Anti-sickling efficacy and safety of Sailin-HbS, an indigenous Ayurvedic formulation

Sickle Cell Disease (SCD) is a hereditary condition characterized by a mutation in globin chains of hemoglobin. Polymerization of deoxygenated sickle hemoglobin (HbS) leads to rigid sickle shaped red blood cells (RBC), the primary cause of SCD pathobiology and multiple comorbidities including organ damage and pain. Gene therapy is the only treatment to reduce sickling, but its limitations including high cost, advanced technical resources and age limit pose a major challenge in its application. We examined the potential of a nutraceutical Sailin-HbS, formulated from the extract of 5 different plant sources with anti-oxidant and anti-inflammatory property, to ameliorate RBC sickling. Using sickle RBCs from individuals with SCD (SS-RBCs), Sailin-HbS demonstrated ∼74 % inhibition of sickling under low oxygen conditions; and significantly inhibited hypoxia-induced HbS polymerization by reducing polymerization kinetics at 700 nm. Osmotic fragility tests demonstrated enhanced resistance of SS-RBCs to osmotic stress in the presence of Sailin-HbS. We compared the anti-sickling effect of Sailin-HbS with known anti-sickling agents, Niprisan, SCD 101, AES-103/5-HMF and GBT440/Voxelotor, and found it to be equally and/or more effective. We tested the safety/toxicity of Sailin-HbS in 2 rodent models which showed a high safety threshold, with an oral LD50 exceeding 2000 mg/kg, placing it within the OECD-GHS category class 5. Sub-acute and chronic toxicity assessments in rats reveal no adverse effects on organ function or body weight, biochemical parameters, or complete blood counts, demonstrating its safety profile with established threshold levels. Thus, Sailin-HbS exhibits considerable anti-sickling efficacy without inducing toxicity, suggesting its translational potential in SCD.