Catalog NumberHG84696219
CAS Number84696-21-9
CategoryNatural surfactants
Use as antibacterial agent.
Centella asiatica Extract: Comparative Antimicrobial and Antioxidant Activity
Vaddadi, Sneha, et al. Adv. Biotechnol. Microbiol 3 (2017): 555618.
The antimicrobial and antioxidant activities of root, stem, and leaf extracts of Centella asiatica were systematically compared to identify the tissue with the highest bioactive potential, with special attention to secondary metabolite profiles including phenols, flavonoids, and tannins.
Experimental Protocol: Three-month-old plants were harvested and separated into root, stem, and leaf tissues. Extracts were prepared using ethanol, petroleum ether, and chloroform. Antimicrobial activity was tested against Escherichia coli, Staphylococcus aureus, Aspergillus niger, and Rhizopus stolonifer using the minimum inhibitory concentration (MIC) method with p-iodonitrotetrazolium violet indicator. Antioxidant capacity was assessed via DPPH, superoxide, hydroxyl radical, and H2O2 scavenging assays. Enzymatic antioxidants (SOD, APX, PPO), non-enzymatic antioxidants (ascorbic acid, glutathione, alpha-tocopherol), and secondary metabolites (phenols, flavonoids, tannins, terpenes, alkaloids, saponins, steroids) were quantified.
Performance Evaluation: Ethanol extracts demonstrated superior antimicrobial activity compared to petroleum ether and chloroform extracts. Leaf ethanol extract showed the strongest activity with MIC values of 7.8 mg/mL against S. aureus and 31.25 mg/mL against A. niger. The extracts exhibited higher efficacy against fungal strains than bacterial strains. Leaf tissues possessed significantly higher total antioxidant content, ascorbic acid, glutathione, alpha-tocopherol, and SOD/APX activities compared to stem and root. Phenol, flavonoid, and tannin contents were highest in leaves, and PPO activity (both catechol oxidase and laccase) was spectrometrically confirmed with characteristic absorption at 495 nm. The superior bioactivity of leaf extracts was attributed to their elevated secondary metabolite concentrations.
Centella asiatica Extract Phytochemistry and Neuroprotective/Cognitive Enhancement Mechanisms
Gray, Nora E., et al. Phytochemistry Reviews 17.1 (2018): 161-194.
The phytochemistry and neurological mechanisms of Centella asiatica were comprehensively reviewed, highlighting the roles of pentacyclic triterpenes and caffeoylquinic acids as the principal bioactive compound classes responsible for neuroprotection and cognitive enhancement.
This review synthesized evidence from preclinical studies (in vitro and rodent models), phytochemical analyses using liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS), and clinical studies employing standardized extracts including TTFCA (total triterpenic fraction) and TECA (titrated extract). Compound classes examined included isoprenoids (sesquiterpenes, plant sterols, pentacyclic triterpenoids, and saponins) and phenylpropanoid derivatives (eugenol derivatives, caffeoylquinic acids, and flavonoids). Neuroprotective assays included beta-amyloid toxicity models, mitochondrial activity measurements, and antioxidant status evaluation.
Key Findings: Neuroprotective effects were demonstrated in multiple in vitro models, particularly against beta-amyloid toxicity, and were associated with increased mitochondrial activity, improved antioxidant status, and inhibition of the pro-inflammatory enzyme phospholipase A2. Neurotropic effects included increased dendritic arborization and synaptogenesis, potentially mediated through ERK1/2 and Akt signal transduction pathways. The triterpenes asiatic acid, asiaticoside, and madecassoside were identified as the primary neuroactive compounds. Caffeoylquinic acids emerged as a second important group, with the potential to activate the Nrf2-antioxidant response pathway. Absorption, distribution, metabolism, and excretion studies confirmed that triterpenes, caffeoylquinic acids, and flavonoids or their metabolites reached the brain in both animal models and humans.