Asian Journal of Research in Zoology

Dalbergia sissoo Roxb. is a widely used medicinal plant with numerous pharmacological properties; however, scientific evidence regarding its reproductive safety remains inadequate. The present study was undertaken to evaluate the dose-dependent effects of aqueous and ethanolic leaf extracts of Dalbergia sissoo on testicular histoarchitecture in male Swiss albino mice following repeated oral administration.

Fifty healthy adult male Swiss albino mice were randomly allocated to five groups, with 10 mice in each group (n = 10). Group I (Control) received 1 mL/kg b.wt. of normal saline, which served as the vehicle control; Group II received aqueous leaf extract at a dose of 200 mg/kg b.wt.; Group III received aqueous leaf extract at a dose of 300 mg/kg b.wt.; Group IV received ethanolic leaf extract at a dose of 200 mg/kg b.wt.; Group V received ethanolic leaf extract at a dose of 300 mg/kg b.wt.

At the end of the experimental period, testes were excised, fixed in Bouin's fixative, processed routinely, stained with haematoxylin and eosin (H&E), and examined microscopically for histopathological alterations. Histopathological examination revealed normal seminiferous tubules with complete spermatogenic series and abundant mature spermatozoa in the control group. Administration of the aqueous leaf extract at 200 mg/kg b.wt. produced mild degeneration of the germinal epithelium, occasional cytoplasmic vacuolation, and a slight reduction in sperm density. At 300 mg/kg b.wt., the aqueous extract induced marked degeneration of seminiferous tubules, disruption of spermatogenesis, widening of the interstitial spaces and a pronounced decline in mature spermatozoa.

The ethanolic leaf extract produced more pronounced histopathological effects than the aqueous extract. Mice treated with 200 mg/kg ethanolic extract exhibited mild degeneration of seminiferous tubules, cytoplasmic vacuolation, germ-cell disorganisation and reduced spermatogenesis, whereas administration of 300 mg/kg resulted in severe tubular atrophy, depletion of the germinal epithelium, degeneration of Leydig cells, widening of interstitial spaces and near-complete absence of mature spermatozoa. The severity of the histopathological lesions increased in a dose-dependent manner and was more pronounced in the ethanolic extract-treated groups than in the corresponding aqueous extract-treated groups.

The findings indicate that repeated oral exposure to Dalbergia sissoo leaf extracts, particularly the ethanolic extract at higher doses, adversely affects testicular histoarchitecture and spermatogenesis in male Swiss albino mice under the present experimental conditions.

Future studies are recommended to isolate and characterise the phytochemical constituents responsible for the observed reproductive toxicity, elucidate the underlying molecular and endocrine mechanisms, evaluate oxidative stress and apoptotic pathways, investigate the reversibility of testicular damage following withdrawal of treatment, assess fertility outcomes in long-term toxicity models, and establish evidence-based safe therapeutic dosage ranges before medicinal use of Dalbergia sissoo leaf preparations in humans.