Plectranthus Esculentus Research Articles

Nutrient Composition, Antioxidant Capacity and Natural Products in Livingstone Potato (Plectranthus esculentus )

The nutrients, natural products and antioxidant capacity of flour from Livingstone potato (Plectranthus esculentus) tubers were investigated. The flour contained 8.26 ± 0.20% moisture, 2.58 ± 0.18% ash, 2.60 ± 0.07% dietary fiber, 5.30 ± 0.17% lipid, 7.87 ± 0.04% protein and 76.00 ± 2.33% carbohydrate, but contained low amount of thiamine, riboflavin and niacin. The total flavonoid content of flour was lower (P < 0.05) than its total phenolic content. The antioxidant assay of flour (determined using 2,2-diphenyl-1-picrylhydrazyl radical and reducing power assays) indicated its strong antioxidant activity, although lower than that of quercetin. Gas chromatographic mass spectrometric assay of methanol/chloroform extract of flour revealed the presence of 13 compounds, whereas the major compounds in the extract with identified biological properties were 9,12-octadecadienoic (55.31%), 12-methyl-E,E-2,13-octadecadien-1-ol (21.68%), 10-octadecenoic acid methyl ester (2.74%) and 3,5-di-t-butyl phenol (2.34%). Livingstone potato contains strong antioxidant activity and some bioactive compounds that support its biological properties. Practical Applications This paper reveals the bioactive principles/natural products in Livingstone potato that justify its biological properties as used in folklore medicine. By isolating and identifying some compounds with biological activities in this plant, new drugs could be developed from this plant in the future to treat various diseases.

In vitro-induced tetraploids of Plectranthus esculentus are nematode-tolerant and have enhanced nutritional value

Plectranthus esculentus (Family: Lamiaceae), or Livingstone potato, is an edible tuberous vegetable which originated in Africa, with central Africa being the centre of origin. P. esculentus is found throughout the continent, including the north-eastern regions of South Africa. Although the tubers are edible, limited crop improvement has been achieved; therefore, a study comprising in vitro polyploidisation was carried out with subsequent evaluation of plant nutritional value and nematode tolerance of the induced tetraploids compared with the diploid controls. Tetraploid tubers had a higher starch content compared with the diploids, however there was no significant difference in mineral element content for either the leaves or the tubers when induced tetraploids were compared with the diploid control. Further, induced tetraploids appeared to be significantly more tolerant to rootknot nematode, Meloidogyne spp., than the diploids. A significantly higher number of egg masses per root system and number of eggs and J2 (juvenile stage 2) individuals per root system were detected in control plants, compared with tetraploid plants. Induced tetraploidy resulted in plants with a higher nutritional starch concentration and tolerance to rootknot nematode, characteristics which will improve the cultivation and utilisation of the crop. Morphologically, tetraploid plants had fewer, thicker stems per plant compared with diploid plants.

A Survey of the Production Practices of Livingstone Potato (Plectranthus esculentus), an Indigenous and Underutilized Vegetable in Zimbabwe

Aims: The main objectives of the study were to establish the current production practices, constraints, and identity of the different landraces of Livingstone potato (Plectranthus esculentus) that are grown in Zimbabwe as well as the potential for improvement of the indigenous traditional vegetable in the small holder-farming sector. Study Design: A questionnaire based survey was conducted. Place and Duration of Study: The study was carried out in Makoni, Mutasa and Nyanga Districts (Manicaland Province) and Marondera District (Mashonaland East Province) of Zimbabwe, in April and December 2013. Original Research Article Kujeke et al.; JAERI, 4(4): 175-187, 2015; Article no.JAERI.2015.063 176 Methodology: A total of 103 respondents from three Districts representing 25% of the population of growers were selected randomly and interviewed. Results: Livingstone potato is a minor crop mainly grown for sale and food by women (97%). The 12 landraces still being cultivated were Ndurwe, Gombwe/a, Chibanda, Nziye, Sasamwi, Musande, Chizambezi, Nyabewu/Nyabuti, Nyatiya, Mutsaza, Chibhurandaya and Tutsenza. There are no improved varieties and growers retain seed (91.3%) from the previous crops. Production is mainly done on ridges in wetlands, (89.3%) as a sole crop (79.6%). However the current practices have not been evaluated. Production is on the decline and growers attributed this to poor rainfall (30.1%) and poor prices on the market (43.7%). There is evidence of loss of germplasm as indicated by the non-cultivation of some landrace. Results also showed that 97% of the respondents were interested in growing improved varieties from the local germplasm pool and from other countries. Conclusion: Livingstone potato is a neglected crop as current production practices have not been evaluated to optimize yields. Research on this minor crop needs to be carried out and the landraces available need to be maintained and improved.

Effect of Livingstone potato (Plectranthus esculentus N.E.Br) on hepatic glucose-6-phosphophate dehydrogenase activity of streptozotocin induced diabetic rats.

To determine the effect of Livingstone potato (Plectranthus esculentus N.E.Br) on hepatic G6PD in streptozotocin induced diabetic rats. The G6PD activities in the liver homogenates of the rats and chemical analysis of the test feeds were determined using standard techniques. The diabetic control rats had significant elevation (P < 0.05) of their hepatic G6PD activities compared with the non-diabetic rats. Intake of the test feed by the diabetic rats of group 3, resulted in significant (P<0.05) amelioration of their hepatic G6PD activities in comparison with the diabetic control rats. Chemical analysis of the test feed revealed that it contained considerable amounts of tannins, saponins, alkaloids, antioxidants and their cyanide contents were below the toxic level for humans. The study shows ameliorative potentials of Livingstone potato on the hepatic G6PD activity of diabetic rats which is attributed to its antioxidant/polyphenolic constituents.

Effect of Livingstone Potato (Plectranthus esculenthus N.E.Br) on Diabetes and Its Complications in Streptozotocin Induced Diabetes in Rats.

BackgroundThe effect of livingstone potato (Plectranthus esculenthus N.E.Br) on diabetes and its complications in Streptozotocin induced diabetic rats was investigated. The duration of the experiment was 4 weeks.MethodsThe blood glucose level of the rats was measured with a glucometer, the protein and glucose and specific gravity in the urine samples of the rats were measured using urine assay strips and urinometer respectively. The liver and kidney function parameters in the serum of the rats were determined using Biosystem Kits.ResultsThe diabetic rats given livingstonepotato incorporated feeds, had 129.7% decrease in their hyperglycemia with corresponding amelioration of their elevated urinary protein, sugars, specific gravity, renal growth, liver growth as well as 15.64% decrease in body weights compared with the nondiabetic rats that had 5.54% decrease in blood glucose and 20.39% increase in body weight unlike the diabetic control rats that had 18.34% decrease in blood glucose and 52.68% decrease in body weight. There were significant differences (P<0.05) in the relative liver, pancreas, and kidney weights of the diabetic rats given livingstone potato feeds compared with the diabetic control while there were no significant differences (P>0.05) in the relative heart weights of all the rats in the three different groups. In terms of liver and kidney function parameters, values obtained for the diabetic rats given livingstone potato incorporated feeds were not significantly different from that of the nondiabetic rats except for total bilurubin, aspartate transaminase, and creatinine (P>0.05) while they were significantly different from the values obtained for the diabetic control rats (P<0.05). In addition, the serum amylase of the diabetic control rats were significantly higher (P<0.05) than that of the nondiabetic and diabetic rats treated with livingstone potato incorporated feeds.ConclusionResults show the antidiabetic actions of livingstone potato and its ability to ameliorate glomerular complication and liver hypertrophy in diabetics.

Effect of livingstonepotato (Plectranthus esculenthus N.E.Br) on hyperglycemia, antioxidant activity and lipid metabolism of streptozotocin induced diabetic rats

The effect of livingstone potato (Plectranthus esculenthus N.E.Br) on serum glucose, glycated hemoglobin (HbA1C), serum triglyceride, total cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), very low density lipoprotein (VLDL), hepatic malic enzyme (ME), isocitrate dehydrogenase (IDH) and catalase activities of Streptozotocin induced diabetic rats were investigated using standard techniques. The atherogenic index (AI) and coronary risk index (CRI) of the rats were calculated as the ratios of LDL to HDL and total cholesterol to HDL, respectively. The serum glucose of the non-diabetic, diabetic control and diabetic rats given livingstone potato incorporated feeds (test feed) were 92.58 ± 3.97, 352.30 ± 4.88 and 165.50 ± 7.88 mg/dl, respectively. Intake of the test feed by the diabetic rats of group 3, resulted in significant (P < 0.05) decrease of their serum glucose, HbA1c, triglyceride, cholesterol, LDL, VLDL, AI and CRI but significant increase (P < 0.05) of hepatic levels of ME, IDH, catalase and serum HDL compared with the diabetic control rats that had significant alteration of these parameters (P < 0.05) compared with the non-diabetic rats. The feed intakes of the non-diabetic, diabetic control and diabetic rats given the test feed were 133.34 ± 1.32, 137.84 ± 5.77 and 146.38 ± 4.33 g/rat/week by the last week of experimentation. The diabetic control rats recorded significant loss of weight (P < 0.05) compared with the non diabetic rats despite increased feed intake. Chemical analysis of the standard and test feeds showed that the standard rat feed contained 15.00 ± 0.78% protein, 7.24 ± 1.20% fat, 31.55 ± 2.62% carbohydrates, energy value of 290.65 ± 4.77 kcal/100 g, 10% crude fiber and 0.12 ± 0.04 mg Gallic Acid Equivalent while the test feed contained 40.10 ± 0.16% carbohydrates, 17.22 ± 0.40% protein, 22.16 ± 0.34% fat, energy value of 428.70 ± 2.12 kcal/100 g, 8.51 ± 0.16% crude fiber, 1.3 ± 0.2 mg Gallic Acid Equivalent/g of sample and strong antioxidant activity comparable to standard quercetin. The study shows the potentials of livingstone potato in the management of diabetes and hyperlipidemia.

Morphology, physical, chemical, and functional properties of starches from cereals, legumes, and tubers cultivated in Africa: A review

AbstractIn Africa a variety of indigenous cereals, legumes, and tubers are cultivated as starchy food crops. These include sorghum, millet species including pearl millet, finger millet, teff, and white and black fonio, and African rice as cereals; cowpea, Bambara groundnut, African yambean and West African locust bean as legumes; and Zulu round potato and the Livingstone potato as tubers. Many of these plants are considered as “lost crops of Africa.” This paper critically reviews the literature on the physical, chemical, and functionality of their starches. Information is essentially limited to the native starches of sorghum, some millets, and cowpea. Livingstone potato starch information is essentially absent. Notable characteristics of African starches include that teff and finger millet have compound starch granules. Some of the starches have unique properties which could be valuable. The very small granular size of teff and its functional properties can be exploited as a fat replacer. The high retrogradation of cowpea starch has potential in gluten‐free pasta and noodles. Nonfood applications for the African starches should be considered in the growing mining and oil industries in Africa.

Growth Performance of Finisher Broilers on Livingstone-Potato (Plectranthus esculentus) Tubers Meal

A feeding trial lasting 42 days was conducted using seventy two (72) 4-weeks old Anak broiler chicks with an average initial live weight of 4.40 kg to determine the growth performance of finisher broilers fed diet containing Livingstone-potato tubers meal. The animals were assigned to four treatment based on their initial live weight. The diets were formulated to be isonitrogenous (20% CP). The control diet was based on maize and soybean meal without Livingstone-potato tubers meal. Feed and water were offered ad libitum. The growth performance of broilers fed on various levels of meals in which Livingstone-potato (Rizga) meal substituted maize at 10%, 20% and 30% showed that there were no significant differences (p 0.05) influenced by the dietary levels of Livingstone-potato (Plectranthus esculentus) meal. The results suggest that 30% replacement of maize with Livingstone-potato (Plectranthus esculentus) meal produced no negative effect on the production performance of finisher broilers.

Culinary and sensory characteristics of Hausa potato (Solenostemon rotundifolius) and Livingstone potato (Plectranthus esculentus) tubers in Nigeria

Presently, there is dearth of scientifically published information on the sensory and culinary characteristics of Hausa potato (Solenostemon rotundifolius) and Livingstone potato (Plectranthus esculentus). Therefore, matured tubers of these crops, harvested at National Root Crops Research Institute, Umudike, Abia State, Nigeria, were used to determine their fresh and cooked tuber characteristics. Results of the investigations showed that the thin skinned fresh tubers of both crops had cylindrical shape and weighed less than 100 g. The mean dry matter and starch contents of Hausa potato were 28.62 and 15.14% respectively, while the corresponding values for the Livingstone potato were 13.17 and 5.57%. The mealy boiled tubers and crispy salted French fries from the experimental tubers were found generally acceptable (as food) by semi trained sensory assessors. The use of these tuberous staples as potential sources of dietary fibre was also observed. Key words: Hausa potato, Livingstone potato, culinary characteristics, boiled tubers, French fries, Nigeria.

Survey of production, utilization and proximate composition of some minor rootand tuber crops in Nigeria

A survey was conducted between 2004 and 2005 to explore and collect germplasms of minor root and tuber crops grown in Nigeria. Information collected include, local names, locations, production/agronomic practices, utilization and marketing among others. Samples of materials collected were analyzed for their proximate compositions. A total of 76 turmeric, 19 Hausa potato, 13 Livingstone potato and 21 Polynesian arrowroot accessions were collected. Turmeric is cultivated and utilized in 19 states, Hausa potato 6 states, Livingstone potato two states while Polynesian arrowroot was collected from 10 states but utilized as food only in five states. The highest number of turmeric collection was obtained in Ekiti state (15.8%). While the highest collection of Hausa potato (36.8%) and Livingstone potato (69.2%) were obtained respectively from Kaduna and Plateau states, 19% of Polynesian arrowroot collections were each obtained in Plateau and Oyo states. Most of the crops are produced in smallholdings of less than 0.1 ha. Cultivation was mostly by old women except Polynesian arrowroot that was collected in the wild. The carbohydrate content (NFE) of the crops ranges between 60.23-80.40 g/100g, crude protein (7.58-14.00g/100g), total ash (3.01-6.97g/100g), calcium (0.27-0.45g/100g) and phosphorus (0.27- 0.59g/100g) all on dry weight basis. These crops play key roles in the food supply system, income generation, improved health and preservation of cultural heritage of the rural household. To fully harness their potentials, the need for more research efforts in the areas of crop improvement, agronomic practices, pests and disease control, nutritional studies, post-production handling and processing was suggested.Keywords: Potato tumeric, production, utilization, nutrient

STUDIES ON THE OPTIMUM MINISETT SIZES FOR RAPID MULTIPLICATION OF RIZGA (PLECTRANTHUS ESCULENTUS), HAUSA POTATO (SOLENOSTERUM ROTUNDIFOLIUM), AND TURMERIC (CURCUMA LONGA) IN NIGERIA

Scarcity of planting materials resulting from low multiplication ratio of minor (underutilized) root and tuber crops rizga (Plectranthus esculentus), turmeric (Curcuma longa), and Hausa potato (Solenosterum rotundifolium) limit their massive production for poverty alleviation and food security. A study on the optimum minisett sizes (3, 4, 5, and 6 g) for rapid multiplication of four minor root and tuber crops (white rizga, black rizga, Hausa potato, and turmeric) were studied in 2003-2004 cropping seasons in Umudike, Nigeria. Minisett sizes were obtained by varying the length of the tubers. The minisetts were planted in polyethylene bags of 25×17×17 cm 3 dimension. The bags were filled with top soil mixed with poultry manure. The soil was saturated with water at 100%-filled capacity. The bags were placed in an open field and planting was done in May of each year. Water was applied twice a week and the experiment was laid out in a randomized complete block design using a 4×4 factorial arrangement with three replications. The crops were harvested four months after planting. The result showed that the number of days to 50% seedling emergence, total number of fresh tuber, and fresh tuber yields were dependent on the weight of minisett. Optimum minisett weight of 5 g sustained the highest number of fresh tubers and fresh tuber yields irrespective of crop species. For rapid multiplication of minor root and tuber crops (rizga, Hausa potato, and turmeric), an optimum minisett weight of 5 g is recommended for increasing and sustaining planting material production in order to achieve food security.

Effect of photoperiod on tuberization in the Livingstone potato ( Plectranthus esculentus N.E.Br. Lamiaceae)

The Livingstone potato ( Plectranthus esculentus N.E.Br.) produces a cluster of edible tubers at the base of the stem that are used as a potato substitute in many areas of Africa. No information is available on factors affecting tuberization in this species. Photoperiod is known to influence storage organ formation in a wide range of crops, and pilot trials indicated that it also played a role in tuberization in P. esculentus. The critical photoperiod for tuber induction, as well as the number of short-day cycles required to induce tubers, were investigated in glasshouse trials using in vitro plants. Nine photoperiod treatments (30-min intervals from 10 to 14 h of light) were applied in the critical photoperiod experiment. To determine the number of short-day cycles required to induce tuberization, plants were exposed to short days (10 h light) for periods ranging from 0 to 20 days at 2-day intervals. Data were collected from both intact plants and sub-apical two-node cuttings made after the experimental treatments were completed. The critical photoperiod for the specific genotype used in this study was between 12.5 and 13 h, with cuttings giving a slightly exaggerated result over that of intact plants. It was established that exposure to four short-day cycles was sufficient to induce tuberization in this species.

Organographic and anatomical evidence that the edible storage organs of Plectranthus esculentus N.E.Br. (Lamiaceae) are stem tubers

Plectranthus esculentus N.E.Br. is a member of the family Lamiaceae, to which many aromatic plants such as the mints and sages belong. It differs from most members of the family in that it produces tuberous subterranean organs at the base of the stem, which can weigh as much as 1.8 kg per tuber. These organs are often used by local people as a food source. Storage organs in plants can be modified roots (carrot and sweet potato), stems (potato), or composed of leave bases (onion). In the case of P. esculentus, there is a difference of opinion as to the exact ontogenetic origin of these organs, and whether they are roots, rhizomes, underground stems or root tubers. According to our observations, these tuberous, positively geotropic organs develop from axillary buds at the base of the stem, and even axillary buds along aerial parts of the stem. Their branching pattern follows the decussate phyllotaxis of the species, and flowering of some tubers has been observed. Anatomical studies show the presence of both primary and secondary vascular bundles arranged in a ring of vascular tissue. Therefore, these organs are true stem tubers.

Effects of DNA extraction procedures on the characterization of a minor tuber crop 'Rizga' (Plectranthus esculentus N. BR.)

Effects of DNA extraction procedures on the characterization of a minor tuber crop 'Rizga' (Plectranthus esculentus N. Br) was demonstrated. Result indicated that evaluation of DNA extraction procedures was necessary in developing a standard protocol that would be suitable for the DNA fingerprinting of P.esculentus clones. Whereas DNA polymorphism was observed in clones under evaluation when extraction procedure Dex 1 was used, there was non observed in the case of Dex2. Furthermore, the estimation of the genetic distances and similarities between some clones of P.esculentus using RAPD profiles obtained from DEx1 procedure indicated that clones VTH and VTHc were similar with a coefficient of 0.83. Clones LK and VTJ had a coefficient of 0.67 followed by VTB and LM with a coefficient of 0.57 as also VTA and VTF with a coefficient of 0.57. Coefficients of the other clones under study are further discussed. Key Words : Characterization, RAPD, tuber, Plectranthus esculentus [Global Jnl Agric Sci Vol.1(1) 2002: 33-40]

Accident prevention in the cowshed.

<h3>Abstract</h3> Recovering biostimulant compounds from by-products of crops is a promising strategy to add value, enhance sustainability, and increase the environmental safety of the agricultural production chain. Here, we report consistent root and shoot growth-stimulating bioactivity present in water-based extracts from Belgian endive forced roots (<i>Cichorium intybus</i> var. <i>foliosum</i>) over two consecutive harvest years. The shoot and the primary root of <i>in vitro</i> cultivated <i>Arabidopsis thaliana</i> treated with Belgian endive extract were about 30% increased in size compared to plants grown under control conditions. The ornamental species <i>Plectranthus esculentus</i> also showed enhanced <i>in vitro</i> shoot and root growth, suggesting bioactivity on a broad range of species. Fractionation of the Belgian endive extracts into aqueous and organic subfractions coupled with bio-activity measurements showed that the principal root and shoot growth-promoting ingredients are primarily water-soluble. NMR-based characterization of the bioactive aqueous fractions revealed the presence of pre-dominantly sugars and organic acids. Malate and sugars were abundant and common to all water fractions, suggesting these molecules contributed to the growth stimulation phenotype. The findings indicate that Belgian endive roots are a source for the development of organic waste-derived biostimulants with potential for application in tissue culture and putatively for soil-grown crop production.