Investigating structural aspects to understand the putative/claimed non-toxicity of the Hg-based Ayurvedic drug Rasasindura using XAFS.
XANES- and EXAFS-based analysis of the Ayurvedic Hg-based nano-drug Rasasindura has been performed to seek evidence of its non-toxicity. Rasasindura is determined to be composed of single-phase α-HgS nanoparticles (size ∼24 nm), free of Hg(0) or organic molecules; its structure is determined to be robust (<3% defects). The non-existence of Hg(0) implies the absence of Hg-based toxicity and establishes that chemical form, rather than content of heavy metals, is the correct parameter for evaluating the toxicity in these drugs. The stable α-HgS form (strong Hg-S covalent bond and robust particle character) ensures the integrity of the drug during delivery and prevention of its reduction to Hg(0) within the human body. Further, these comparative studies establish that structural parameters (size dispersion, coordination configuration) are better controlled in Rasasindura. This places the Ayurvedic synthesis method on par with contemporary techniques of nanoparticle synthesis.
High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Purnima Labs Trombay, Mumbai, Maharashtra 400085, India.
Nitya
N
Ramanan
High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Purnima Labs Trombay, Mumbai, Maharashtra 400085, India.
Debdutta
D
Lahiri
Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Purnima Labs Trombay, Mumbai, Maharashtra 400085, India.
Parasmani
P
Rajput
Arya Vaidya Sala, Kottakkal, Kerala 676503, India.
Ramesh Chandra
RC
Varma
Arya Vaidya Sala, Kottakkal, Kerala 676503, India.
A
A
Arun
Arya Vaidya Sala, Kottakkal, Kerala 676503, India.
T S
TS
Muraleedharan
High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Purnima Labs Trombay, Mumbai, Maharashtra 400085, India.
K K
KK
Pandey
Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai, Maharashtra 400085, India.
Nandita
N
Maiti
Atomic and Molecular Physics Division, Bhabha Atomic Research Centre, Purnima Labs Trombay, Mumbai, Maharashtra 400085, India.
S N
SN
Jha
High Pressure and Synchrotron Radiation Physics Division, Bhabha Atomic Research Centre, Purnima Labs Trombay, Mumbai, Maharashtra 400085, India.
Surinder M
SM
Sharma
D001682:Biological Availability; D003460:Crystallization; D004339:Drug Compounding; D008515:Medicine, Ayurvedic; D008628:Mercury / Q000032:analysis*; D017669:Mercury Compounds / Q000032:analysis* / Q000138:chemical synthesis / Q000737:chemistry* / Q000633:toxicity; D053758:Nanoparticles; D010316:Particle Size; D011208:Powders; D012995:Solubility; D056928:X-Ray Absorption Spectroscopy / Q000379:methods*
D017669:Mercury Compounds; D011208:Powders; D008628:Mercury; C034211:cinnabar
Ayurvedic drug; Hg; XAFS; toxicity