Different methods of preparing Swarna bhasma
have been reported in various Ayurvedic
] This has been done by the incineration of gold with various compounds like mercury, mercury sulfide, sulfur, orpiment (As2
), realgar (AsS), chalcopyrite, etc. out of which the procedure with mercury is considered to be therapeutically effective.[26
] Various attempts have been done on the standardization of Swarna bhasma
preparations for clinical applications.[27
] However, the blood compatibility aspects have not been investigated till now.
Although the particle sizes of different batches showed similarity, it seems that these particles are aggregates of much smaller particles. When dispersed in an aqueous medium, gold colloids form a negatively charged hydrophobic particle suspension. This hydrophobicity gives these gold particles a tendency to aggregate together to form larger particles.[28
] Both batches of Swarna bhasma
exhibited larger sizes and agglomeration of the particles. However, the crystallite size calculated from XRD was much smaller. Therefore, the comparatively larger size may be due to the agglomeration of the particles by repeated cycles of calcinations involved in preparation as reported earlier.[29
] Zeta potential has been suggested to play an important role in particle uptake because the surface of the intestinal mucosa is negatively charged owing to the presence of glycocalix. Particles with a high positive surface charge like chitosan are usually attracted by the intestinal mucosa, which helps in increasing the intestinal absorption of the encapsulated drug. However, the strong electrostatic interaction between the positively charged particles and the negatively charged glycocalix may slow down the progression and penetration of these particles towards the epithelial cell surface reducing their uptake. Also it has been shown that non-ionized particles have a greater affinity for M cells than for ionized particles[30
] and positively charged particles.[31
] It has been suggested that gold bhasma
particles with low negative zeta potential and nanosize may be uptaken by a similar manner.
The X-ray diffraction peaks at 2θ = 38.2°, 44.4°, 64.6° and 77.6° of Swarna bhasma
were identical with those reported for the standard gold metal (Au°) (JCPDS File No. 04-0784). No other major diffraction peaks were observed confirming that the Swarna bhasma
is composed of mainly gold nanoparticles. The high intensity of XRD lines in the XRD pattern suggests its crystalline nature. It has been reported that nanoparticles exhibited a size-dependent uptake from the intestine, and its passage via the mesentery lymph supply and lymph nodes to the liver,[32
] with significant absorption for particles less than 100 nm. Therefore, uptake of Swarna bhasma
particles of 28 nm through the intestine can be expected.
From the EDAX results it was confirmed that 90% of Swarna bhasma
contains pure gold and is in correlation with XRD data. EDAX provide good estimate of the concentration of main elements in the sample in a significantly faster way and provides useful information on the distribution of the element forming the sample and their possible chemical form.[34
multi-ingredient compounds are formulated in a way that the ingredients are capable of counter-balancing toxic effects, if any, present in the herbs or metals (bhasma
] These particles pass through extensive processing before they are declared fit for internal use. The processes consist of Shodhan
. Culture of various cell types with colloidal gold showed no evidence of cytotoxicity.[36
] No in vivo cytotoxicity has been reported with the use of colloidal gold administrated intravenously to ponies and pigs at doses of 400 mg of gold.[40
] The initial event when a material comes in contact with blood is the adsorption of proteins. The nature of protein and amount of protein adsorbed will directly influence the compatibility of the particles with the blood. There was a correlation of the adsorption of the globular proteins with the blood cell aggregation showing no activation or aggregation of cells on incubation with Swarna bhasma
. Activation of platelets initiates the deformation of the cells with pseudopod formation and ends with blood coagulation or thrombus formation.[41
] In the present study platelets seem to be not activating and adhering onto the bhasma
particles and even the very few platelets adhered are not activated as seen from their round shape. This is an indication of the very high platelet compatibility of Swarna bhasma
One of the negative effects of the clinical application of various blood-contacting materials is the activation of the complement system induced by the foreign surface. The response of blood in contact with the material depends on physicochemical features such as surface area, surface charge, hydrophobicity/hydrophilicity etc. The response depends directly on the surface area. Adsorption of C3 triggers complement activation.[41
] It has been demonstrated in this study that the adsorptions of C3 on Swarna bhasma
preparations are insignificant indicating that these preparations do not induce any complement activation when it reaches the systemic circulation.
Pharmacological effects exerted by the therapeutic agents depend upon its ability to cross the biological membranes into the systemic circulation and reach the site of action. This is usually occurred by one of the two pathways; paracellular or transcellular. Most drugs are transported transcellularly depending on their physicochemical properties; however, the paracellular route is usually the main route of absorption for nanoparticles. This is governed by the tight junctions (TJs). TJs are a multiple unit structure composed of multiprotein complex that affiliates with the underlying apical actomyosin ring. TJ proteins identified include transmembrane proteins; occludin and claudin, and cytoplasmic plaque proteins; ZO-1, ZO-2, ZO-3, cingulin, and 7H6. Although the adaptive mechanisms and specific regulation of these tight junctions are areas of active investigation and remain incompletely understood, it is known that some polymers can promote their widening, facilitating absorption of the particles into the systemic circulation. It has been established in this study by the tight junction visualization studies that the Swarna bhasma particles are capable of opening tight junctions, thus facilitating the bhasma particles to be absorbed into the systemic circulation and comes in direct contact with blood. Thus the Swarma bhasma particles should be highly compatible with blood.