formononetin

Formononetin is a phytoestrogen that exhibits antioxidant, analgesic, anxiolytic, and anti-inflammatory properties. However, there is limited information about the central molecular mechanisms mediating the analgesic effects of formononetin.

The present study aimed to assess the impacts of formononetin on hypothalamic mRNA levels of hypocretin ( HCRT ), corticotropin-releasing hormone ( CRH ), and melanin-concentrating hormone ( MCH ).

Twenty male Wistar rats weighing 200 ± 10 g were divided into four groups (n = 5). Groups 1 and 2 were the control and the pain model groups, respectively, which received saline. Groups 3, 4, and 5 were the pain model rats that received 20 and 40 µg of formononetin and 20 µg of diclofenac via the third cerebral ventricle, respectively. To induce pain, formalin (50 µL of 5%) was injected into the plantar surface of the hind paw subcutaneously. Behavioral tests were performed. Hypothalamic samples were removed, and gene expression was measured using the real-time polymerase chain reaction (RT-PCR) method.

Formalin-induced pain caused a significant increase in the mRNA levels of HCRT, CRH, and MCH compared to the control. Administration of 20 and 40 µg of formononetin significantly decreased the mRNA levels of HCRT , CRH , and MCH in comparison to the formalin group.

Downregulation of hypothalamic CRH and blocking the effects of neuropeptide orexin and MCH signaling pathways upstream of CRH neurons may mediate the antinociceptive effects of formononetin.

Overexpression of (myeloid leukemia cell differentiation protein 1) Mcl-1 is associated with the reduction of ABT-737 toxicity and secondary resistance. In this study, the effect of formononetin (biochanin B) on Mcl-1 expression, cell growth, apoptosis and ABT-737 sensitivity of the acute lymphoblastic leukemia (ALL) cells was investigated. In this experimental study, the cell proliferation and MTT assays were used to investigate the effect of formononetin on cell growth and survival. qRT-PCR was performed for the measurement of gene expression. Hoechst 33342 staining and caspase-3 activity assay were used for the determination of apoptosis. Our data showed that formononetin and ABT-737 both led to a significant reduction in the IC50 value and synergistically reduced the cell growth and survival relative to single treatment. Overexpression of Mcl-1 was found after the treatment with ABT-737. Formononetin decreased the expression of B-cell lymphoma 2 (Bcl-2) and Mcl-1 and increased the Bcl-2-associated protein x (Bax) and P21 expression. Moreover, formononetin enhanced the apoptotic effect of ABT-737 in ALL cells. In summary, formononetin showed anti-carcinogenic activities in human ALL cells via suppression of cell growth and survival. Formononetin enhanced the apoptotic effect of ABT-737, with contribution by inhibition of the Mcl-1 expression.

Stress is an aversive stimulus that disrupts the organism's biological balance. Formononetin, an isoflavone, has been implicated in anxiolytic responses. However, the intra-hypothalamic molecular mechanisms by which formononetin controls stress remain unknown.

This study aimed to investigate the impact of formononetin on hypothalamic Mch and Crh gene expression in a rat model of stress.

Male Wistar rats (200 - 220 g) were used. Thirty minutes before exposure to stress, the rats were injected with either saline or formononetin. Two hours after stress induction, hypothalamic samples were dissected and stored at -70°C until the measurement of Mch and Crh gene expression using real-time PCR.

Stress induction led to a significant increase in Mch and Crh mRNA levels. However, animals receiving formononetin showed a significant reduction in Mch and Crh mRNA levels compared to the stressed rats.

Formononetin may exert anxiolytic effects by down-regulating intra-hypothalamic CRH and MCH signaling pathways.

Enhanced cell survival and drug resistance in tumor cells have been linked to the overexpression of antiapoptotic members of the Bcl-2 family proteins, including Bcl-2 and Mcl-1. The aim of this study was to explore the impact of formononetin and dihydroartemisinin combination on the growth and apoptosis of acute myeloid leukemia (AML) cells.

In this experimental study, the cell survival and cell proliferation were tested by MTT assay and trypan blue staining. The evaluation of cell apoptosis was conducted using Hoechst 33342 staining and a colorimetric assay to measure caspase-3 activity. To determine the mRNA levels of Mcl-1, Bcl-2, Bax, and Cyclin D1, a quantitative real-time polymerase chain reaction (qRT-PCR) was performed.

We showed that treatment with either formononetin or dihydroartemisinin alone, led to significant decrease in the cell survival and growth, and triggered apoptosis in U937 and KG-1 AML cell lines. Moreover, treatment with each of the compounds alone significantly decreased the mRNA levels of Mcl-1, Bcl-2 and Cyclin D1 mRNA, while, the expression level of Bax mRNA was enhanced. Combination of two compounds showed a synergistic anti-cancer effect.

The anti-leukemic potential of formononetin and dihydroartemisinin is exerted through the effect on cell cycle progression and intrinsic pathway of apoptosis. Therefore, they can be considered as a potential anti-leukemic agent alone or along with existing chemotherapeutic drugs.