Multifaceted anti-infective efficacy of Alstonia scholaris (Mizoram chemotype) against fungal, malarial, and intestinal helminth pathogens: in vitro validation and molecular docking insights.

BACKGROUND AND AIM: The increasing prevalence of drug-resistant fungal, malarial, and helminth infections necessitates the identification of novel, broad-spectrum therapeutic agents. Alstonia scholaris, widely used in Mizo traditional medicine, has been reported for treating microbial and parasitic infections. This study aimed to evaluate the multifaceted anti-infective efficacy of a geographically distinct Mizoram chemotype of A. scholaris through in vitro assays and molecular docking analyses.

MATERIALS AND

METHODS

Methanolic bark extract of A. scholaris was assessed for antifungal activity against Aspergillus fumigatus, Candida albicans, and Neocosmospora keratoplastica using the agar poison technique. Antimalarial activity was tested against chloroquine-sensitive (3D7) and multidrug-resistant (K1) strains of Plasmodium falciparum using a SYBR Green I-based fluorescence assay. Cytotoxicity was evaluated in Vero C1008 cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Anthelmintic efficacy was determined against Raillietina echinobothrida using histological and scanning electron microscopy analyses. Bioactive compounds were identified by gas chromatography-mass spectrometry (GC-MS), followed by molecular docking against key pathogen targets.

RESULTS

The extract demonstrated significant antifungal activity, with N. keratoplastica being the most susceptible species. Antimalarial activity showed comparable efficacy against both P. falciparum strains, with IC50 values of 43.40 µg/mL (3D7) and 45.60 µg/mL (K1), and a low resistance index of 1.05. Cytotoxicity analysis indicated high CC50 (>100 µg/mL), suggesting safety, although selectivity indices were moderate. Anthelmintic activity revealed concentration-dependent effects, comparable to albendazole (p > 0.05). Histological and ultrastructural analyses confirmed severe tegumental and internal tissue damage in parasites. GC-MS identified triterpenoids, predominantly α-amyrin and kolavenol. Docking studies revealed strong binding affinities of α-amyrin with fungal sterol 14α-demethylase (CYP51, at -10.4 kcal/mol), malarial S-adenosyl-L-homocysteine hydrolase (SAHH, at -10.0 kcal/mol), and helminth glutamate-gated chloride channel (GluCl, at -9.4 kcal/mol), supporting multi-target activity.

CONCLUSION

The Mizoram chemotype of A. scholaris exhibits broad-spectrum anti-infective potential with antifungal, antimalarial, and anthelmintic activities. The predominance of triterpenoids, particularly α-amyrin and kolavenol, distinguishes it from other chemotypes and underpins its pharmacological profile. These findings validate its traditional use and highlight its potential as a source of novel anti-infective agents, warranting further in vivo and mechanistic studies.