Antioxidant and antiaging effect of traditional Thai rejuvenation medicines in Caenorhabditis elegans

Exploring Antioxidant Properties of Standardized Extracts from Medicinal Plants Approved by the Thai FDA for Dietary Supplementation

BACKGROUND/OBJECTIVES

There is a growing interest in plant-derived antioxidants as functional food ingredients, given their potential to address oxidative stress-related diseases, notably neurodegenerative disorders. This study aims to investigate the antioxidant properties of medicinal plants that have been approved by the Thai FDA for dietary supplementation, with the goal of further utilizing them as food-functional ingredients to prevent neurodegenerative conditions.

METHODS

A systematic review-based methodology was employed on a list of 211 medicinal plants, and 21 medicinal plants were chosen based on their documented antioxidant activity and acetylcholinesterase (AChE) inhibitory capacity. The 21 commercially available standardized extracts were subjected to evaluation for their phenolic and flavonoid content, as well as their antioxidant activities utilizing metal-chelating activity, DPPH, ABTS free radical scavenging, ferric-reducing antioxidant power (FRAP), and superoxide anion scavenging techniques.

RESULTS

Among the 21, six extracts-Bacopa monnieri, Camellia sinensis, Coffea arabica, Curcuma longa, Tagetes erecta, and Terminalia chebula-emerged as the most promising. These extracts exhibited elevated levels of phenolic (up to 1378.19 mg gallic acid equivalents per gram) and flavonoids, with Coffea arabica and Curcuma longa showing the strongest antioxidant and free radical scavenging activities, indicating their potential for use in functional foods aimed at delaying neurodegenerative diseases.

CONCLUSIONS

Due to their high levels of phenolic and flavonoid compounds, along with strong metal-chelating abilities and significant free radical scavenging activities, these standardized extracts show potential for functional food applications that may help delay the onset of neurodegenerative diseases.

Ultrasonic collaborative pulse extraction of sugarcane polyphenol with good antiaging and α-glucosidase inhibitory activity

Sugarcane, as one important and heavily planted industrial crop, is meaningful to develop its byproducts. In this paper, the ultrasonic collaborative pulse was beneficial for the yield improvement and good bioactivity protection. The sugarcane polyphenol extract (SPE) yield reached 2.42 ± 0.08 mg/g DW at the optimized conditions: pulse time of 60 s, pulse intensity of 2 kV/cm, ultrasonic time of 90 min, and ultrasonic power of 120 W. The SPE contained the total phenolic content of 6.01 ± 0.12 mg GAE/g extract and total flavonoids content of 7.15 ± 0.24 mg RE/g extract. The SPE was mainly composed of chlorogenic acid, schaftoside, hyperoside, quercitrin, and trans-3-hydroxycinnamic acid with 10.24 %, 14.92 %, 4.22 %, 12.05 %, 25.54 %, respectively. The SPE showed good radical scavenging activity with ORAC value of 134.57 μmol/g. The SPE could reduce the oxidative stress and extend the mean lifespan of nematodes by 7.19 % in vivo through increasing the activity of SOD and CAT to decrease the ROS level and MDA content. In addition, the SPE showed strong α-glucosidase inhibitory activity with IC50 of 0.53 mg/mL in a mixed inhibition type, which suggested that the SPE had good hypoglycemic potential.

Preparation of paeoniflorin-glycyrrhizic acid complex transethosome gel and its preventive and therapeutic effects on melasma

Paeoniflorin (PF) and glycyrrhizic acid (GL) have skin beautifying effects of anti-inflammation, anti-oxidation, inhibition of melanin formation, and reduction of skin pigmentation. To improve the transdermal permeability of PF and GL in transdermal drug delivery system (TDDS) and enhance their anti-melasma efficacy, PF-GL transethosome (PF-GL-TE) was prepared by ethanol injection method, and finally gelled with carbomer-940 to form PF-GL-TE gel. Consequently, the obtained PF-GL-TE is small and uniform, with an average particle size and a PDI value of about 167.9 nm and 0.102. PF-GL-TE gel showed sustained release behavior and high transdermal permeability in vitro release and transdermal tests. Meanwhile, PF-GL-TE gel played significant preventive effects on melasma induced by progesterone injection and ultraviolet radiation B (UVB) irradiation. According to the results of H&E staining and Masson staining of rat skin, PF-GL-TE gel can alleviate the skin inflammation of and reduce the loss of collagen fibers of back skin in the melasma model rats. Compared with the PF-GL mixture gel, PF-GL-TE gel significantly attenuated the oxidative damage of liver and skin by increasing the activity of SOD and reducing the content of MDA. The results of Western blot showed that PF-GL-TE gel might down-regulate melanin-related proteins expressions of MITF/TYR/TRP1 and TRP2 to prevent and treat melasma. These findings indicate that PF-GL-TE gel is an effective TDDS for delivering PF and GL into the skin, providing a promising preparation for effective prevention and treatment of melasma.

Antioxidant Peptides Derived from Millet Bran Promote Longevity and Stress Resistance in Caenorhabditis elegans

Millet bran as a by-product of millet grain processing remains a reservoir of active substances. In this study, functional millet bran peptides (MBPE) were obtained from bran proteins after alcalase hydrolysis and ultrafiltration. The activity of MBPE was assessed in vitro and in the model organism Caenorhabditis elegans (C. elegans). In vitro, compared to unhydrolyzed proteins, MBPE significantly enhanced the 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-Azinobis-(3-ethylbenzthiazoline-6-sulphonate (ABTS) and hydroxyl radicals scavenging activity, and the scavenging rate of MBPE with 15,000 U/g alcalase reached 42.79 ± 0.31%, 61.38 ± 0.41 and 45.69 ± 0.84%, respectively. In C. elegans, MBPE at 12.5 µg/mL significantly prolonged the lifespan by reducing lipid oxidation, oxidative stress, and lipofuscin levels. Furthermore, MBPE increased the activities of the antioxidant enzymes. Genetic analyses showed that MBPE-mediated longevity was due to a significant increase in the expression of daf-16 and skn-1, which are also involved in xenobiotic and oxidative stress responses. In conclusion, this study found that MBPE had antioxidant and life-prolonging effects, which are important for the development and utilization of millet bran proteins as resources of active ingredients.

Physicochemical properties and biological activities of Tremella hydrocolloids

In this paper, the physicochemical properties, antioxidant and anti-aging abilities of three new Tremella hydrocolloids were studied. The physicochemical properties were characterized by Fourier transform infrared spectroscopy, differential scanning calorimeter, X-ray diffractometry etc. The antioxidant activities of Tremella hydrocolloids were determined by ABTS radical, DPPH radical scavenging activity. The anti-aging ability of Tremella hydrocolloids was also investigated by using the organism model of Caenorhabditis elegans (C. elegans). The results showed that the ES-THD displayed the highest radical scavenging capacity and the best anti-aging abilities. The ability of ES-THD to scavenge ABTS radicals reached 100 % at 2 mg/mL, the ability of ES-THD to scavenge DPPH radicals reached 45.55 %. Compared with the control group, the average lifespan was 29.17 % longer fed with ES-THD. These results provide the evidence basis for the use of Tremella hydrocolloids as food texture modifiers, antioxidants, and anti-aging agents in the food industries.

In Vitro, In Vivo, and In Silico Analyses of Molecular Anti-Pigmentation Mechanisms of Selected Thai Rejuvenating Remedy and Bioactive Metabolites

Thai rejuvenating remedies are mixed herbal formulas promoting longevity. Due to the complexity, the biological activities of these remedies are minimal. Therefore, in this study, the authors evaluated the anti-pigmentation effect at the molecular level of the selected Thai rejuvenating remedy to fulfill the knowledge gap. First, the authors found that the selected remedy showed promising activity against the tyrosinase enzyme with an IC₅₀ value of 9.41 µg/mL. In the comparison, kojic acid (positive control) exhibited an IC₅₀ value of 3.92 µg/mL against the same enzyme. Later, the authors identified glabridin as a bioactive molecule against tyrosinase with an IC₅₀ value of 0.08 µg/mL. However, ethyl p-methoxycinnamate was the most abundant metabolite found in the remedy. The authors also found that the selected remedy and glabridin reduced the melanin content in the cell-based assay (B16F1) but not in the zebrafish larvae experiment. Finally, the authors conducted a computational investigation through molecular docking proposing a theoretical molecular interplay between glabridin, ethyl p-methoxycinnamate, and target proteins (tyrosinase and melanocortin-1 receptor, MC1R). Hence, in this study, the authors reported the molecular anti-pigmentation mechanism of the selected Thai rejuvenating remedy for the first time by combining the results from in silico, in vitro, and in vivo experiments.

Fosthiazate exposure induces oxidative stress, nerve damage, and reproductive disorders in nontarget nematodes

As a forceful nematicide, fosthiazate has been largely applied in the management of root-knot nematodes and other herbivorous nematodes. However, the toxicity of fosthiazate to nontarget nematodes is unclear. To explore the toxicity and the mechanisms of fosthiazate in nontarget nematodes, Caenorhabditis elegans was exposed to 0.01-10 mg/L fosthiazate. The results implied that treatment with fosthiazate at doses above 0.01 mg/L could cause injury to the growth, locomotion behavior, and reproduction of the nematodes. Moreover, L1 larvae were more vulnerable to fosthiazate exposure than L4 larvae. Reactive oxygen species (ROS) production and lipofuscin accumulation were fairly increased in 1 mg/L fosthiazate-exposed nematodes. Treatment with 0.1 mg/L fosthiazate significantly inhibited the activity of acetylcholinesterase (p < 0.01). Furthermore, subacute exposure to 10 mg/L fosthiazate strongly influenced the expression of genes related to oxidative stress, reproduction, and nerve function (e.g., gst-1, sod-1, puf-8, wee-1.3, and ace-1 genes). These findings suggested that oxidative stress, reproduction and nerve disorders could serve as key endpoints of toxicity induced by fosthiazate. The cyp-35a family gene was the main metabolic fosthiazate in C. elegans, and the cyp-35a5 subtype was the most sensitive, with a change in expression level of 2.11-fold compared with the control. These results indicate that oxidative stress and neurological and reproductive disorders played fundamental roles in the toxicity of fosthiazate in C. elegans and may affect the abundance and function of soil nematodes.