The anti-inflammatory activity of bentonites

Bentonites, naturally occurring clays, are produced industrially because of their adsorbent capacity but little is known about their effects on human health. This manuscript reports on the anti-inflammatory activity of bentonites. Bentonites collected from India (Bent-India), Hungary (Bent-Hungary), Argentina (Bent-Argentina), and Indonesia (Bent-Indonesia) were studied. All four bentonites were tested for anti-inflammatory activity using the mouse ear edema and the 12-O-tetradecanoylphorbol-13-acetate (TPA) method. Bentonites inhibited edema after 4 h (EI %), regardless of composition. A direct comparison between EI and surface area values showed that Bent-Argentina was four times more active than the other bentonites, with infiltration preferred in the former case. We attributed the inhibition of edema by bentonites to clay swelling, causing physical occlusion thereby limiting the movement of leukocyte cells towards the inflammation site. Expandability over changes in mineral composition underpinned inhibition of edema by bentonites, while evidence lacked to support chemical-transfer mechanism(s).