Effect of various stabilizing agents on Imperata cylindrica grass pollen allergen extract

Cylindrin from Imperata cylindrica inhibits M2 macrophage formation and attenuates renal fibrosis by downregulating the LXR-α/PI3K/AKT pathway

Imperata cylindrica, a medicinal plant used in Traditional Chinese Medicine, has been used to treat chronic kidney disease. Extracts of I. cylindrica display anti-inflammatory, immunomodulatory, and anti-fibrotic properties. However, the active components of the extracts and their protective mechanisms have not been fully elucidated. In this study, we explored the ability of cylindrin, the main active compound extracted from I. cylindrica, to protect against renal fibrosis and to investigate the potential mechanisms involved. At high doses, cylindrin exerted protective effects against folic acid-induced kidney fibrosis in mice. Bioinformatic analysis predicted the LXR-α/PI3K/AKT pathway as a target of regulation by cylindrin. This was supported by our in vitro and in vivo results showing that cylindrin significantly downregulated the expression of LXR-α and phosphorylated PI3K/AKT in M2 macrophages and mouse renal tissues. Furthermore, high-dose cylindrin inhibited M2 polarization of IL-4-stimulated macrophages in vitro. Our results suggest that cylindrin alleviates renal fibrosis by attenuating M2 macrophage polarization through inhibition of the PI3K/AKT pathway via downregulation of LXR-α.

Introducing a Stabilizer Formulation for Allergenic Mold Extracts

Background

Sensitization to common mold allergens is one of the major causes of allergic rhinitis and asthma. Therefore, there is a critical need for standard sensitivity tests including skin prick tests to improve the stability of fungi extracts in traditional allergenic formulations. To address this concern, the present study aimed to develop a formulation to preserve allergenic activity of mold extracts.

Methods

48 stabilizer formulations were designed and monitored for allergenic activity during a 40-days incubation period at 37 °C using an ELISA. Specifically, the IgE reactivity of allergenic A. alternata extracts were examined. After establishing the most effective stabilizer formulation, we evaluated whether it could protect the allergenic activity of Alt a1, A. fumigatus, and C. herbarum using an IgE inhibition ELISA after 40 days at 37 °C.

Results

We demonstrated that the most effective stabilizer formulation was a glycerol-based extract containing Arg and Glu. This formulation had an equal ratio of sucrose, sorbitol and protein and was able to preserve more than 95% of allergenic A. alternata extract activity during a 40-days incubation period at 37 °C.

Conclusion

The present study reveals a novel formulation that is an efficient stabilizer of allergenic mold extract activity and has practical applications in mold skin prick tests, ELISAs, immunotherapies, and RAST.

Stability of protease-rich periplaneta Americana allergen extract during storage: formulating preservatives to enhance shelf life

Allergenic proteins in extracts degrade rapidly and lose potency on storage. Hence, formulation of optimum conditions is required to enhance shelf life of extracts for proper allergy diagnosis and immunotherapy. In the present study, allergenic potency of P. americana proteins was evaluated after storage with epsilon-aminocaproic acid (EACA), sucrose, glycerol, pepstatin A, and aprotinin, individually for 1, 3, 6, and 12 months at 4, 25, and 37 degrees C. P. americana extract stored with EACA and sucrose individually retained potency comparable to proteins in standard extract (freeze-dried extract, stored at-70 degrees C) upto 6 months at 4 degrees C. The extracts without preservatives or with glycerol, pepstatin A, aprotinin, or stored at 37/25 degrees C were severely degraded and lost potency by 3 months. A formulation containing a combination of EACA and sucrose enhanced the shelf life of P. americana proteins upto 12 months at 4 degrees C. Hence, EACA and sucrose together show better potential for stabilization of protease-rich extracts.