Inhibition of Intestinal Cholesterol Absorption by Ocimum sanctum L. Flower Aqueous Extract via Changing Physicochemical Properties of Cholesterol Micelles

Hyperlipidemia is recognized as a major contributor to chronic noncommunicable diseases. The primary strategy regarding hyperlipidemia prevention is involved in the blockade of intestinal cholesterol absorption. Ezetimibe (Eze) is the sole prescribed drug that targets Niemann‐Pick C1 Like 1 (NPC1L1), a key cholesterol transporter, resulting in reduced cholesterol levels. Nonetheless, several adverse effects have been reported, including headache, diarrhea, and cold‐like symptoms. Thus, complementary and alternative intervention exerting antihyperlipidemia while ensuring safety is a challenging option. Previously, leaves of Ocimum sanctum L., commonly known as holy basil, have been shown to lower plasma lipid levels in both humans and animals with hypercholesterolemia. However, the beneficial effects of O. sanctum L. flowers and the mechanisms of action have not been investigated yet. Herein, we first investigated the biological activity of O. sanctum L. flower aqueous extract (OSLY). This study neatly established a fast and robust screening methodology for investigating cholesterol absorption using fluorescent‐25‐NBD‐cholesterol incorporated by micelles (25‐NBD‐mc), followed by high‐content imaging analysis detection in Caco‐2 cells. Changes of physicochemical properties of cholesterol micelles by OSLY were addressed. The experimental findings demonstrated that 25‐NBD‐mc successfully mimicked NPC1L1‐mediated dietary cholesterol absorption into Caco‐2 cells. In addition, OSLY inhibited 25‐NBD‐mc uptake without cytotoxicity, similar to the positive drug Eze. Correspondingly, OSLY increased cholesterol micellar size and bile acid–binding capacity. Furthermore, like Eze, OSLY markedly reduced intestinal [ 3 H]‐cholesterol absorption compared to control in rat jejunal epithelial cells. Nonetheless, OSLY induced the gene expression of LXRα and PPARα, the regulator for downregulating NPC1L1, but not their activities, suggesting that OSLY inhibited the cholesterol absorption–mediated LXRα/PPARα‐independent pathway. In summary, OSLY exhibits a lipid‐lowering effect by reducing cholesterol absorption through interfering with the physicochemical properties of intestinal cholesterol micelles. As a result, OSLY is a promising alternative nutraceutical product aimed to prevent individuals with hyperlipidemia.