Special Issue "Plant Extracts: Biological and Pharmacological Activity"

Phytochemical Analysis and Assessment of Antioxidant and Enzyme Inhibitory Activity of Alchemilla pseudocartalinica Juz

This study aimed to evaluate and compare the antioxidant capacity and enzyme inhibitory activity of extracts, sub-extracts, and fractions prepared from the aerial parts and roots of A. pseudocartalinica. The phytochemical content of the active extracts was also analyzed. According to the results, ellagic acid (38.42 mg/g) was the major compound in the aerial part methanol extract and catechin (185.30 mg/g) in the root methanol extract. The DPPH inhibition activity of all fractions was monitored, with the most active one (Fr B) reaching an IC50 value of (4.92±0.59 μg/mL). All the fractions prepared from the aerial parts' water sub-extract showed higher a-glucosidase inhibitory activity than the positive control acarbose. In the tyrosinase assay, Fr B (58.81±7.50 μg/mL) exhibited the highest inhibitory actions among all fractions. The structure of the major substances of the most active fraction were elucidated as quercetin 7-O-β-glucopyranosyl-3-O-β-glucuronopyranoside- (1), and α-[(2-formyl-5-hydroxymethyl)pyrrol-1-yl]aspartic acid (2).

Asiatic acid reduces lipopolysaccharides-induced pulp inflammation through activation of nuclear factor erythroid 2-related factor 2 in rats

Background

Dental pulp inflammation, often initiated by Gram-negative microorganisms and lipopolysaccharides (LPS), can lead to pulpitis and, subsequently, dental pulp necrosis, compromising tooth structure and increasing susceptibility to fracture. Asiatic acid, derived from Centella asiatica, has demonstrated pharmacological properties, including anti-inflammatory and antioxidant effects, making it a potential candidate for mitigating LPS-induced pulp inflammation. This in vivo study aims to investigate the impact of Asiatic acid on the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in Rattus norvegicus with LPS-induced pulp inflammation.

Methods

This quasi-laboratory experimental in vivo study employed a post-test-only control group design to investigate the effects of Asiatic acid on LPS-induced pulp inflammation in Wistar rats. Thirty rats were randomly divided into six groups subjected to various interventions. LPS was administered to all groups for 6 h except the standard control group (CG, n = 5). The negative control group (NCG, n = 5) received only glass ionomer cement. The positive control group (PCG, n = 5) received Eugenol with glass ionomer cement. Intervention groups 1, 2, and 3 (IG1, IG2, IG3; n = 5 each) received Asiatic acid at concentrations of 0.5%, 1%, and 2%, respectively, with glass ionomer cement. Dental pulp inflammation was confirmed through immunological (tumor necrosis factor alpha (TNF-α) levels), histopathological (inflammatory parameters), and physiological (pain assessment using the rat grimace scale) analyses. Additionally, Nrf2 levels were examined using enzyme-linked immunosorbent assay (ELISA).

Results

Asiatic acid administration significantly influenced Nrf2 levels in rats with LPS-induced pulp inflammation. Nrf2 levels were significantly higher in groups treated with 0.5% (IG1) (8.810 ± 1.092 ng/mL; p = 0.047), 1.0% (IG2) (9.132 ± 1.285 ng/mL; p = 0.020), and 2.0% (IG3) (11.972 ± 1.888 ng/mL; p = 0.000) Asiatic acid compared to NCG (7.146 ± 0.706). Notably, Nrf2 levels were also significantly higher in the 2.0% Asiatic acid group (IG3) compared to the PCG treated with Eugenol (8.846 ± 0.888 ng/mL; p = 0.001), as well as IG1 (p = 0.001) and IG2 (p = 0.002). However, no significant difference was observed between administering 0.5% Asiatic acid (IG1), 1.0% Asiatic acid (IG2), and Eugenol (PCG).

Conclusion

This research showed that Asiatic acid significantly impacted the Nrf2 levels in rats with LPS-induced pulp inflammation. This suggests that it has the potential to be used as a therapeutic agent for reducing dental pulp inflammation. These findings support the need to further explore Asiatic acid as a promising intervention for maintaining dental pulp health.

Evaluation of Free Radical Scavenging and Antimicrobial Activity of Coleus amboinicus-Mediated Iron Oxide Nanoparticles

Background In this research, iron oxide nanoparticles were synthesized using Coleus amboinicus stem extract, which is used for various diseases such as throat infection, cough, fever, nasal congestion, and digestive problems.  Aim This study aimed to formulate a green synthesis of iron oxide nanoparticles mediated by Coleus amboinicus (known as karpuravalli in Tamil) and assess its antimicrobial and antioxidant properties.  Materials and methods Iron oxide nanoparticles were synthesized, and then their antimicrobial properties were tested against two specific pathogens, i.e., Streptococcus mutans and Candida albicans, using the agar well diffusion technique. The 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, hydroxyl radical scavenging (H2O2) assay, and ferric ion reducing antioxidant power (FRAP) assay were conducted to check the free radical scavenging activity.  Result The results obtained showed that these iron oxide nanoparticles showed better antimicrobial activity against Streptococcus mutans when compared to Candida albicans, and the antioxidant activity showed a very close efficacy when compared to the standard.  Conclusion The research has demonstrated the high antioxidant activity and high antibacterial activity of iron oxide nanoparticles using Coleus amboinicus stem, a natural and cheaper antimicrobial drug compared to the drugs present on the market.

Anti-inflammatory, Analgesic, and Cytotoxic Effects of The Phytexponent: A Polyherbal Formulation

The Phytexponent is used to treat pain and inflammation in complementary and alternative medicine practices; however, empirical data supporting its pharmacological efficacy and safety is scanty, hence the present study. We used the carrageenan-induced paw oedema and the acetic acid-induced writhing techniques to determine the anti-inflammatory and analgesic efficacies, respectively, of the Phytexponent in Swiss albino mice models. The 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay technique was used to investigate the in vitro cytotoxic effects of the Phytexponent in the Vero E6 cell line. The Phytexponent exerted significant (P < .05) anti-inflammatory effects in the carrageenan-induced paw oedema mouse model in a dose- and time-dependent manner, with significantly higher efficacy at 250 mg/Kg BW, than indomethacin (4 mg/Kg BW), in the first, second, and third hour (P < .05). Besides, the Phytexponent significantly reduced the acetic acid-induced writhing frequency in mice (P < .05), in a dose-dependent manner, depicting its analgesic efficacy. Notably, the Phytexponent (at doses: 125 mg/Kg BW and 250 mg/Kg BW) exhibited significantly higher analgesic efficacy than the Indomethacin (P<.05). Moreover, the Phytexponent was not cytotoxic to Vero E6 cells (CC₅₀ >1000 µg/ml) compared to cyclophosphamide (CC₅₀ = 2.48 µg/ml). Thus, the Phytexponent has significant in vivo anti-inflammatory and analgesic efficacy in mice models and is not cytotoxic to Vero E6 cell line, depicting its therapeutic potential upon further empirical investigation.