Michael Pillay

Phenotypic Relationships Among Growth, Yield, and Black Leaf Streak Disease Responses of Musa Genotypes

Abstract This study was carried out to assess the phenotypic correlations among phenological traits, yield, and black sigatoka disease (BSD) response of 14 Musa genotypes grown for three cropping cycles in three high-altitude sites that varied in temperature and annual rainfall. Preflowering plant growth had stronger relationship with bunch weight only in low yielding (LY) genotypes. In contrast, foliage traits and BSD resistance status of plants at flowering were more associated with bunch weight in high yielding (HY) genotypes. For example, plant size at flowering was positively associated with bunch weight in LY genotypes in all the MET sites (with r ranging between 0.58** and 0.89**), but for HY genotypes, the number of green leaves at harvest was significantly correlated with bunch weight in all sites (with r ranging between 0.75** and 0.88**). Also, bunch yield traits had higher inter-crop cycle r-values (ranging between 0.60** and 0.90**) than the foliage traits (r ≥0.52** ≤0.84**). The correlation coefficients between bunch weight and number of fruits per bunch in all sites and cropping cycles were significant and positive, ranging between 0.64** and 0.91**. Furthermore, principal component analysis (PCA) and stepwise multiple regression analysis retained the number of fruits per bunch (FNGS) and number of standing leaves at harvest (NSLH) as the most reliable predictors of bunch weight in this study. Thus, FNGS and NSLH could be used as indirect selection criteria for bunch weight in future breeding efforts.

Influence of solar water disinfection on immunity against cholera – a review

Cholera remains a problem in developing countries. This is attributed to the unavailability of proper water treatment, sanitary infrastructure and poor hygiene. As a consequence, countries facing cholera outbreaks rely on interventions such as the use of oral rehydration therapy and antibiotics to save lives. In addition to vaccination, the provision of chlorine tablets and hygiene sensitization drives have been used to prevent new cholera infections. The implementation of these interventions remains a challenge due to constraints associated with the cost, ease of use and technical knowhow. These challenges have been reduced through the use of solar water disinfection (SODIS). The success of SODIS in mitigating the risk associated with the consumption of waterborne pathogens has been associated with solar irradiation. This has prompted a lot of focus on the solar component for enhanced disinfection. However, the role played by the host immune system following the consumption of solar-irradiated water pathogens has not received any significant attention. The mode of inactivation resulting from the exposure of microbiologically contaminated water results in immunologically important microbial states as well as components. In this review, the possible influence that solar water disinfection may have on the immunity against cholera is discussed.

The Effect of Solar Irradiated Vibrio cholerae on the Secretion of Pro-Inflammatory Cytokines and Chemokines by the JAWS II Dendritic Cell Line In Vitro

The use of solar irradiation to sterilize water prior to its consumption has resulted in the reduction of water related illnesses in waterborne disease endemic communities worldwide. Currently, research on solar water disinfection (SODIS) has been directed towards understanding the underlying mechanisms through which solar irradiation inactivates the culturability of microorganisms in water, enhancement of the disinfection process, and the health impact of SODIS water consumption. However, the immunological consequences of SODIS water consumption have not been explored. In this study, we investigated the effect that solar irradiated V. cholerae may have had on the secretion of cytokines and chemokines by the JAWS II dendritic cell line in vitro. The JAWS II dendritic cell line was stimulated with the different strains of V. cholerae that had been: (i) prepared in PBS, (ii) inactivated through a combination of heat and chemical, (iii) solar irradiated, and (iv) non-solar irradiated, in bottled water. As controls, LPS (1 μg/ml) and CTB (1 μg/ml) were used as stimulants. After 48 hours of stimulation the tissue culture media from each treatment was qualitatively and quantitatively analysed for the presence of IL-1α, IL-1β, IL-6, IL-7, IL-10, IL-12p40, IL-12p70, IL-15, MIP-1α, MIP-1β, MIP-2, RANTES, TNF-α, IL-23 and IL-27. Results showed that solar irradiated cultures of V. cholerae induced dendritic cells to secrete significant (p<0.05) levels of pro-inflammatory cytokines in comparison to the unstimulated dendritic cells. Furthermore, the amount of pro-inflammatory cytokines secreted by the dendritic cells in response to solar irradiated cultures of V. cholerae was not as high as observed in treatments involving non-solar irradiated cultures of V. cholerae or LPS. Our results suggest that solar irradiated microorganisms are capable of inducing the secretion of pro-inflammatory cytokines and chemokines. This novel finding is key towards understanding the possible immunological consequences of consuming SODIS treated water.

Advances in Regenerative Medicine and Tissue Engineering: Innovation and Transformation of Medicine

Humans and animals lose tissues and organs due to congenital defects, trauma, and diseases. The human body has a low regenerative potential as opposed to the urodele amphibians commonly referred to as salamanders. Globally, millions of people would benefit immensely if tissues and organs can be replaced on demand. Traditionally, transplantation of intact tissues and organs has been the bedrock to replace damaged and diseased parts of the body. The sole reliance on transplantation has created a waiting list of people requiring donated tissues and organs, and generally, supply cannot meet the demand. The total cost to society in terms of caring for patients with failing organs and debilitating diseases is enormous. Scientists and clinicians, motivated by the need to develop safe and reliable sources of tissues and organs, have been improving therapies and technologies that can regenerate tissues and in some cases create new tissues altogether. Tissue engineering and/or regenerative medicine are fields of life science employing both engineering and biological principles to create new tissues and organs and to promote the regeneration of damaged or diseased tissues and organs. Major advances and innovations are being made in the fields of tissue engineering and regenerative medicine and have a huge impact on three-dimensional bioprinting (3D bioprinting) of tissues and organs. 3D bioprinting holds great promise for artificial tissue and organ bioprinting, thereby revolutionizing the field of regenerative medicine. This review discusses how recent advances in the field of regenerative medicine and tissue engineering can improve 3D bioprinting and vice versa. Several challenges must be overcome in the application of 3D bioprinting before this disruptive technology is widely used to create organotypic constructs for regenerative medicine.

Anti-nutrient analysis of 30 Bambara groundnut (Vigna subterranea) accessions in South Africa

ABSTRACT Bambara groundnut is a leguminous crop that originated in West Africa. It is a drought-tolerant crop and has the potential to provide improved food and nutritional security in the dry areas of Africa. However, the plant contains anti-nutritional factors that affect its food value chain. The objective of this study was to assess the content of four major anti-nutritional factors in 30 bambara groundnut accessions in South Africa. The seeds of the bambara groundnut landraces were ground to make a fine powder and assessed for condensed tannins (CTs), phytic acid phosphate (PAP), polyphenol, and trypsin inhibitor content. Each assay was done in triplicate. The content of the four anti-nutritional compounds varied widely among the bambara groundnut accessions. The mean values for CTs ranged between 0.2 and 6.2 mg/g of prodephinidin equivalent, whereas that of the PAP was between 1.4 and 4.9 mg/g. A low mean polyphenol content of 0.4 mg/g of GA (gallic acid) equivalent was observed among the accessions. The level of trypsin inhibitor ranged from 5.3 to 73.4 TI/mg. With the exception of CTs and trypsin inhibitor, no significant correlation was observed among the four anti-nutritional factors assessed in this study. Generally, higher levels of anti-nutrients were observed in this study compared with certain studies reported earlier.

Anticancer activity of crude acetone and water extracts of Tulbaghia violacea on human oral cancer cells

Objective: To evaluate the anticancer activity of crude acetone and water leaf extracts of Tulbaghia violacea on a human oral cancer cell line (KB). Methods: The antioxidant activity of the leaf extracts was evaluated by using the DPPH assay while the anti-proliferative activity was assessed by using the MTT assay. The morphological characteristics of apoptotic cells were examined by using the dual acridine orange/ethidium bromide staining. Flow cytometry was used to evaluate the induction of multi-caspase activity and changes in the cell cycle. Results: The acetone and water extracts exhibited antioxidant activity in a concentration dependent manner. The extracts inhibited the growth of the KB cell line with IC50 values of 0.2 mg/mL and 1 mg/mL, respectively for acetone and water. Morphological changes such as cell shrinkage, rounding and formation of membrane blebs were observed in the treated cells. In acridine orange/ethidium bromide staining, the number of apoptotic cells increased as the concentration of the extracts increased. The activation of multi-caspase activity in KB cells treated with Tulbaghia violacea extracts was concentration dependent, leading to cell death by apoptosis and cell cycle arrest at the G2/M phase. Conclusions: The acetone and water extracts of Tulbaghia violacea appear to have anti-cancer activity against human oral cancer cells and need to be investigated further.