Potential of natural products in osteosarcoma treatment: Focus on molecular mechanisms.

Osteosarcoma is the most frequent type of bone cancer found in children and adolescents, and commonly arises in the metaphyseal region of tubular long bones. Standard therapeutic approaches, such as surgery, chemotherapy, and radiation therapy, are used in the management of osteosarcoma. In recent years, the mortality rate of osteosarcoma has decreased due to advances in treatment methods. Today, the scientific community is investigating the use of different naturally derived active principles against various types of cancer. Natural bioactive compounds can function against cancer cells in two ways. Firstly they can act as classical cytotoxic compounds by non-specifically affecting macromolecules, such as DNA, enzymes, and microtubules, which are also expressed in normal proliferating cells, but to a greater extent by cancer cells. Secondly, they can act against oncogenic signal transduction pathways, many of which are activated in cancer cells. Some bioactive plant-derived agents are gaining increasing attention because of their anti-cancer properties. Moreover, some naturally-derived compounds can significantly promote the effectiveness of standard chemotherapy drugs, and in certain cases are able to ameliorate drug-induced adverse effects caused by chemotherapy. In the present review we summarize the effects of various naturally-occurring bioactive compounds against osteosarcoma.

The Role of Hydroxychloroquine in COVID-19: A Systematic Review and Meta-Analysis.

OBJECTIVE: A systematic review and meta-analysis was carried out to examine the role of hydroxychloroquine (HCQ) in the treatment of COVID-19. METHODS: We performed a systematic search in PubMed, Scopus, Embase, CochraneLibrary, Web of Science, Google Scholar, and medRxiv pre-print databases using available MeSH terms for COVID-19 and hydroxychloroquine. Data from all studies that focused on the effectiveness of HCQ with or without the addition of azithromycin (AZM) in confirmed COVID-19 patients, which were published up to 12 September 2020, were collated for analysis using CMA v.2.2.064. RESULTS: Our systematic review retrieved 41 studies. Among these, 37 studies including 45,913 participants fulfilled the criteria for subsequent meta-analysis. The data showed no significant difference in treatment efficacy between the HCQ and control groups (RR: 1.02, 95% CI, 0.81-1.27). Combination of HCQ with AZM also did not lead to improved treatment outcomes (RR: 1.26, 95% CI, 0.91-1.74). Furthermore, the mortality difference was not significant, neither in HCQ treatment group (RR: 0.86, 95% CI, 0.71-1.03) nor in HCQ plus AZM treatment group (RR: 1.28, 95% CI, 0.76-2.14) in comparison to controls. Meta-regression analysis showed that age was the factor that significantly affected mortality (P<0.00001). CONCLUSION: The meta-analysis found that there was no clinical benefit of using either HCQ by itself or in combination with AZM for the treatment of COVID-19 patients. Hence, it may be prudent for clinicians and researchers to focus on other therapeutic options that may show greater promise in this disease.