Management of peripheral arterial disease of the lower extremities

Chrysin promotes angiogenesis in rat hindlimb ischemia: Impact on PI3K/Akt/mTOR signaling pathway and autophagy

Limb ischemia occurs due to obstruction of blood perfusion to lower limbs, a manifestation that is associated with peripheral artery disease (PAD). Angiogenesis is important for adequate oxygen delivery. The present study investigated a potential role for chrysin, a naturally occurring flavonoid, in promoting angiogenesis in hindlimb ischemia (HLI) rat model. Rats were allocated into four groups: (1) sham-operated control, (2) HLI: subjected to unilateral femoral artery ligation, (3) HLI + chrysin: received 100 mg/kg, i.p. chrysin immediately after HLI, and (4) HLI + chrysin + rapamycin: received 6 mg/kg/day rapamycin i.p. for 5 days then subjected to HLI and dosed with 100 mg/kg chrysin, i.p. Rats were killed 18 h later and gastrocnemius muscles were collected and divided into parts for (1) immunohistochemistry detection of CD31 and CD105, (2) qRT-PCR analysis of eNOS and VEGFR2, (3) colorimetric analysis of NO, (4) ELISA estimation of TGF-β, VEGF, ATG5 and Beclin-1, and (5) Western blot analysis of p-PI3K, PI3K, p-Akt, Akt, p-mTOR, mTOR, and HIF-1α. Chrysin significantly enhanced microvessels growth in HLI muscles as indicated by increased CD31 and CD105 levels and decreased TGF-β. Chrysin's proangiogenic effect is potentially mediated by increased VEGF, VEGFR2 and activation of PI3K/AKT/mTOR pathway, which promoted eNOS and NO levels as it was reversed by the mTOR inhibitor, rapamycin. Chrysin also inhibited autophagy as it decreased ATG5 and Beclin-1. The current study shows that chrysin possesses a proangiogenic effect in HLI rats and might be useful in patients with PAD.

An Overview of Peripheral Artery Disease in the Elderly: A Study in a Tertiary Hospital Southern Nigeria

BACKGROUND

The incidence of Peripheral Artery Disease (PAD), one of the manifestations of atherosclerosis, is increasing worldwide with significant effects on the quality of life. The disease is a strong prognostic marker for future cardiovascular events in people over 60 years, but relatively little is known about the condition among the elderly in sub-Saharan Africa.

OBJECTIVE

The objective of this study was to determine the prevalence and pattern of peripheral artery disease in elderly patients. Materials and Methods: A cross-sectional hospital-based study was carried out among elderly patients aged 60 years and above attending the Geriatric Clinic of the Department of Family Medicine of University of Benin Teaching Hospital, Edo State, Nigeria, from September to November 2017. Using systematic random sampling technique, 370 respondents were recruited from a sampling frame of 2160 respondents and a sampling fraction of 6. A structured questionnaire was administered to collect data on sociodemographic characteristics, lifestyle variable, and medical history. The ankle-brachial index (ABI) and toe-brachial index (TBI) were used to assess for PAD. The analysis was done using descriptive statistics.

RESULTS

The mean age was 69.3 ± 7 years comprising 76.5% females, 50% of the respondents were married, while 47% were widowed. The ABI showed 35.4% prevalence of PAD, while TBI for respondents with elevated ABI was 45.0%.

CONCLUSION

The study showed a point prevalence of PAD to be 37.8%. From the total respondents, 45.7% had mild, while 2.9% had severe PAD. Routine screening for PAD is recommended for the early detection and management.

Curcumin Ameliorates Ischemia-Induced Limb Injury Through Immunomodulation

Background

The prevalence of peripheral arterial disease (PAD) is increasing worldwide. Currently, there is no effective treatment for PAD. Curcumin is an ingredient of turmeric that has antioxidant, anti-inflammation, and anticancer properties. In the present study we investigated the potential effect of curcumin in protecting against ischemic limb injury.

Material/Methods

We used an established hindlimb ischemia mouse model in our study. Curcumin was administrated through intraperitoneal (I.P.) injection. Immunohistochemical staining and ELISA assays were performed. Treadmill training was used to evaluate skeletal muscle functions of animals.

Results

Our experiments using in vivo treadmill training showed that curcumin treatment improved the running capacity of animals after ischemic injury. Histological analysis revealed that curcumin treatment significantly reduced the skeletal muscle damage and fibrosis associated with ischemic injury. In order to determine the cellular and molecular mechanisms underlying curcumin-mediated tissue protection, immunohistochemical staining and ELISA assays were performed. The results showed that curcumin treatment led to less macrophage infiltration and less local inflammatory responses as demonstrated by decreasing TNF-α, IL-1, and IL-6 levels. Further immunofluorescent staining of tissue slides indicated that curcumin treatment inhibited the NF-κB signaling pathway. Finally, curcumin can inhibit NF-κB activation induced by LPS in macrophages.

Conclusions

Our study results show that curcumin treatment can ameliorate hindlimb injury following ischemic surgery, which suggests that curcumin could be used for PAD treatment.

Transplantation of placenta-derived mesenchymal stem cells enhances angiogenesis after ischemic limb injury in mice

Mesenchymal stem cell‐based therapy has emerged as a promising approach for the treatment of peripheral arterial disease. The purpose of this study was to examine the potential effects of human placenta‐derived mesenchymal stem cells (PMSCs) on mouse hindlimb ischemia. PMSCs were isolated from human placenta tissue and characterized by flow cytometry. An in vivo surgical ligation‐induced murine limb ischemia model was generated with fluorescent dye (CM‐DiI) labelled PMSCs delivered via intramuscular injection. Our data show that PMSCs treatment significantly enhanced microvessel density, improved blood perfusion and diminished pathologies in ischemic mouse hindlimbs as compared to those in the control group. Further immunostaining studies suggested that injected PMSCs can incorporate into the vasculature and differentiate into endothelial and smooth muscle cells to enhance angiogenesis in ischemic hind limbs. This may in part explain the beneficial effects of PMSCs treatment. Taken together, we found that PMSCs treatment might be an effective treatment modality for treatment of ischemia‐induced injury to mouse hind limbs by enhancement of angiogenesis.

Exercícios físicos na doença arterial obstrutiva periférica

A maioria dos pacientes portadores de claudicação intermitente, um aspecto clínico da doença arterial periférica, tem importante limitação nas atividades físicas e redução na qualidade de vida. O objetivo deste estudo foi realizar uma revisão da literatura sobre a intervenção através de exercícios em portadores de doença arterial obstrutiva periférica com claudicação intermitente. Trata-se de uma revisão de artigos científicos consultados nos bancos de dados da BIREME, PubMed e SciELO, através das fontes LILACS e MEDLINE e a partir dos descritores em Ciências da Saúde claudicação intermitente, doenças vasculares periféricas, reabilitação, exercício e terapia por exercício. Concluiu-se que, apesar da variabilidade dos regimes de caminhada identificados na literatura, o treino aeróbio, de uma forma geral, proporciona benefícios a pacientes portadores de doença arterial obstrutiva periférica com claudicação intermitente, principalmente na melhora do desempenho de caminhada, o que pode ter impacto significativo na qualidade de vida desses pacientes.