Antioxidant activity and ultrastructural changes in gastric cancer cell lines induced by Northeastern Thai edible folk plant extracts

Comparative Analysis of Volatile Compounds and Biochemical Activity of Curcuma xanthorrhiza Roxb. Essential Oil Extracted from Distinct Shaded Plants

The application of shade during plants' growth significantly alters the biochemical compounds of the essential oil (EO). We aimed to analyze the effect of shade on the volatile compounds and biochemical activities of EO extracted from Curcuma xanthorrhiza Roxb. (C. xanthorrhiza) plants. Four shading conditions were applied: no shading (S0), 25% (S25), 50% (S50), and 75% shade (S75). The volatile compounds of EO extracted from each shaded plant were analyzed by gas chromatography-mass spectrometry. The antioxidant, antibacterial, and antiproliferative activities of EO were also investigated. We found that shade application significantly reduced the C. xanthorrhiza EO yield but increased its aroma and bioactive compound concentration. α-curcumene, xanthorrhizol, α-cedrene, epicurzerenone, and germacrone were found in EO extracted from all conditions. However, β-bisabolol, curzerene, curcuphenol, and γ-himachalene were only detected in the EO of S75 plants. The EO of the shaded plants also showed higher antioxidant activity as compared to unshaded ones. In addition, the EO extracted from S75 exerted higher antiproliferative activity on HeLa cells as compared to S0. The EO extracted from S0 and S25 showed higher antibacterial activity against Gram-positive bacteria than kanamycin. Our results suggest that shade applications alter the composition of the extractable volatile compounds in C. xanthorrhiza, which may result in beneficial changes in the biochemical activity of the EO.

Overview of the Justicia Genus: Insights into Its Chemical Diversity and Biological Potential

The genus Justicia has more than 600 species distributed in both hemispheres, in the tropics and temperate regions, and it is used in the treatment of numerous pathologies. This study presents a review of the biological activities of plant extracts and isolated chemical constituents of Justicia (ACANTHACEAE), identified in the period from May 2011 to August 2022. We analyzed over 176 articles with various biological activities and chemical compound descriptions present in the 29 species of Justicia. These have a variety of applications, such as antioxidant and antimicrobial, with alkaloids and flavonoids (e.g., naringenin) the most frequently identified secondary metabolites. The most observed species were Justicia gendarussa Burm., Justicia procumbens L., Justicia adhatoda L., Justicia spicigera Schltdl, and Justicia pectoralis Jacq. The frontier molecular orbitals carried out using density functional theory (M062X and basis set 6-311++G(d,p) indicate reactive sites for naringenin compound and a chemical reaction on phytomedicine activity. The energy gap (206.99 kcal/mol) and dimer solid state packing point to chemical stability. Due to the wide variety of pharmacological uses of these species, this review points toward the development of new phytomedicines.

Glochidion littorale Leaf Extract Exhibits Neuroprotective Effects in Caenorhabditis elegans via DAF-16 Activation

A number of plants used in folk medicine in Thailand and Eastern Asia are attracting interest due to the high bioactivities of their extracts. The aim of this study was to screen the edible leaf extracts of 20 plants found in Thailand and investigate the potential neuroprotective effects of the most bioactive sample. The total phenol and flavonoid content and 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity were determined for all 20 leaf extracts. Based on these assays, Glochidion littorale leaf extract (GLE), which showed a high value in all tested parameters, was used in further experiments to evaluate its effects on neurodegeneration in Caenorhabditis elegans. GLE treatment ameliorated H₂O₂-induced oxidative stress by attenuating the accumulation of reactive oxygen species and protected the worms against 1-methyl-4-phenylpyridinium-induced neurodegeneration. The neuroprotective effects observed may be associated with the activation of the transcription factor DAF-16. The characterization of this extract by LC-MS identified several phenolic compounds, including myricetin, coumestrin, chlorogenic acid, and hesperidin, which may play a key role in neuroprotection. This study reports the novel neuroprotective activity of GLE, which may be used to develop treatments for neurodegenerative diseases such as Parkinson’s syndrome.

Antioxidant and Anticholinesterase Activities of Extracts and Phytochemicals of Syzygium antisepticum Leaves

Bioassay-guided separation of young leaves extracts of Syzygium antisepticum (Blume) Merr. & L.M. Perry led to the isolation of four triterpenoids (betulinic acid, ursolic acid, jacoumaric acid, corosolic acid) and one sterol glucoside (daucosterol) from the ethyl acetate extract, and three polyphenols (gallic acid, myricitrin, and quercitrin) from the methanol (MeOH) extract. The MeOH extract of S. antisepticum and some isolated compounds, ursolic acid and gallic acid potentially exhibited acetylcholinesterase activity evaluated by Ellman’s method. The MeOH extract and its isolated compounds, gallic acid, myricitrin, and quercitrin, also strongly elicited DPPH radical scavenging activity. In HEK-293 cells, the MeOH extract possessed cellular antioxidant effects by attenuating hydrogen peroxide (H₂O₂)-induced ROS production and increasing catalase, glutathione peroxidase-1 (GPx-1), and glutathione reductase (GRe). Furthermore, myricitrin and quercitrin also suppressed ROS production induced by H₂O₂ and induced GPx-1 and catalase production in HEK-293 cells. These results indicated that the young leaves of S. antisepticum are the potential sources of antioxidant and anticholinesterase agents. Consequently, S. antisepticum leaves are one of indigenous vegetables which advantage to promote the health and prevent diseases related to oxidative stress.

Syzygium gratum Extract Alleviates Vascular Alterations in Hypertensive Rats

Background and Objectives: Syzygium gratum (SG) is a local vegetable and widely consumed in Thailand. Previously, a strong antioxidative effect of SG extract has been reported. The effects of SG extract on hypertension have remained unknown. The effect of SG aqueous extract on blood pressure and vascular changes were examined in L-NAME-induced hypertensive rats (LHR), and its potential active constituents were also explored. Materials and Methods: Male Sprague Dawley rats were allocated to control, L-NAME (40 mg/kg/day), L-NAME + SG (100, 300, 500 mg/kg/day), or captopril (5 mg/kg/day) groups. The components of SG extract were analyzed. Results: The analysis of aqueous SG extract was carried out using HPLC-Mass spectroscopy, and phenolic compounds could be identified as predominant components which might be responsible for its antihypertensive effects observed in the LHR model (p < 0.05). Additionally, SG extract also improved vascular responses to acetylcholine and decreased vascular remodeling in LHR (p < 0.05). Enhancements of eNOS expression and plasma nitric oxide metabolite levels, and attenuation of angiotensin converting enzyme (ACE) activity and plasma angiotensin II levels were observed in the LHR group treated with SG. Moreover, SG exhibited strong antioxidant activities by reducing vascular superoxide generation and systemic malondialdehyde in LHRs. Captopril suppressed high blood pressure and alleviated vascular changes and ACE activity in LHRs, similar to those of the SG extract (p < 0.05). Conclusion: Our results suggest that the SG extract exhibited antihypertensive effects, which is relevant to alleviation of vascular dysfunction and vascular remodeling of LHRs. These effects might be mediated by phenolic compounds to inhibit ACE activity and scavenge reactive oxygen species in LHR.

Complementary Chinese herbal medicine therapy improves survival of patients with gastric cancer in Taiwan: A nationwide retrospective matched-cohort study

ETHNOPHARMACOLOGICAL RELEVANCE

Many patients with gastric cancer seek traditional medicine consultations in Asian countries. This study aimed to investigate the prescription of Chinese herbal medicine (CHM) and its benefits for the patients with gastric cancer in Taiwan.

METHODS

From the Registry for Catastrophic Illness Patients Database, we included all patients with gastric cancer whose age at diagnosis was ≥18 from 1997 to 2010 in Taiwan. We used 1:1 frequency matching by age, sex, Charlson comorbidity score, treatment and index year to compare the CHM users and non-CHM users. We used the Cox regression model to compare the hazard ratios (HR) for the risk of mortality and the Kaplan-Meier curve for the survival time.

RESULTS

There was a total of 1333 patients in the CHM-cohort and 44786 patients in the non-CHM cohort. After matching, we compared 962 newly diagnosed CHM users and 962 non-CHM users. Adjusted HRs (aHR) were higher among patients of above 60-year-old group, with a Charlson Comorbidity Index score ≥2 before the index date, and those who need surgery combined with chemotherapy or radiotherapy. CHM users had a lower HR of mortality risk (adjusted HR: 0.55, 95% CI: 0.48-0.62). Compared to the non-CHM users, the aHR among CHM-users is 0.37 (95% CI:0.2-0.67) for those who used CHM more than 180 days annually. The Kaplan-Meier curve revealed that the survival probability was higher for complementary CHM-users. Bai-Hua-She-She-Cao (Herba Hedyotidis Diffusae) was the most commonly used single herb and Xiang-Sha-Liu-Jun-Zi-Tang was the most commonly used herbal formula among CHM prescriptions.

CONCLUSIONS

Complementary CHM improves the overall survival among patients with gastric cancer in Taiwan. Further ethnopharmacological investigations and clinical trials are required to validate the efficacy and safety.

Antioxidant, antibacterial activity, and phytochemical characterization of Melaleuca cajuputi extract

Background

The threat posed by drug-resistant pathogens has resulted in the increasing momentum in research and development for effective alternative medications. The antioxidant and antibacterial properties of phytochemical extracts makes them attractive alternative complementary medicines. Therefore, this study evaluated the phytochemical constituents of Melaleuca cajuputi flower and leaf (GF and GL, respectively) extracts and their antioxidant and antibacterial activities.

Methods

Radical scavenging capacity of the extracts was estimated using 2,2-diphenyl-2-picrylhydrazyl and Fe²⁺-chelating activity. Total antioxidant activity was determined using ferric reducing antioxidant power assay. Well diffusion, minimum inhibitory concentration, and minimum bactericidal concentration assays were used to determine antibacterial activity against eight pathogens, namely Staphylococcus aureus, Escherichia coli, Bacillus cereus, Staphylococcus epidermidis, Salmonella typhimurium, Klebsiella pneumonia, Streptococcus pneumoniae, and Pasteurella multocida. We identified and quantified the phytochemical constituents in methanol extracts using liquid chromatography/mass spectrometry (LC/MS) and gas chromatography (GC)/MS.

Results

This study reports the antioxidant and radical scavenging activity of M. cajuputi methanolic extracts. The GF extract showed better efficacy than that of the GL extract. The total phenolic contents were higher in the flower extract than they were in the leaf extract (0.55 ± 0.05 and 0.37 ± 0.05 gallic acid equivalent per mg extract dry weight, respectively). As expected, the percentage radical inhibition by GF was higher than that by the GL extract (81 and 75 %, respectively). A similar trend was observed in Fe²⁺-chelating activity and β-carotene bleaching tests. The antibacterial assay of the extracts revealed no inhibition zones with the Gram-negative bacteria tested. However, the extracts demonstrated activity against B. cereus, S. aureus, and S. epidermidis.

Conclusions

In this study, we found that M. cajuputi extracts possess antioxidant and antibacterial activities. The results revealed that both extracts had significant antioxidant and free radical-scavenging activity. Both extracts had antibacterial activity against S. aureus, S. epidermidis, and B. cereus. The antioxidant and antimicrobial activities could be attributed to high flavonoid and phenolic contents identified using GC/MS and LC/MS. Therefore, M. cajuputi could be an excellent source for natural antioxidant and antibacterial agents for medical and nutraceutical applications.

High resolution scanning electron microscopy of cells using dielectrophoresis

Ultrastructural analysis of cells can reveal valuable information about their morphological, physiological, and biochemical characteristics. Scanning electron microscopy (SEM) has been widely used to provide high-resolution images from the surface of biological samples. However, samples need to be dehydrated and coated with conductive materials for SEM imaging. Besides, immobilizing non-adherent cells during processing and analysis is challenging and requires complex fixation protocols. In this work, we developed a novel dielectrophoresis based microfluidic platform for interfacing non-adherent cells with high-resolution SEM at low vacuum mode. The system enables rapid immobilization and dehydration of samples without deposition of chemical residues over the cell surface. Moreover, it enables the on-chip chemical stimulation and fixation of immobilized cells with minimum dislodgement. These advantages were demonstrated for comparing the morphological changes of non-budding and budding yeast cells following Lyticase treatment.