Morphological Characteristics and Chemical Composition of Skullcap (Scutellaria lateriflora L.) and Burdock (Arctium lappa L.) Cultivated Under Different Conditions.

Burdock (<em>Arctium lappa </em>L.) and American skullcap (<em>Scutellaria lateriflora</em> L.) are medicinal plants that are highly rich in phytochemicals which contribute towards their therapeutic values. They also possess culinary values as herbal tea. The roots of Burdock are consumed as salad in Europe and Asian continents which are the regions of its origin. Currently, the plant materials of these plants are imported for their medicinal purposes by herbal practitioners and pharmaceutical industries in different countries of the world, including South Africa. However, the cultivation of these plants is lacking in South Africa and Africa as a whole. To achieve consistent supply of quality products and eliminate batch-to-batch variability of plant materials to meet up with the demand. A preliminary study on yield and phytochemical constituents of <em>Arctium lappa</em> L. as influenced by potassium and phosphorous fertilizer application and two different factorial experiments were conducted for Burdock on Takinogawa long cultivar with eight treatments (T1=N423P210K315, T2=N423P280k315, T3=N635P210K315, T4=N635P280K315, T5=N846P210K315, T6=N846P280K315, T7=N1058P210K315 and T8=N1058P280K315 Kg/ha) and five collection times laid out in a completely randomized design, replicated five times under 40% shade net in pot and field experiments. Fertilizer treatments were split into two equal doses at seedling stage and four weeks after transplanting. Data on morphological characteristics and yield were collected and analysed using SAS software. There was a significant (P&lt;0.05) difference across fertilizer treatments on morphological characteristics and time of collection for both pot and field experiments. Significant differences (P&lt;0.05) were also recorded on the yield parameters investigated. Treatment (N635P210 K315 Kg/ha) significantly outperformed the other treatments in the pot experiment. While for the field experiment, treatment (N846P280K315Kg/ha) significantly outperformed the other treatments. Furthermore, phytochemical constituents, antioxidant and anti-inflammatory activities of aqueous and methanol leaf and root extracts of burdock as influenced by fertilizer treatments were assessed. Result of phytochemical screening were fairly rich indicating a positive test for phenols, flavonoids, tannins, saponins and glycosides. Significant differences (p&lt;0.05) were observed on total phenolic content (TPC), total flavonoids content (TFC) and condense tannins (PAC) on both aqueous and methanol leaf and root extracts in both pot and field studies. The nutritional constituents of the burdock root and leaf samples in both pot and field experiments were significant (P&lt;0.05) except for root lipid content for pot experiment and leaf ash content for field experiment which were not significant (P&gt;0.05). For antioxidant activities, 2,2-diphyl-1-picrythydraxyl, Nitric oxide and hydrogen peroxide were significant (p&lt;0.05) for aqueous and methanol leaf and root extracts for pot and field experiments among treatment combinations. Overall, scavenging activity for treatment combinations with a lower level of phosphorous (P210 Kg/ha) recorded a lower IC50 values compared to those with higher level of phosphorous (P280 Kg/ha). Furthermore, anti-inflammatory activity for aqueous and methanol dried root and leaf extracts for pot and field experiments demonstrated significant differences (p&lt;0.05) among treatment combinations. GC-MS analysis of essential oil for burdock root validated a variation in chemical composition among the different treatment combinations. Interestingly, the greatest variation was demonstrated by T7 with a total of 20 compounds identified; followed by T3 with 19 compounds, T4, T5, T6 and T8 with 14compounds while T1 and T2 had 13 compounds. Similarly, a factorial pot experiment was conducted for <em>S. lateriflora</em> with the same procedure and application, but with different treatments (T1=N350P213K213, T2=N350P320K213, T3=N525P213K213, T4=N525P320K213, T5=N700P213K213, T6=N700P320K213, T7=N800P213K213 and T8=N800P230K213 Kg/ha). Fertilizer treatments and time of collection had a significant (p&lt;0.05) effect on the vegetative growth parameters investigated. Significant (p&lt;0.05) effect was also recorded on biomass yield and total flavonoid contents across the different phenological stages. Fertilizer range (N525-N700 with P213-P320 and K213Kg/ha) had the highest influence on growth and yield attributes. Furthermore, phytochemical constituents, antioxidant, and anti-inflammatory activities of aqueous and methanol leaf extracts of American skullcap as influenced by fertilizer treatments were assessed. The results of phytochemical screening were quite rich at a varying degree, demonstrating the presence of flavonoids, tannins, saponins, phenols, alkaloids, terpenoids and steroids. The highest concentration of total phenolic content was recorded at the post flowering stage (41.65%) followed by the pre-flowering stage (33.83%) and the least at flowering stage (24.52%). Also, total flavonoid content recorded the highest concentration at post flowering stage (38.2%), followed by pre-flowering stage (34.2%) and the least at flowering stage (27.6%). However, for condense tannins, the highest concentration was recorded at the pre-flowering stage (38.5%) followed by the post flowering stage (31.2%) and the least at the flowering stage (30.3%). Also, the nutritional constituents of the leaves were significant (P&lt;0.05). The antioxidant and anti-inflammatory activities exhibited in aqueous, and methanol dried leaf extracts had significant (p&lt;0.05) scavenging and anti-inflammatory activities demonstrated by the IC50 values. T5 had the lowest IC50 values for all the antioxidant assays. However, T4 recorded the most ideal anti-inflammatory activity with IC50 value (352.8 μg/ml) for aqueous extract and T7 (834.1 μg/ml) for methanol extract. Overall, treatments with lower supplementary phosphorous (P1=213kg/ha) recorded a higher concentration of total phenolic, flavonoids and condense tannins, ash, and lipid contents than those with higher supplementary phosphorous (P2=320kg/ha). For carbohydrate content, treatments with high supplementary phosphorus had a higher yield response than those with lower supplementary phosphorous

牛蒡（*Arctium lappa* L.）和美洲黄芩（*Scutellaria lateriflora* L.）是富含植物化学物（phytochemicals）的药用植物，这些成分赋予其治疗价值；二者亦具有作为草药茶的食用价值。牛蒡根在其原产地欧洲与亚洲大陆被作为沙拉食用。目前，包括南非在内的全球多国草药从业者及制药行业均进口这些植物原料用于药用，但南非乃至整个非洲均缺乏此类植物的规模化栽培。

为实现优质产品的稳定供应、消除植物原料的批次间差异以满足需求，本研究开展了钾肥与磷肥施用对牛蒡（*Arctium lappa* L.）产量及植物化学物成分影响的初步研究，并针对牛蒡“泷川长”品种进行两项析因实验：设置8个处理组（T1=N423P210K315、T2=N423P280K315、T3=N635P210K315、T4=N635P280K315、T5=N846P210K315、T6=N846P280K315、T7=N1058P210K315、T8=N1058P280K315 kg/ha）与5个采样时间点，在盆栽及田间实验中采用完全随机设计（重复5次），且实验在40%遮光网下进行。肥料分两次等量施用，分别于苗期及移栽后4周实施。收集形态特征与产量数据，通过SAS软件进行分析。

盆栽与田间实验中，不同肥料处理对形态特征及采样时间的影响均存在显著差异（P<0.05）；所测产量参数亦存在显著差异（P<0.05）。盆栽实验中，N635P210K315 kg/ha处理组表现显著优于其他组；田间实验中，N846P280K315 kg/ha处理组表现显著优于其他组。

此外，评估了肥料处理对牛蒡叶、根水提物及甲醇提取物中植物化学物成分、抗氧化活性与抗炎活性的影响。植物化学物筛选结果显示，提取物中酚类、黄酮类、单宁、皂苷及糖苷均呈阳性，含量较丰富。盆栽与田间研究中，叶、根水提物及甲醇提取物的总酚含量（TPC）、总黄酮含量（TFC）与缩合单宁（PAC）均存在显著差异（p<0.05）。

盆栽与田间实验中，牛蒡根、叶样品的营养成分均存在显著差异（P<0.05），但盆栽实验的根脂质含量与田间实验的叶灰分含量除外（P>0.05）。抗氧化活性方面，不同处理组合下，叶、根水提物及甲醇提取物对2,2-二苯基-1-苦基肼（DPPH）、一氧化氮及过氧化氢的清除活性均存在显著差异（p<0.05）。总体而言，低磷肥水平（P210 kg/ha）处理组的清除活性对应IC50值（半数抑制浓度，IC50）低于高磷肥水平（P280 kg/ha）处理组。

盆栽与田间实验中，干燥根、叶水提物及甲醇提取物的抗炎活性在不同处理组合间存在显著差异（p<0.05）。牛蒡根精油的气相色谱-质谱联用（GC-MS）分析证实，不同处理组合的化学成分存在变异：T7处理组变异最大（鉴定出20种化合物），其次为T3（19种）、T4/T5/T6/T8（14种），T1与T2处理组各13种。

类似地，针对美洲黄芩（*Scutellaria lateriflora* L.）开展析因盆栽实验（流程与施用方式相同，处理组不同）：T1=N350P213K213、T2=N350P320K213、T3=N525P213K213、T4=N525P320K213、T5=N700P213K213、T6=N700P320K213、T7=N800P213K213、T8=N800P230K213 kg/ha。肥料处理与采样时间对营养生长参数存在显著影响（p<0.05）；不同物候期的生物量产量与总黄酮含量亦存在显著差异（p<0.05）。N525-N700、P213-P320且K213 kg/ha的肥料组合对生长及产量性状影响最大。

此外，评估了肥料处理对美洲黄芩叶水提物及甲醇提取物中植物化学物成分、抗氧化活性与抗炎活性的影响。植物化学物筛选结果显示，提取物中黄酮类、单宁、皂苷、酚类、生物碱、萜类及甾体化合物均有不同程度存在，含量较丰富。总酚含量在花后期最高（41.65%），其次为花前期（33.83%）、花期（24.52%）；总黄酮含量在花后期最高（38.2%），其次为花前期（34.2%）、花期（27.6%）；缩合单宁含量在花前期最高（38.5%），其次为花后期（31.2%）、花期（30.3%）。叶片营养成分存在显著差异（P<0.05）。

干燥叶水提物及甲醇提取物表现出显著的清除活性与抗炎活性（p<0.05），可通过IC50值体现。T5处理组在所有抗氧化实验中的IC50值最低；T4处理组水提物抗炎活性最理想（IC50=352.8 μg/ml），T7处理组甲醇提取物抗炎活性最理想（IC50=834.1 μg/ml）。

总体而言，低补充磷肥（P1=213 kg/ha）处理组的总酚、黄酮、缩合单宁、灰分及脂质含量高于高补充磷肥（P2=320 kg/ha）处理组；碳水化合物含量方面，高补充磷肥处理组的产量响应高于低补充磷肥处理组。