[PHP Nepal Vol 1 Issue 3 Mar 2011] | Bygone, we are using plants as a medication. Diseases like cancer, jaundice, and diabetes are treated by plants like Vinca, Phyllanthes sp. and Gymnema sp. respectively. More than 50 percent of households in the northern part and about 25 percent in the middle part of central Nepal are involved in collecting plants for their medicinal use. These plants are herbs, shrubs, trees, crops or unwanted plants like weeds that grow along with the crops.
As long as human have cultivated plants, weeds have been a problem. Weeds are unwanted for varieties of reasons–they are unpleasant, multitudinous. They restrict light to more desirable plants (especially crop plants), use nutrients from the soil, harbor and spread plant pathogens that infect and degrade the quality of crop or horticultural plants. Some weeds are a nuisance because they have thorns or prickles. Religious and literature texts have also mentioned awful traits of weeds. A Quote from Genesis and a Shakespearean sonnet:
"Cursed is the ground because of you; through painful toil you will eat of it all the days of your life. It will produce thorns and thistles for you, and you will eat the plants of the field. By the sweat of your brow you will eat your food until you return to the ground.”
Thus, the public is exploiting most of the species of weeds. However, weeds have their medicinal values that are unknown to public. They can be used as a medicine in their agro ecosystem. Moreover, weedy plants have their pharmacological efficacy. Young leaves of Dandelion are anti-inflammatory as well as diuretic. Its roots are used for treating acute and chronic hepatitis, liver cirrhosis, and gall bladder disease. Chinese medicine considers Dandelion root specifically useful in the treatment of breast cancer.
Amaranth is very low in saturated fat, cholesterol, and sodium. It is also a good source of dietary fiber, iron, magnesium, phosphorus, and copper. Similarly, Purslane contains pectin known to lower cholesterol. When taken internally or applied topically it helps promote wound healing for boils and burns. It is also a rich source of minerals; particularly potassium.
Several recent studies have proved that weedy plants contain many medically useful active constituents. For example-alkaloids, glycosides, polyphenolics, steroids, tannins, resins, flavoniods, tetraploids, fatty acids. These constituents are able to cure many nutritional disorders and diseases. If weed specimens are properly identified and documented, they can serve the health needs. Additionally, it improves self-reliance in primary health care and prevents the loss of our traditional plants.
It has been found that weeds are harmful for crops as well as toxic for public health. Despite these drawbacks, weeds can become a good source of medicine. For this, people should be made aware of medicinal importance of the weeds. Moreover, the therapeutic qualities and active principles of these plants should be scientifically tested for its safer use.
Nitish Joshi is a student of M.Pharm (Pharmacology) at Mallige College of Pharmacy, Bangalore, India.