coli bacterial biofilms |
different ethanol-eluting parts of S. grosvenorii |
MIC = 55.58, 78.32, and 87.62% |
in vitro |
[28] |
regulation of VEGF |
mogroside V |
- |
in vitro |
[33] |
Miscellaneous activities |
inhibited expression of the STAT3 pathway |
mogroside V |
PANC-1 cells 10, 100, and 250 μM |
in vivo and in vitro |
[35] |
inhibited expression levels of Rho A, Rac1, Cdc42 and p-PAK1 |
mogroside V |
A549 and H1299 cells 0–50 μM |
in vitro |
[36] |
inhibited expression of IL1β, IL-6, NF-κB p65, TNF-a induced by Aβ1–42 |
mogrol |
20, 40, 80 mg/kg |
in vivo |
[37] |
decrease the intercellular levels of ROS |
extract of S. grosvenorii |
200 mg/kg |
in vivo |
[38] |