Volume 166, 26 May 2015, Pages 129–134
Abstract
Ethnopharmacological relevance
Shilajit,
a herbomineral substance exuded from rocks in steep mountainous
regions, has been used for thousands of years by the Indian Ayurvedic
and Siddha systems of traditional medicine to relieve ailments and
enhance quality of life. Although a large number of therapeutic
properties have been ascribed to Shilajit, its therapeutic potential is
still largely unexplored by modern research and many of its claimed
bioactivities lack scientific validation. The present study was
undertaken to investigate the antiviral activity of Shilajit against a
panel of viruses including herpes simplex type 1 and 2 (HSV-1, HSV-2),
human cytomegalovirus (HCMV), human respiratory syncytial virus (RSV),
human rotavirus (HRV), and vesicular stomatitis virus (VSV).
Materials and methods
The antiviral activity of Shilajit was assayed in vitro
by plaque reduction and virus yield assays and the major mechanism of
action was investigated by virucidal and time-of-addition assays.
Results
Shilajit exhibited a dose-dependent inhibitory activity against HSV1, HSV2, HCMV, and RSV infectivity in vitro (EC50
values: 31.08 μg/ml, 12.85 μg/ml, 34.54 μg/ml, and 30.35 μg/ml,
respectively), but was inactive against HRV and VSV. Humic acid, a
constituent of Shilajit, displayed the same spectrum of activity.
Partial virus inactivation and interference with virus attachment were
both found to contribute to the antiviral activity of Shilajit.
Conclusions
The results of the present study demonstrate that Shilajit is endowed with broad, yet specific, antiviral activity in vitro and constitutes a natural source of antiviral substances. Further work remains to be done to assess its efficacy in vivo.
Keywords
- Shilajit;
- Ayurvedic medicine;
- Humic acid;
- Antiviral;
- Mechanism of action;
- Virus
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