Evaluation of Khat (Catha edulis) Use as a Risk Factor of Cancer: A Systematic Review

Spatiotemporal Distribution, Time to Treatment Outcome Clustering and Determinants of Esophageal Cancer in Ethiopia, a Scoping Study

INTRODUCTION

Esophageal cancer was the eighth and sixth leading cause of morbidity of all cancers in the world, and the 15th and 12th in Ethiopia, respectively. There is a lack of comprehensive data regarding Ethiopia's esophageal cancer hotspot, treatment outcome clustering, and other factors.

OBJECTIVE

This scoping review was designed to understand the extent and type of existing evidence regarding spatiotemporal distribution, time to treatment outcome clustering, and determinants of esophageal cancer in Ethiopia up to March 28, 2023.

METHODS

Three-step search strategies were employed for the scoping review from March 15 to 28, 2023. Targeted databases included PubMed/Medline, PubMed Central (PMC), Google Scholar, Hinari, and Cochrane for published studies and different websites for unpublished studies for evidence synthesis. Data were extracted using the Joanna Briggs Institute (JBI) manual format.

RESULTS

Our final analysis comprised 17 (16 quantitative and 1 qualitative) studies. Three studies attempted to depict the country's temporal distribution, whereas 12 studies showed the spatial distribution of esophageal cancer by proportion. The regional state of Oromia recorded a high percentage of cases. Numerous risk factors linked to the tumor have been identified in 8 investigations. Similarly, 5 studies went into detail regarding the likelihood of survival and the factors that contribute to malignancy, while 2 studies covered the results of disease-related treatments.

CONCLUSIONS

The substantial body of data that underpins this finding supports the fact that esophageal cancer has several risk factors and that its prevalence varies greatly across the country and among regions. Surgery, radiotherapy, or chemotherapy helped the patient live longer. However, no research has investigated which treatment is best for boosting patient survival and survival clustering. Therefore, research with robust models for regional distribution, clustering of time to treatment outcomes, and drivers of esophageal cancer will be needed.

Risk factors of oesophageal cancer at health facilities in Addis Ababa, Ethiopia: Unmatched case control study

Background

Oesophageal carcinoma is one of the most common cancers in Ethiopia. Its occurrences vary among regional states of the country. The identification of local risk factors of oesophageal cancer will make it simple to design a focused intervention. On local risk factors, there is, however, a shortage of empirical evidence. Therefore, the aim of study was to identify local risk factors.

Methods

An unmatched case control study design was employed. From February 2019 to August 2020, 338 histologically confirmed cases and 338 controls were recruited consecutively from six health facilities in Addis Ababa, Ethiopia’s capital city. To collect data from the cases and the controls, face to face interviews were conducted. Epi-info version 7 was used to enter and cleaned data, and SPSS version 23 was used to analyze it. The odds ratio was calculated based on hierarchal model multivariable logistic regression, and statistically significance was declared at p-value of <0.05.

Results

The mean (SD) age of the cases and the controls was 54.3 ± 12.5 years old and 40.2 ± 13.7 years old, respectively. The odds of oesophageal cancer was significantly higher among older ages (OR =11.0, 95% CI [6.60, 20.91]), rural residents (OR = 4.2, 95% CI [1.04, 16.80]), and those who had history of smoking (OR =1.3, 95% CI [1.12, 1.60]), khat chewing (OR = 4.0, 95% CI [2.50, 6.60]), raw meat consumers (OR = 2.6, 95% CI [1.75, 3.90]). Increasing monthly income (OR = 0.2, CI 95% [0.09, 0.49]) and a habit of eating fruits or vegetables (OR = 0.49, 95% CI [0.32, 0.76]) were associated with lower risks.

Conclusions

Tobacco smoking, khat chewing, age, residency, and red raw meat consumption were discovered to be positive predictors of oesophageal cancer, whereas fruit or vegetable consumption and higher monthly income were discovered to be inversely associated. It is advised to avoid the use of khat and tobacco, as well as to avail fruits and vegetables in dish.

Unraveling the Catha edulis Extract Effects on the Cellular and Molecular Signaling in SKOV3 Cells

Khat (Catha edulis (Vahl) Endl.) is an evergreen flowering shrub used as a stimulant in many regions worldwide including East Africa, the Arabian Peninsula, Europe, and the United States. Chewing leaves of khat induces excitement and euphoria, which are primarily attributed to two major constituents, cathinone and cathine. Khat also contains other important constituents such as cathedulins. A considerable number of studies reported side effects induced by the khat extracts to both embryos and adults. These include teratogenicity and developmental retardation, oral cancer and ulcers, high blood pressure, and myocardial infarction. So far, little attention has been paid to the effects of khat extracts on the molecular signaling interactions. We aimed in this study to investigate this through evaluating the effects of khat extracts on SKOV3, a human ovarian adenocarcinoma cell line. We show, by in vitro assays, that khat induces several cellular defects including reduced cell size, cell membrane damage, and apoptosis. At high khat extract concentrations, the cell metabolic activity, cell cycle, and cellular proliferation were affected. RT-qPCR analysis showed an increase in the gene expression of the apoptotic marker BAX, the tumor suppressor p53, and the inflammatory cytokine IL-6. Protein expression analysis by immunostaining showed downregulation of β-catenin, E-cadherin, and Ki-67 and upregulation of FZD8 and SPRY2, suggesting that Wnt and FGF signaling were implicated. SwissTargetPrediction in silico analysis showed that khat constituents cathine, cathinone, catheduline K2, and catheduline E5 bind to family A G-protein-coupled receptor, cause many neurological diseases and disorders such as Alzheimer's, schizophrenia, depression, and anxiety, and induce many ovarian cancer-related diseases. The analysis also showed that important signaling pathways such as CREB, Wnt, FGF, IL-6, and ERK/MAPK, and that of the endometrial cancer, and cell cycle were implicated. Upstream regulators of cathine and cathinone were found to potentially target several molecules including interleukin-8, MMP2, PLAU, and micro-RNAs. In conclusion, khat induces significant cellular and molecular changes that could potentially cause a wide range of serious diseases and syndromes. Such an impact could have a heavy burden on the health care system in the countries where khat is consumed.