Phenolic profile, antioxidant and enzyme inhibitory activities of underutilized spices from Central Africa.

The aim of the present study is to evaluate phytochemical profile, antioxidant and enzyme inhibitory activity of some underutilized Cameroon spice extracts, viz. The fruit of Xylopia africana, the fruit and the bulb of Aframomum sulcatum; and the bark of Hypodaphnis zenkeri. Four different solvent combinations were used for extraction of phytochemicals. Highest total polyphenol, flavonoid and tannin contents were observed in X. africana extract 10.32 ± 0.49 g gallic acid eq/100 g of dry matter, 146.66 ± 4.15 mg quercetin eq/100 g of dry matter, 452.44 ± 2.7 mg tannic acid eq/100 g spices dry matter. Methanol extracts revealed the presence of chlorogenic acid (0.790-4.312), vanillic acid (0.830-19.768), epicatechin (25.386-34.707), p-coumaric acid (1.127-12.652), protosynapic acid (0.221-186.562) and T-cinnamic acid (3.794-52.58) mg/100 g dry spice by HPLC analysis. Extracts of X. africana and H. zenkeri exhibited higher antioxidant activity: DPPH (182.24 ± 2.41 mg ascorbic acid eq/g dry spice), ABTS (9.247 ± 0.004 g trolox eq/100 g spice), hydroxyl free radicals (729.27 ± 3.07 mg mannitol eq/100 g spice) and reducing power (2.351 ± 0.002 g ascorbic acid equivalent/100 g spice). Positive and high correlations existed between the antioxidant activity of extracts obtained with different methods and their corresponding phenolic content. Extract of A. sulcatum highly inhibited porcine pancreatic lipase whereas, X. africana and H. zenkeri extracts highly inhibited α-amylase (98.82 and 99.54% respectively). These spices could be utilized as natural antioxidant sources for the management oxidative stress, lipid and carbohydrate metabolism related diseases.

Evaluation of hepatic fibrosis in HIV/HCV co-infected individuals in Yaoundé, Cameroon: usefulness of APRI score in resource-constrained settings.

BACKGROUND: HIV infection exacerbates the prognosis of HCV infection, with a faster progression of hepatitis. Hepatic fibrosis is the major disruption of the hepatic tissue architecture characterized by anarchic deposition and excess of the extracellular matrix. The objective of this study was to evaluate hepatic fibrosis in HIV/HCV co-infected individuals as compared to HCV mono-infected. METHODS: A total of 97 participants (mean age 60.2 ± 14.3 years and 0.76 male/female sex ratio) was enrolled in a study conducted in Yaoundé, Cameroon from November 2018 to January 2019. Liver fibrosis was assessed by the APRI score (Aspartate Aminotransferase or AST/Platelet Ratio Index) which identifies the stage of fibrosis as classified by the Metavir system (F0 to F4). CD4 counts and plasmatic HIV viral load of HIV/HCV co-infected individuals were determined and the correlation between hepatic fibrosis and immuno-virological status established. Statistical analysis was done using Microsoft Excel 2016 and EpiInfo7 software. RESULTS: A high proportion (63.6%) of HIV/HCV co-infected participants had an abnormal AST level: 73.6 ± 45.8 IU/L as compared to 58.5 ± 39.3 IU/L (59.3%) among HCV mono-infected participants. The frequency of thrombocytopenia was 63.6% with a mean platelet count of 137 ± 50 ×  103 IU/L in HIV/HCV co-infected participants as compared to 176 ± 67 × 103 IU/L in HCV mono-infected participants (38.4%). The progression of hepatic fibrosis in participants with clinically significant fibrosis: F2, F3 and F4 was higher among HIV/HCV co-infected and the mean APRI score was 1.7 ± 1.4 versus 1 ± 0.8 among HCV mono-infected (26.7%). All participants (100%) with detectable HIV viral load had clinically significant fibrosis compared to 33.4% in those with undetectable HIV viral load (p = 0.55). Only 42.9% participants with CD4 >  500 cells/µL had clinically significant fibrosis (p = 0.72) while 100% participants with CD4 <  200 cells/µL had clinically significant fibrosis (p = 0.58). CONCLUSIONS: A high level of AST combined with thrombocytopenia (APRI score > 1.5) is an indicator of hepatic fibrosis in HIV/HCV co-infected individuals. Because of its non-invasive and less costly nature, the APRI score can be a suitable biomarker to monitor hepatic fibrosis in HIV/HCV co-infected individuals in resource constrained settings.

Classification of Pepper Seeds by Machine Learning Using Color Filter Array Images.

The purpose of this work is to classify pepper seeds using color filter array (CFA) images. This study focused specifically on Penja pepper, which is found in the Litoral region of Cameroon and is a type of Piper nigrum. India and Brazil are the largest producers of this variety of pepper, although the production of Penja pepper is not as significant in terms of quantity compared to other major producers. However, it is still highly sought after and one of the most expensive types of pepper on the market. It can be difficult for humans to distinguish between different types of peppers based solely on the appearance of their seeds. To address this challenge, we collected 5618 samples of white and black Penja pepper and other varieties for classification using image processing and a supervised machine learning method. We extracted 18 attributes from the images and trained them in four different models. The most successful model was the support vector machine (SVM), which achieved an accuracy of 0.87, a precision of 0.874, a recall of 0.873, and an F1-score of 0.874.

Possibilities of valorization of Gnetum spp leaves in modern gastronomy: Production and characterization of new vegetable tarts and salads.

Gnetum spp is a green creeper plant abundantly found in the Central African forests. Their leaves are eaten as vegetable by inhabitants. In order to valorize this vegetable in modern gastronomy, a survey was carried out in three towns of Cameroon to evaluate its importance in the feeding habits. The leaves were also sliced in two different forms, precooked, spin-dried and used for Gnetum tarts and salads production. 50, 100 and 150 g of thin sliced precooked leaves were used to prepare three salads and three tarts, keeping the other ingredients constant. Three additional tarts were prepared similarly using thinnest sliced precooked leaves. The final products were analyzed in terms of physiochemical, nutritional and sensorial properties. More than 96.9% of people investigated eat Gnetum leafy vegetables at least once per month. The survey study indicates that the transformation of Gnetum is mostly done by people within the age of 20 to 40 years old. Results of the physicochemical analyses showed that the total protein, lipid and carbohydrate contents increased in general with the increasing of the Gnetum leaf quantities used for preparation. The crude fiber contents of salads and tarts ranged from 52.00 ± 0.68 to 62.66 ± 1.26 and 29.33 ± 0.67 to 33.66 ± 0.47 g/100 g DW respectively. They were positively correlated with the quantity of Gnetum leaves used. The total phenolic contents, also increased significantly (p < 0.05) with the quantity of Gnetum leaves, from 182.45 ± 1.69 to 493.52 ± 2.10 mg/100 g DW for the salad and from 86.69 ± 4.08 to 283.21 ± 6.79 mg/100 g DW for the tart. The calculated energy density of tarts and salads permitted to classify these food products as low and high energy density foods respectively. The nutritional densities of produced tarts oscillated from 0.27 to 0.3 and that of salads from 0.58 to 0.71. With their nutritional values and the significant amount of fibers, Gnetum tarts and salads could be good new recipes to valorize the Gnetum leafy vegetables.

Indigenous spices consumed in the food habits of the populations living in some countries of Sub-Saharan Africa: Utilisation value, nutritional and health potentials for the development of functional foods and drugs: A review.

This manuscript reviews the literature by giving a brief history of spices in general, how they played an important role in the past for the discovery of the world. The review paper gives the value of spices today then makes a difference between the group of spices on which it is focused (local, indigenous, less-known or under-utilised spices) and the conventional spices. The utilisation value of the spices by the populations is discussed as ethno-nutritional and ethnopharmacological uses, and scientific evidences from laboratory experimentations are reviewed to support some ethnopharmacological claims that are made on this plant materials, as well as their physicochemical composition. The review shows that less-known and under-utilised spices consumed in the food habits of population groups living in some Sub-Saharan African countries constitute an industrial opportunity for the development of modern food products, nutraceuticals and functional foods.

Ricinodendron heutelotii (Bail.) or Tetracarpidium conophorum Müll. oils fed to male rats lower blood lipids.

Ricinodendron heudelotii and Tetracarpidium conophorum (Euphorbiaceae family) are 2 oil-bearing wild plants whose fruits are generally consumed in Cameroon. T conophorum kernels are eaten as nibbles after cooking. Kernels of R heudelotii are used as spice in many dishes in Cameroon. Oil from T conophorum contains a high level of alpha-linolenic acid (72.24%), and oil from R heudelotii kernels is a good source of alpha-eleostearic acid (9c, 11t, 13t; 52.61%), which is a conjugated linolenic acid. Polyunsaturated fatty acids have received considerable interest because their consumption has been associated with beneficial health effects. We hypothesized that the consumption of R heudelotii and T conophorum oils would alter the in vivo lipid profiles and some antioxidants parameters. Therefore, male Sprague-Dawley rats (age, 1 month, n = 18) were fed with a standard, commercial diet (control group), or a diet containing T conophorum oil (TCO group) or R heudelotii oil (RHO group). After 60 days of feeding the respective diets, blood samples were collected and used to determine biochemical parameters. High-protein lipoprotein cholesterol, creatinine, alanine aminotransferase, alkaline phosphatase, total bilirubin, malondialdehyde, and selenium levels were not significantly different (P > .05) between the RHO and TCO groups. The atherogenicity index was higher for the group of rats fed a standard, commercial diet compared with the RHO and TCO groups. The oils examined in this study reduced cholesterol and triglyceride levels in rats compared with the control group fed the standard diet.