Social interactions and olfactory cues are required for contagious itch in mice.

The phenomenon of contagious itch, observed in both humans and rodents, remains a topic of ongoing debate concerning its modulators and underlying pathways. This study delves into the relationship between contagious itch and familiar olfactory cues, a non-visual factor contributing to this intriguing behavior. Our findings showed that contagious itch in observer mice occurs during physical interaction with the cagemate itch-demonstrator but not with a stranger demonstrator or in a non-physical encounter condition. Notably, itch-experienced observer mice displayed an increased contagious itch behavior, highlighting the relevance of itch-associated memory in this phenomenon. Furthermore, anosmic observer mice, whether itch-naïve or itch-experienced, displayed no contagious itch behavior. These results demonstrate that the familiar olfactory cues, specifically cagemate body odors, are required for contagious itch behaviors in mice. In line with these behavioral findings, our study reveals increased activity in brain regions associated with olfaction, emotion, and memory during contagious itch, including the olfactory bulb, the amygdala, the hypothalamus, and the hippocampus, with this activity diminished in anosmic mice. In conclusion, our study unveils the critical role of familiar olfactory cues in driving contagious itch in mice, shedding light on the interplay between social factors, sensory perception, and memory in this phenomenon.

Astaxanthin as an Anticancer Agent against Breast Cancer: An In Vivo and In Vitro Investigation.

AIM: This study aimed to investigate the antioxidant properties, cytotoxic activity, and apoptotic effects of astaxanthin (ASX) on genes and pathways involved in breast cancer in Balb/c mice models injected with the 4T1 cell line. BACKGROUND: ASX could inhibit some tumor progression by using in vivo and in vitro models. OBJECTIVE: The effect of ASX on breast cancer was not fully understood till now. METHOD: In an in vivo model, 4T1 cells-injected mice were administered with different concentrations of ASX (100 and 200 mg/kg), and histopathological evaluations were done using an optical microscope and the hematoxylin and eosin (H&E) staining. The real- time PCR investigated the expression levels of B-cell lymphoma 2-associated X (Bax), B-cell lymphoma 2 (Bcl-2), and Caspase 3 genes in mice treated with 100 and 200 mg/kg ASX. Also, the level of superoxide dismutase (SOD) and malondialdehyde (MDA) were examined in ASX-treated cancer mice. RESULTS: ASX (200 mg/kg) caused a significant reduction in the mitotic cell count of tumor tissues compared to ASX (100 mg/kg). The antiproliferative effects of different concentrations of ASX were shown based on the MTT results. The treatment of breast tumor mice with both concentrations of ASX, especially 200 mg/kg, elevated the expression of Caspase 3, Bax, and SOD enzyme levels and decreased Bcl-2 expression and MDA enzyme levels. CONCLUSION: ASX can be considered a promising alternative treatment for breast cancer.

Losartan ointment attenuates imiquimod-induced psoriasis-like inflammation.

BACKGROUND: Psoriasis is a chronic skin condition associated with interleukin-23/interleukin-17 (IL-23/IL-17) pathway. Recent evidence declares that angiotensin II (Ang II) induces a potent IL-17-related inflammation. Meanwhile, Losartan, an angiotensin one receptor (AT1R) antagonist, attenuates the TH17-related responses. Therefore, we investigated the possible beneficial effects of topically applied Losartan1% ointment on imiquimod (IMQ)-induced psoriasis in mice. METHOD: Psoriasis was induced in mice consecutively for five days by topical IMQ on the shaved back. The IMQ-induced psoriasis was treated via topical administration of Losartan1% twice a day. The severity of skin inflammation was evaluated employing Psoriasis Area and Severity Index (PASI) scores. Subsequently, the skin samples were assessed using Baker's scoring system, stereological studies, and biochemical assessment with real-time PCR and immunohistochemistry. RESULTS: IMQ administration induced plaque-type psoriasis and skin inflammation. We characterized psoriatic lesions by hyperkeratosis, Munro abscess, rete ridges, and marked T-cell infiltrates. IMQ significantly increased epidermal volume, mRNA expression of IL-17a, IL-23, Ang II, AT1R, and TNF-α levels compared with the Placebo group. Topical administration of Losartan1% on IMQ-induced psoriasis significantly reduced the PASI scores and alleviated the erythema and scaling. The treatment significantly decreased the psoriatic thickness and dermal T-cell infiltration. Regarding biochemical assessment, Losartan1% considerably reduced the IMQ-induced increase of IL-17a, Ang II, and AT1R expression in the skin. CONCLUSION: Topical Losartan1% significantly alleviates psoriasis by reducing AT1R and IL-17a expression. Our results introduce AT1Rs as a promising therapeutic target in psoriasis and represent a link between angiotensin and TH17-related inflammation. However, the effects of AngII-AT1R systems on IL-17 signaling need to be confirmed by further investigations.